From 323892b48ea5d4177242ad1187879dfad4e01aa6 Mon Sep 17 00:00:00 2001
From: chewiebug <jwu@gmx.ch>
Date: Tue, 2 Jan 2018 15:40:37 +0100
Subject: [PATCH 1/4] #155 refactor DataReaderUnifiedJvmLogging to prepare
 reading heap details if gc,heap information is present

---
 .../gcviewer/imp/AbstractDataReaderSun.java   |   4 +-
 .../perf/gcviewer/imp/DataReaderTools.java    |  11 +-
 .../imp/DataReaderUnifiedJvmLogging.java      | 218 +++++++++++-------
 .../perf/gcviewer/model/AbstractGCEvent.java  |  17 +-
 .../perf/gcviewer/UnittestHelper.java         |  76 ++++--
 .../impl/GCModelSeriesLoaderImplTest.java     |  25 +-
 .../ctrl/impl/GcSeriesLoaderTest.java         |  34 +--
 .../gcviewer/ctrl/impl/TestGCModelLoader.java |  11 +-
 .../impl/TestGCModelLoaderController.java     |  39 ++--
 .../gcviewer/imp/TestDataReaderFacade.java    |  56 ++---
 .../gcviewer/imp/TestDataReaderFactory.java   |  12 +-
 .../gcviewer/imp/TestDataReaderHPUX1_2.java   |   8 +-
 .../gcviewer/imp/TestDataReaderHPUX1_4_1.java |   8 +-
 .../gcviewer/imp/TestDataReaderIBM1_2_2.java  |   8 +-
 .../gcviewer/imp/TestDataReaderIBM1_3_1.java  |   8 +-
 .../gcviewer/imp/TestDataReaderIBM1_4_2.java  |   8 +-
 .../gcviewer/imp/TestDataReaderIBMJ9_5_0.java |  10 +-
 .../imp/TestDataReaderIBM_J9_R26.java         |   3 +-
 .../imp/TestDataReaderIBM_J9_R27.java         |   3 +-
 .../imp/TestDataReaderIBM_J9_R28.java         |   3 +-
 .../imp/TestDataReaderIBMi5OS1_4_2.java       |   8 +-
 .../imp/TestDataReaderJRockit1_4_2.java       |   8 +-
 .../imp/TestDataReaderJRockit1_5_0.java       |   8 +-
 .../imp/TestDataReaderJRockit1_6_0.java       |   8 +-
 .../imp/TestDataReaderSun1_3_1_19.java        |   8 +-
 .../gcviewer/imp/TestDataReaderSun1_4_0.java  |  15 +-
 .../gcviewer/imp/TestDataReaderSun1_5_0.java  |   8 +-
 .../gcviewer/imp/TestDataReaderSun1_6_0.java  |  23 +-
 .../imp/TestDataReaderSun1_6_0G1.java         |  23 +-
 .../gcviewer/imp/TestDataReaderSun1_7_0.java  |  11 +-
 .../imp/TestDataReaderSun1_7_0G1.java         |  25 +-
 .../gcviewer/imp/TestDataReaderSun1_8_0.java  |   8 +-
 .../imp/TestDataReaderSun1_8_0G1.java         |  10 +-
 .../gcviewer/imp/TestDataReaderUJLCMS.java    |  25 +-
 .../gcviewer/imp/TestDataReaderUJLG1.java     |  25 +-
 .../imp/TestDataReaderUJLParallel.java        |  25 +-
 .../gcviewer/imp/TestDataReaderUJLSerial.java |  23 +-
 .../imp/TestDataReaderUJLShenandoah.java      |  24 +-
 .../gcviewer/model/GcResourceSeriesTest.java  |  27 +--
 .../perf/gcviewer/model/TestGCModel.java      |  27 +--
 .../util/TestHttpUrlConnectionHelper.java     |   5 +-
 .../sample-ujl-cms-gc-defaults.txt            |   2 +-
 42 files changed, 484 insertions(+), 424 deletions(-)

diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
index 37308549..67416505 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
@@ -301,8 +301,8 @@ protected ExtendedType parseType(String line, ParseInformation pos) throws Parse
     }
 
 
-    protected ExtendedType extractTypeFromParsedString(String typeName) throws UnknownGcTypeException {
-        return getDataReaderTools().extractTypeFromParsedString(typeName);
+    protected ExtendedType extractTypeFromParsedString(String typeName) {
+        return getDataReaderTools().parseTypeWithCause(typeName);
     }
 
     /**
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
index 7b98a8b4..29f2c50b 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
@@ -60,7 +60,7 @@ else if ('G' == memUnit) {
      * @throws UnknownGcTypeException If <code>typeString</code> can't be converted to an <code>ExtendedType</code>
      */
     public ExtendedType parseType(String typeString) throws UnknownGcTypeException {
-        ExtendedType gcType = extractTypeFromParsedString(typeString.trim());
+        ExtendedType gcType = parseTypeWithCause(typeString.trim());
         if (gcType == null) {
             throw new UnknownGcTypeException(typeString);
         }
@@ -68,7 +68,14 @@ public ExtendedType parseType(String typeString) throws UnknownGcTypeException {
         return gcType;
     }
 
-    public ExtendedType extractTypeFromParsedString(String typeName) {
+    /**
+     * Same as @{link {@link #parseType(String)}}, but returns <code>null</code> instead of exception, if no type could
+     * be found.
+     *
+     * @param typeName string representation of the gc event
+     * @return <code>ExtendedType</code> representing <code>typeString</code>, or <code>null</code> if none could be found
+     */
+    public ExtendedType parseTypeWithCause(String typeName) {
         typeName = typeName.trim();
         ExtendedType extendedType = null;
         String lookupTypeName = typeName.endsWith("--")
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
index 2d042b0e..b05fafbb 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
@@ -13,10 +13,13 @@
 import java.util.stream.Stream;
 
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Concurrency;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.GcPattern;
 import com.tagtraum.perf.gcviewer.model.ConcurrentGCEvent;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.util.NumberParser;
 
 /**
  * DataReaderUnifiedJvmLogging can parse all gc events of unified jvm logs with default decorations.
@@ -38,49 +41,52 @@
  */
 public class DataReaderUnifiedJvmLogging extends AbstractDataReader {
 
+    // matches the whole line and extracts decorators from it (decorators always appear between [] and are independent of the gc algorithm being logged)
     // Input: [0.693s][info][gc           ] GC(0) Pause Init Mark 1.070ms
-    // Group 1: 0.693
-    // Group 2: Pause Init Mark
-    // Group 3: 1.070 -> optional
-    // Regex: ^\[([^s\]]*)[^\-]*\)[ ]([^\-]*)[ ]([0-9]+[.,][0-9]+)
-    private static final Pattern PATTERN_WITHOUT_HEAP = Pattern.compile(
-            "^\\[([^s\\]]*)[^\\-]*\\)[ ]([^\\d]*)(([0-9]+[.,][0-9]+)|$)");
-
-    // Input: [13.522s][info][gc            ] GC(708) Concurrent evacuation  4848M->4855M(4998M) 2.872ms
-    // Group 1: 13.522
-    // Group 2: Concurrent evacuation
-    // Group 3: 4848M->4855M(4998M)
-    // Group 4: 2.872
-    // Regex: ^\[([^s\]]*).*\)[ ](.*)[ ]([0-9]+[BKMG]\-\>[0-9]+[BKMG]\([0-9]+[BKMG]\)) ([0-9]+[.,][0-9]+)
-    private static final Pattern PATTERN_WITH_HEAP = Pattern.compile(
-            "^\\[([^s\\]]*).*\\)[ ](.*)[ ]([0-9]+[BKMG]\\-\\>[0-9]+[BKMG]\\([0-9]+[BKMG]\\)) ([0-9]+[.,][0-9]+)");
-
-    // Input: 4848M->4855M(4998M)
+    // Group 1 / time: <empty> (optional group, no full timestamp present)
+    // Group 2 / uptime: 0.693 (optional group, present in this example)
+    // Group 3 / level: info
+    // Group 4 / tags: gc
+    // Group 5 / gcnumber: 0
+    // Group 6 / tail: Pause Init Mark 1.070ms
+    // Regex: ^(?:\[(?<time>[0-9-T:.+]*)])?(?:\[(?<uptime>[^s]*)s])?\[(?<level>[^]]+)]\[(?:(?<tags>[^] ]+)[ ]*)][ ]GC\((?<gcnumber>[0-9]+)\)[ ](?<type>([-.a-zA-Z ()]+|[a-zA-Z1 ()]+))(?:(?:[ ](?<tail>[0-9]{1}.*))|$)
+    //   note for the <type> part: easiest would have been to use [^0-9]+, but the G1 events don't fit there, because of the number in their name
+    private static final Pattern PATTERN_DECORATORS = Pattern.compile(
+            "^(?:\\[(?<time>[0-9-T:.+]*)])?(?:\\[(?<uptime>[^s]*)s])?\\[(?<level>[^]]+)]\\[(?:(?<tags>[^] ]+)[ ]*)][ ]GC\\((?<gcnumber>[0-9]+)\\)[ ](?<type>[-.a-zA-Z ()]+|[a-zA-Z1 ()]+)(?:(?:[ ](?<tail>[0-9]{1}.*))|$)"
+    );
+    private static final String GROUP_DECORATORS_TIME = "time";
+    private static final String GROUP_DECORATORS_UPTIME = "uptime";
+    private static final String GROUP_DECORATORS_LEVEL = "level";
+    private static final String GROUP_DECORATORS_TAGS = "tags";
+    private static final String GROUP_DECORATORS_GC_NUMBER = "gcnumber";
+    private static final String GROUP_DECORATORS_GC_TYPE = "type";
+    private static final String GROUP_DECORATORS_TAIL = "tail";
+
+    private static final String PATTERN_PAUSE_STRING = "([0-9]+[.,][0-9]+)ms";
+    // Input: 1.070ms
+    // Group 1: 1.070
+    private static final Pattern PATTERN_PAUSE = Pattern.compile("^" + PATTERN_PAUSE_STRING);
+
+    private static final int GROUP_PAUSE = 1;
+
+    // Input: 4848M->4855M(4998M) 2.872ms
     // Group 1: 4848
-    // Group 2: 4855
-    // Group 3: 4998
-    // Regex: ([0-9]+)[BKMG]\-\>([0-9]+)[BKMG]\(([0-9]+)[BKMG]\)
-    private static final Pattern PATTERN_HEAP_CHANGES = Pattern.compile(
-            "([0-9]+)([BKMG])->([0-9]+)([BKMG])\\(([0-9]+)([BKMG])\\)");
-
-    // Input: 2017-08-30T23:22:47.357+0300
-    // Regex: ^\d{4}\-\d\d\-\d\d[tT][\d:\.]*?(?:[zZ]|[+\-]\d\d:?\d\d)?$
-    private static final Pattern PATTERN_ISO8601_DATE = Pattern.compile(
-            "^\\d{4}\\-\\d\\d\\-\\d\\d[tT][\\d:\\.]*?(?:[zZ]|[+\\-]\\d\\d:?\\d\\d)?$");
-
-    private static final int NO_HEAP_TIMESTAMP = 1;
-    private static final int NO_HEAP_EVENT_NAME = 2;
-    private static final int NO_HEAP_DURATION = 3;
-    private static final int WITH_HEAP_TIMESTAMP = 1;
-    private static final int WITH_HEAP_EVENT_NAME = 2;
-    private static final int WITH_HEAP_MEMORY = 3;
-    private static final int WITH_HEAP_DURATION = 4;
-    private static final int HEAP_BEFORE = 1;
-    private static final int HEAP_BEFORE_UNIT = 2;
-    private static final int HEAP_AFTER = 3;
-    private static final int HEAP_AFTER_UNIT = 4;
-    private static final int HEAP_CURRENT_TOTAL = 5;
-    private static final int HEAP_CURRENT_TOTAL_UNIT = 6;
+    // Group 2: M
+    // Group 3: 4855
+    // Group 4: M
+    // Group 5: 4998
+    // Group 6: M
+    // Group 7: 1.070
+    private static final Pattern PATTERN_MEMORY_PAUSE = Pattern.compile("^(([0-9]+)([BKMG])->([0-9]+)([BKMG])\\(([0-9]+)([BKMG])\\)) " + PATTERN_PAUSE_STRING);
+
+    private static final int GROUP_MEMORY = 1;
+    private static final int GROUP_MEMORY_BEFORE = 2;
+    private static final int GROUP_MEMORY_BEFORE_UNIT = 3;
+    private static final int GROUP_MEMORY_AFTER = 4;
+    private static final int GROUP_MEMORY_AFTER_UNIT = 5;
+    private static final int GROUP_MEMORY_CURRENT_TOTAL = 6;
+    private static final int GROUP_MEMORY_CURRENT_TOTAL_UNIT = 7;
+    private static final int GROUP_MEMORY_PAUSE = 8;
 
     /** list of strings, that must be part of the gc log line to be considered for parsing */
     private static final List<String> INCLUDE_STRINGS = Arrays.asList("[gc ", "[gc]");
@@ -117,23 +123,18 @@ public GCModel read() throws IOException {
     private AbstractGCEvent<?> parseEvent(String line) {
         AbstractGCEvent<?> event = null;
 
-        Matcher noHeapMatcher = PATTERN_WITHOUT_HEAP.matcher(line);
-        Matcher withHeapMatcher = PATTERN_WITH_HEAP.matcher(line);
+        Matcher decoratorsMatcher = PATTERN_DECORATORS.matcher(line);
         try {
-            event = line.contains("Concurrent") ? new ConcurrentGCEvent() : new GCEvent();
-            if (noHeapMatcher.find()) {
-                AbstractGCEvent.ExtendedType type = getDataReaderTools().parseType(noHeapMatcher.group(NO_HEAP_EVENT_NAME));
-                event.setExtendedType(type);
-                setPauseAndDateOrTimestamp(event, noHeapMatcher.group(NO_HEAP_TIMESTAMP), noHeapMatcher.groupCount() > 2 ? noHeapMatcher.group(NO_HEAP_DURATION) : null);
-            } else if (withHeapMatcher.find()) {
-                AbstractGCEvent.ExtendedType type = getDataReaderTools().parseType(withHeapMatcher.group(WITH_HEAP_EVENT_NAME));
-                event.setExtendedType(type);
-                setPauseAndDateOrTimestamp(event, withHeapMatcher.group(WITH_HEAP_TIMESTAMP), withHeapMatcher.group(WITH_HEAP_DURATION));
-                addHeapDetailsToEvent(event, withHeapMatcher.group(WITH_HEAP_MEMORY));
-            } else {
-                // prevent incomplete event from being added to the GCModel
-                event = null;
-                getLogger().warning(String.format("Failed to parse line number %d (line=\"%s\")", in.getLineNumber(), line));
+            event = createGcEventWithStandardDecorators(decoratorsMatcher, line);
+            if (event != null) {
+                String tail = decoratorsMatcher.group(GROUP_DECORATORS_TAIL);
+                if (event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE)) {
+                    handleGcPauseTail(line, event, tail);
+                } else if (event.getExtendedType().getPattern().equals(GcPattern.GC_MEMORY_PAUSE)) {
+                    handleGcMemoryPauseTail(line, event, tail);
+                } else if (event.getExtendedType().getPattern().equals(GcPattern.GC) || event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE_DURATION)) {
+                    handleGcTail(line, tail);
+                }
             }
         } catch (UnknownGcTypeException | NumberFormatException e) {
             // prevent incomplete event from being added to the GCModel
@@ -144,41 +145,90 @@ private AbstractGCEvent<?> parseEvent(String line) {
         return event;
     }
 
-    /**
-     * @param event                     GC event to which pause and timestamp information is added
-     * @param pauseAsString             Pause information from regex group as string
-     * @param dateOrTimeStampAsString   Date- or timestamp information from regex group as string
-     */
-    private void setPauseAndDateOrTimestamp(AbstractGCEvent<?> event, String dateOrTimeStampAsString, String pauseAsString) {
-        if (pauseAsString != null && pauseAsString.length() > 0) {
-            double pause = Double.parseDouble(pauseAsString.replace(",", "."));
-            event.setPause(pause / 1000);
+    private void handleGcTail(String line, String tail) {
+        if (!(tail == null)) {
+            getLogger().warning(String.format("Unexpected tail present in the end of line number %d (expected nothing to be present, tail=\"%s\"; line=\"%s\")", in.getLineNumber(), tail, line));
         }
-        if (PATTERN_ISO8601_DATE.matcher(dateOrTimeStampAsString).find()) {
-            ZonedDateTime dateTime = ZonedDateTime.parse(dateOrTimeStampAsString, AbstractDataReaderSun.DATE_TIME_FORMATTER);
-            event.setDateStamp(dateTime);
+    }
+
+    private void handleGcMemoryPauseTail(String line, AbstractGCEvent<?> event, String tail) {
+        Matcher memoryPauseMatcher = PATTERN_MEMORY_PAUSE.matcher(tail);
+        if (memoryPauseMatcher.find()) {
+            setPause(event, memoryPauseMatcher.group(GROUP_MEMORY_PAUSE));
+            setMemory(event, memoryPauseMatcher);
         } else {
-            double timestamp = Double.parseDouble(dateOrTimeStampAsString.replace(",", "."));
-            event.setTimestamp(timestamp);
+            getLogger().warning(String.format("Expected memory and pause in the end of line number %d (line=\"%s\")", in.getLineNumber(), line));
+        }
+    }
+
+    private void handleGcPauseTail(String line, AbstractGCEvent<?> event, String tail) {
+        // G1 and CMS algorithms have "gc" tagged concurrent events, that are actually the start of an event
+        // (I'd expect them to be tagged "gc,start", as this seems to be the case for the Shenandoah algorithm)
+        // G1: Concurrent Cycle (without pause -> start of event; with pause -> end of event)
+        // CMS: all concurrent events
+
+        // this is the reason, why a "null" tail is accepted here
+        if (tail != null) {
+            Matcher pauseMatcher = PATTERN_PAUSE.matcher(tail);
+            if (pauseMatcher.find()) {
+                setPause(event, pauseMatcher.group(GROUP_PAUSE));
+            } else {
+                getLogger().warning(String.format("Expected only pause in the end of line number %d  (line=\"%s\")", in.getLineNumber(), line));
+            }
         }
     }
 
     /**
-     * @param event        GC event to which the heap change information is added
-     * @param memoryString Memory changes in format 100M->80M(120M) where 100M-before, 80M-after, 120M-max
+     * Returns an instance of AbstractGcEvent (GCEvent or ConcurrentGcEvent) with all decorators present filled in
+     * or <code>null</code> if the line could not be matched.
+     * @param decoratorsMatcher matcher for decorators to be used for GcEvent creation
+     * @param line current line to be parsed
+     * @return Instance of <code>AbstractGcEvent</code> or <code>null</code> if the line could not be matched.
      */
-    private void addHeapDetailsToEvent(AbstractGCEvent<?> event, String memoryString) {
-        Matcher matcher = PATTERN_HEAP_CHANGES.matcher(memoryString);
-        if (matcher.find()) {
-            event.setPreUsed(getDataReaderTools().getMemoryInKiloByte(
-                    Integer.parseInt(matcher.group(HEAP_BEFORE)), matcher.group(HEAP_BEFORE_UNIT).charAt(0), memoryString));
-            event.setPostUsed(getDataReaderTools().getMemoryInKiloByte(
-                    Integer.parseInt(matcher.group(HEAP_AFTER)), matcher.group(HEAP_AFTER_UNIT).charAt(0), memoryString));
-            event.setTotal(getDataReaderTools().getMemoryInKiloByte(
-                    Integer.parseInt(matcher.group(HEAP_CURRENT_TOTAL)), matcher.group(HEAP_CURRENT_TOTAL_UNIT).charAt(0), memoryString));
-            event.setExtendedType(event.getExtendedType());
+    private AbstractGCEvent<?> createGcEventWithStandardDecorators(Matcher decoratorsMatcher, String line) throws UnknownGcTypeException {
+        if (decoratorsMatcher.find()) {
+            AbstractGCEvent.ExtendedType type = getDataReaderTools().parseType(decoratorsMatcher.group(GROUP_DECORATORS_GC_TYPE));
+
+            AbstractGCEvent<?> event = type.getConcurrency().equals(Concurrency.CONCURRENT) ? new ConcurrentGCEvent() : new GCEvent();
+            event.setExtendedType(type);
+            setDateStampIfPresent(event, decoratorsMatcher.group(GROUP_DECORATORS_TIME));
+            setTimeStampIfPresent(event, decoratorsMatcher.group(GROUP_DECORATORS_UPTIME));
+            return event;
         } else {
-            getLogger().warning("Failed to find heap details from string: \"" + memoryString + "\"");
+            getLogger().warning(String.format("Failed to parse line number %d (no match; line=\"%s\")", in.getLineNumber(), line));
+            return null;
+        }
+    }
+
+    private void setPause(AbstractGCEvent event, String pauseAsString) {
+        // TODO remove code duplication with AbstractDataReaderSun -> move to DataReaderTools
+        if (pauseAsString != null && pauseAsString.length() > 0) {
+            event.setPause(NumberParser.parseDouble(pauseAsString) / 1000);
+        }
+    }
+
+    private void setMemory(AbstractGCEvent event, Matcher matcher) {
+        // TODO remove code duplication with AbstractDataReaderSun -> move to DataReaderTools
+        event.setPreUsed(getDataReaderTools().getMemoryInKiloByte(
+                Integer.parseInt(matcher.group(GROUP_MEMORY_BEFORE)), matcher.group(GROUP_MEMORY_BEFORE_UNIT).charAt(0), matcher.group(GROUP_MEMORY)));
+        event.setPostUsed(getDataReaderTools().getMemoryInKiloByte(
+                Integer.parseInt(matcher.group(GROUP_MEMORY_AFTER)), matcher.group(GROUP_MEMORY_AFTER_UNIT).charAt(0), matcher.group(GROUP_MEMORY)));
+        event.setTotal(getDataReaderTools().getMemoryInKiloByte(
+                Integer.parseInt(matcher.group(GROUP_MEMORY_CURRENT_TOTAL)), matcher.group(GROUP_MEMORY_CURRENT_TOTAL_UNIT).charAt(0), matcher.group(GROUP_MEMORY)));
+        event.setExtendedType(event.getExtendedType());
+    }
+
+    private void setDateStampIfPresent(AbstractGCEvent<?> event, String dateStampAsString) {
+        // TODO remove code duplication with AbstractDataReaderSun -> move to DataReaderTools
+        if (dateStampAsString != null) {
+            ZonedDateTime dateTime = ZonedDateTime.parse(dateStampAsString, AbstractDataReaderSun.DATE_TIME_FORMATTER);
+            event.setDateStamp(dateTime);
+        }
+    }
+
+    private void setTimeStampIfPresent(AbstractGCEvent<?> event, String timeStampAsString) {
+        if (timeStampAsString != null && timeStampAsString.length() > 0) {
+            event.setTimestamp(NumberParser.parseDouble(timeStampAsString));
         }
     }
 
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
index eaa09e1a..b62d377e 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
@@ -577,19 +577,20 @@ public String toString() {
         // unified jvm logging g1 event types
         public static final Type UJL_G1_PAUSE_MIXED = new Type("Pause Mixed", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
         public static final Type UJL_G1_TO_SPACE_EXHAUSTED = new Type("To-space exhausted", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC);
-        public static final Type UJL_G1_CONCURRENT_CYCLE = new Type("Concurrent Cycle", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
+        public static final Type UJL_G1_CONCURRENT_CYCLE = new Type("Concurrent Cycle", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
         public static final Type UJL_G1_PAUSE_CLEANUP = new Type("Pause Cleanup", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
 
         // unified jvm logging shenandoah event types
+        // TODO rename events to start with UJL_...
         public static final Type SHEN_STW_INIT_MARK = new Type("Pause Init Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
-        public static final Type SHEN_STW_FINAL_MARK = new Type("Pause Final Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
+        public static final Type SHEN_STW_FINAL_MARK = new Type("Pause Final Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
         public static final Type SHEN_STW_INIT_UPDATE_REFS = new Type("Pause Init Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
-        public static final Type SHEN_STW_FINAL_UPDATE_REFS = new Type("Pause Final Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
-        public static final Type SHEN_CONCURRENT_CONC_MARK = new Type("Concurrent marking", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC);
-        public static final Type SHEN_CONCURRENT_CONC_EVAC = new Type("Concurrent evacuation", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC);
-        public static final Type SHEN_CONCURRENT_CONC_RESET_BITMAPS = new Type("Concurrent reset bitmaps", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC);
-        public static final Type SHEN_CONCURRENT_CONC_UPDATE_REFS = new Type("Concurrent update references", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC);
-        public static final Type SHEN_CONCURRENT_PRECLEANING = new Type("Concurrent precleaning", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC);
+        public static final Type SHEN_STW_FINAL_UPDATE_REFS = new Type("Pause Final Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type SHEN_CONCURRENT_CONC_MARK = new Type("Concurrent marking", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type SHEN_CONCURRENT_CONC_EVAC = new Type("Concurrent evacuation", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type SHEN_CONCURRENT_CONC_RESET_BITMAPS = new Type("Concurrent reset bitmaps", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type SHEN_CONCURRENT_CONC_UPDATE_REFS = new Type("Concurrent update references", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type SHEN_CONCURRENT_PRECLEANING = new Type("Concurrent precleaning", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
 
         // IBM Types
         // TODO: are scavenge always young only??
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
index 5f928039..7d842bcf 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
@@ -1,9 +1,20 @@
 package com.tagtraum.perf.gcviewer;
 
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
+import java.util.logging.Level;
+
+import com.tagtraum.perf.gcviewer.imp.DataReader;
+import com.tagtraum.perf.gcviewer.imp.DataReaderFactory;
+import com.tagtraum.perf.gcviewer.imp.TestLogHandler;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 
 /**
  * Helper class to support the unittests.
@@ -12,14 +23,27 @@
  * <p>created on: 22.05.2013</p>
  */
 public class UnittestHelper {
-    
-    public static final String FOLDER_HP = "hp";
-    public static final String FOLDER_IBM = "ibm";
-    public static final String FOLDER_JROCKIT = "jrockit";
-    public static final String FOLDER_OPENJDK = "openjdk";
-    public static final String FOLDER_OPENJDK_UJL = FOLDER_OPENJDK + File.separator + "unified-jvm-logging";
-    public static final String FOLDER_HTTP = "http";
-    
+
+    private static final String FOLDER_OPENJDK = "openjdk";
+    public enum FOLDER {
+        HP("hp"),
+        IBM("ibm"),
+        JROCKIT("jrockit"),
+        OPENJDK(FOLDER_OPENJDK),
+        OPENJDK_UJL(OPENJDK + File.separator + "unified-jvm-logging"),
+        HTTP("http");
+
+        private String folderName;
+        FOLDER(String folderName) {
+            this.folderName = folderName;
+        }
+
+        public String getFolderName() {
+            return folderName;
+        }
+
+    }
+
     /**
      * Load resource as stream if it is present somewhere in the classpath.
      * @param name Name of the resource
@@ -40,8 +64,8 @@ public static InputStream getResourceAsStream(String name) throws IOException {
      * 
      * @see #getResourceAsStream(String)
      */
-    public static InputStream getResourceAsStream(String folder, String name) throws IOException {
-        return getResourceAsStream(folder + File.separator + name);
+    public static InputStream getResourceAsStream(FOLDER folder, String name) throws IOException {
+        return getResourceAsStream(folder.getFolderName() + File.separator + name);
     }
 
     /**
@@ -64,8 +88,8 @@ public static URL getResource(String name) throws IOException {
      * 
      * @see #getResource(String)
      */
-    public static URL getResource(String folder, String name) throws IOException {
-        return getResource(folder + "/" + name);
+    public static URL getResource(FOLDER folder, String name) throws IOException {
+        return getResource(folder.getFolderName() + "/" + name);
     }
     
     /**
@@ -77,7 +101,7 @@ public static URL getResource(String folder, String name) throws IOException {
      * @throws IOException if resource could not be found
      * @see {@link #getResource(String)}
      */
-    public static String getResourceAsString(String folder, String name) throws IOException {
+    public static String getResourceAsString(FOLDER folder, String name) throws IOException {
         return getResource(folder, name).getFile();
     }
 
@@ -90,4 +114,30 @@ public static String getResourceAsString(String folder, String name) throws IOEx
     public static int toKiloBytes(long bytes) {
         return (int)Math.rint(bytes / (double)1024);
     }
+
+    /**
+     * Return GCModel from given input <code>fileName</code>.
+     *
+     * @param fileName file to be parsed
+     * @param folderName folder, where <code>fileName</code> can be found
+     * @param expectedDataReaderClass Expected DataReaderFactory class for the given fileName parameter
+     * @return GCModel model containing contents of parsed file
+     * @throws IOException thrown, if something went wrong reading the file
+     */
+    public static GCModel getGCModelFromLogFile(String fileName, FOLDER folderName, Class expectedDataReaderClass) throws IOException {
+        TestLogHandler handler = new TestLogHandler();
+        handler.setLevel(Level.WARNING);
+        GCResource gcResource = new GcResourceFile(fileName);
+        gcResource.getLogger().addHandler(handler);
+
+        try (InputStream in = getResourceAsStream(folderName, gcResource.getResourceName())) {
+            DataReader reader = new DataReaderFactory().getDataReader(gcResource, in);
+            assertThat("reader from factory", reader.getClass().getName(), is(expectedDataReaderClass.getName()));
+
+            GCModel model = reader.read();
+            assertThat("number of errors", handler.getCount(), is(0));
+            return model;
+        }
+    }
+
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GCModelSeriesLoaderImplTest.java b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GCModelSeriesLoaderImplTest.java
index cfa1dd59..10bfe6f3 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GCModelSeriesLoaderImplTest.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GCModelSeriesLoaderImplTest.java
@@ -1,19 +1,20 @@
 package com.tagtraum.perf.gcviewer.ctrl.impl;
 
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
+import java.util.ArrayList;
+
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.ctrl.GCModelLoader;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import java.util.ArrayList;
-
-import static org.hamcrest.CoreMatchers.notNullValue;
-import static org.junit.Assert.assertThat;
-
 public class GCModelSeriesLoaderImplTest {
     @Rule
     public ExpectedException expectedException = ExpectedException.none();
@@ -21,9 +22,9 @@ public class GCModelSeriesLoaderImplTest {
     @Test
     public void getGcResource() throws Exception {
         ArrayList<GCResource> gcResourceList = new ArrayList<>();
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
 
         GCModelLoader loader = new GCModelSeriesLoaderImpl(new GcResourceSeries(gcResourceList));
         assertThat(loader.getGcResource(), notNullValue());
@@ -38,9 +39,9 @@ public void GCModelSeriesLoaderImpl_ForEmptySeries() throws Exception {
     @Test
     public void loadGcModel() throws Exception {
         ArrayList<GCResource> gcResourceList = new ArrayList<>();
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
         GCModelSeriesLoaderImpl loader = new GCModelSeriesLoaderImpl(new GcResourceSeries(gcResourceList));
 
         assertThat(loader.loadGcModel(), notNullValue());
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GcSeriesLoaderTest.java b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GcSeriesLoaderTest.java
index d0da502c..a95280ca 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GcSeriesLoaderTest.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/GcSeriesLoaderTest.java
@@ -1,16 +1,7 @@
 package com.tagtraum.perf.gcviewer.ctrl.impl;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.imp.DataReaderException;
-import com.tagtraum.perf.gcviewer.imp.DataReaderFacade;
-import com.tagtraum.perf.gcviewer.model.*;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.ExpectedException;
-import org.junit.rules.TemporaryFolder;
-import org.junit.runner.RunWith;
-import org.mockito.runners.MockitoJUnitRunner;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 import java.io.File;
 import java.io.IOException;
@@ -25,8 +16,23 @@
 import java.util.List;
 import java.util.Map;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.MatcherAssert.assertThat;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.imp.DataReaderException;
+import com.tagtraum.perf.gcviewer.imp.DataReaderFacade;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
 
 @RunWith(MockitoJUnitRunner.class)
 public class GcSeriesLoaderTest {
@@ -182,6 +188,6 @@ private GCModel createModel(GCResource resource) throws DataReaderException {
     }
 
     private GcResourceFile getGcResource(String name) throws IOException {
-        return new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, name).getPath());
+        return new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, name).getPath());
     }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoader.java b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoader.java
index 5081d73d..196df4bc 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoader.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoader.java
@@ -1,15 +1,16 @@
 package com.tagtraum.perf.gcviewer.ctrl.impl;
 
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Test;
 
-import static org.hamcrest.Matchers.not;
-import static org.hamcrest.Matchers.notNullValue;
-import static org.junit.Assert.assertThat;
-
 /**
  * Unittest for {@link GCModelLoaderImpl}.
  * 
@@ -21,7 +22,7 @@ public class TestGCModelLoader {
     @Test
     public void loadExistingFile() throws Exception {
         GCResource gcResource = new GcResourceFile(
-                UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+                UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
         GCModelLoaderImpl loader = new GCModelLoaderImpl(gcResource);
         loader.execute();
         GCModel model = loader.get();
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoaderController.java b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoaderController.java
index 25a7ac82..f740b8fa 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoaderController.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/ctrl/impl/TestGCModelLoaderController.java
@@ -1,14 +1,8 @@
 package com.tagtraum.perf.gcviewer.ctrl.impl;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
-import com.tagtraum.perf.gcviewer.view.GCViewerGui;
-import com.tagtraum.perf.gcviewer.view.model.GCPreferences;
-import org.junit.Before;
-import org.junit.Test;
-import org.mockito.Mockito;
+import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
 
 import java.awt.datatransfer.DataFlavor;
 import java.awt.datatransfer.Transferable;
@@ -20,9 +14,16 @@
 import java.util.List;
 import java.util.stream.Collectors;
 
-import static org.hamcrest.Matchers.contains;
-import static org.hamcrest.Matchers.is;
-import static org.junit.Assert.assertThat;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
+import com.tagtraum.perf.gcviewer.view.GCViewerGui;
+import com.tagtraum.perf.gcviewer.view.model.GCPreferences;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mockito;
 
 /**
  * Unittest for main controller class of GCViewerGui ({@link GCModelLoaderControllerImpl}).
@@ -53,7 +54,7 @@ public void openStringFail() throws Exception {
     @Test
     public void openString() throws Exception {
         assertThat("number of gcdocuments before", controller.getGCViewerGui().getDesktopPane().getAllFrames().length, is(0));
-        controller.open(new GcResourceFile(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt")));
+        controller.open(new GcResourceFile(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt")));
         assertThat("number of gcdocuments after", controller.getGCViewerGui().getDesktopPane().getAllFrames().length, is(1));
 
     }
@@ -70,9 +71,9 @@ public void openAsSeries() throws Exception {
 
     private ArrayList<GCResource> getGcResourcesForSeries() throws IOException {
         ArrayList<GCResource> gcResourceList = new ArrayList<>();
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
-        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
+        gcResourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
         return gcResourceList;
     }
 
@@ -85,7 +86,7 @@ public void dropOnDesktopPane() throws Exception {
         assertThat("number of gcdocuments before", controller.getGCViewerGui().getDesktopPane().getAllFrames().length, is(0));
 
         List<File> fileList = new ArrayList<File>();
-        fileList.add(new File(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0G1_MarkStackFull.txt").getPath()));
+        fileList.add(new File(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_6_0G1_MarkStackFull.txt").getPath()));
 
         Transferable tr = Mockito.mock(Transferable.class);
         Mockito.when(tr.getTransferData(DataFlavor.javaFileListFlavor)).thenReturn(fileList);
@@ -103,7 +104,7 @@ public void dropOnDesktopPane() throws Exception {
     @Test
     public void open_File() throws Exception {
         File[] files = new File[1];
-        File file = new File(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+        File file = new File(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
         files[0] = file;
         controller.open(files);
         assertThat(getOpenResources(), contains(new GcResourceFile(file)));
@@ -111,7 +112,7 @@ public void open_File() throws Exception {
 
     @Test
     public void open_GcResourceFile() throws Exception {
-        GCResource resource = new GcResourceFile(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+        GCResource resource = new GcResourceFile(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
         controller.open(resource);
         assertThat(getOpenResources(), contains(resource));
     }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFacade.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFacade.java
index e5dc4625..a401ee5a 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFacade.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFacade.java
@@ -1,12 +1,10 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
-import org.junit.Before;
-import org.junit.Test;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -15,8 +13,14 @@
 import java.util.List;
 import java.util.logging.Level;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.*;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.model.GcResourceSeries;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Tests the implementation of {@link DataReaderFacade}.
@@ -28,7 +32,7 @@ public class TestDataReaderFacade {
 
     private static final String SAMPLE_GCLOG_SUN1_6_0 = "SampleSun1_6_0PrintHeapAtGC.txt";
     
-    private static final String PARENT_PATH = "src/test/resources/" + UnittestHelper.FOLDER_OPENJDK + "/";
+    private static final String PARENT_PATH = "src/test/resources/" + FOLDER.OPENJDK.getFolderName() + "/";
 
     private DataReaderFacade dataReaderFacade;
     
@@ -111,14 +115,14 @@ public void loadModelFileDoesntExists() throws Exception {
 
     @Test
     public void testLoadModel_forSeries() throws IOException, DataReaderException {
-        GCResource file1 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
-        GCResource file2 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath());
-        GCResource file3 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath());
-        GCResource file4 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part4.txt").getPath());
-        GCResource file5 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part5.txt").getPath());
-        GCResource file6 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part6.txt").getPath());
-        GCResource file7 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part7.txt").getPath());
-        GCResource expectedResult = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-ManuallyMerged.txt").getPath());
+        GCResource file1 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
+        GCResource file2 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath());
+        GCResource file3 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath());
+        GCResource file4 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part4.txt").getPath());
+        GCResource file5 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part5.txt").getPath());
+        GCResource file6 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part6.txt").getPath());
+        GCResource file7 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part7.txt").getPath());
+        GCResource expectedResult = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-ManuallyMerged.txt").getPath());
         GCModel expectedModel = dataReaderFacade.loadModel(expectedResult);
 
         List<GCResource> resources = new ArrayList<>();
@@ -137,14 +141,14 @@ public void testLoadModel_forSeries() throws IOException, DataReaderException {
 
     @Test
     public void testLoadModelFromSeries() throws IOException, DataReaderException {
-        GCResource file1 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
-        GCResource file2 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath());
-        GCResource file3 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath());
-        GCResource file4 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part4.txt").getPath());
-        GCResource file5 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part5.txt").getPath());
-        GCResource file6 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part6.txt").getPath());
-        GCResource file7 = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part7.txt").getPath());
-        GCResource expectedResult = new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-ManuallyMerged.txt").getPath());
+        GCResource file1 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
+        GCResource file2 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath());
+        GCResource file3 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath());
+        GCResource file4 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part4.txt").getPath());
+        GCResource file5 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part5.txt").getPath());
+        GCResource file6 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part6.txt").getPath());
+        GCResource file7 = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part7.txt").getPath());
+        GCResource expectedResult = new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-ManuallyMerged.txt").getPath());
         GCModel expectedModel = dataReaderFacade.loadModel(expectedResult);
 
         List<GCResource> resources = new ArrayList<>();
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFactory.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFactory.java
index b10b78fa..456c58de 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFactory.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderFactory.java
@@ -6,14 +6,14 @@
 import java.io.IOException;
 import java.io.InputStream;
 
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TestName;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-
 /**
  * Tests the logic of the {@link DataReaderFactory}
  *
@@ -29,15 +29,15 @@ public class TestDataReaderFactory {
     public TestName name = new TestName();
 
     private InputStream getInputStreamIBM(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
     }
 
     private InputStream getInputStreamJRockit(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_JROCKIT, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.JROCKIT, fileName);
     }
     
     private InputStream getInputStreamOpenJdk(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
     
     private void assertDataReader(
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_2.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_2.java
index b9dd2f6f..3d8ecc6a 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_2.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_2.java
@@ -4,11 +4,11 @@
 
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  *
@@ -21,7 +21,7 @@ public class TestDataReaderHPUX1_2 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleHP-UX1_3.txt";
-        InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_HP, fileName);
+        InputStream in = UnittestHelper.getResourceAsStream(FOLDER.HP, fileName);
         DataReader reader = new DataReaderHPUX1_2(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_4_1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_4_1.java
index abe0f5dd..bea1b30d 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_4_1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderHPUX1_4_1.java
@@ -10,11 +10,11 @@
 
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  *
@@ -27,7 +27,7 @@ public class TestDataReaderHPUX1_4_1 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleHP-UX1_4_1.txt";
-        final InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_HP, fileName);
+        final InputStream in = UnittestHelper.getResourceAsStream(FOLDER.HP, fileName);
         final DataReader reader = new DataReaderHPUX1_4_1(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_2_2.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_2_2.java
index 152c2f99..01498366 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_2_2.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_2_2.java
@@ -4,11 +4,11 @@
 
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  *
@@ -21,7 +21,7 @@ public class TestDataReaderIBM1_2_2 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleIBM1_2_2.txt";
-        InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        InputStream in = UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
         DataReader reader = new DataReaderIBM1_3_0(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_3_1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_3_1.java
index 36bf8c85..7b6e0560 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_3_1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_3_1.java
@@ -4,11 +4,11 @@
 
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  *
@@ -21,7 +21,7 @@ public class TestDataReaderIBM1_3_1 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleIBM1_3_1.txt";
-        InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        InputStream in = UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
         DataReader reader = new DataReaderIBM1_3_1(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_4_2.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_4_2.java
index e1a1dbe5..2525f513 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_4_2.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM1_4_2.java
@@ -10,13 +10,13 @@
 
 import java.io.InputStream;
 
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Ignore;
 import org.junit.Test;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-
 /**
  *
  * Date: Jan 30, 2002
@@ -29,7 +29,7 @@ public class TestDataReaderIBM1_4_2 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleIBM1_4_2.txt";
-        final InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        final InputStream in = UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
         final DataReader reader = new DataReaderIBM1_4_2(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMJ9_5_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMJ9_5_0.java
index 4b36fc94..41f56413 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMJ9_5_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMJ9_5_0.java
@@ -6,13 +6,13 @@
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Tests the implementation of {@link TestDataReaderIBMJ9_5_0} and {@link IBMJ9SAXHandler}. 
@@ -23,7 +23,7 @@
 public class TestDataReaderIBMJ9_5_0 {
 
     private InputStream getInputStream(String filename) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, filename);
+        return UnittestHelper.getResourceAsStream(FOLDER.IBM, filename);
     }
     
     private DataReader getDataReader(String fileName) throws UnsupportedEncodingException, IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R26.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R26.java
index f07a0080..1305f57e 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R26.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R26.java
@@ -10,6 +10,7 @@
 import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
@@ -21,7 +22,7 @@
  */
 public class TestDataReaderIBM_J9_R26 {
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R27.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R27.java
index d1f43457..8f53fb3f 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R27.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R27.java
@@ -10,6 +10,7 @@
 import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
@@ -23,7 +24,7 @@
 public class TestDataReaderIBM_J9_R27 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R28.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R28.java
index d93c1568..cc352209 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R28.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBM_J9_R28.java
@@ -11,6 +11,7 @@
 import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
@@ -25,7 +26,7 @@
 public class TestDataReaderIBM_J9_R28 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMi5OS1_4_2.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMi5OS1_4_2.java
index b92af1d5..51c6f760 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMi5OS1_4_2.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderIBMi5OS1_4_2.java
@@ -4,11 +4,11 @@
 
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 
 /**
@@ -22,7 +22,7 @@ public class TestDataReaderIBMi5OS1_4_2 {
     @Test
     public void testParse1() throws Exception {
         String fileName = "SampleIBMi5OS1_4_2.txt";
-        final InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_IBM, fileName);
+        final InputStream in = UnittestHelper.getResourceAsStream(FOLDER.IBM, fileName);
         final DataReader reader = new DataReaderIBMi5OS1_4_2(new GcResourceFile(fileName), in);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_4_2.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_4_2.java
index 52ae945a..faeab651 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_4_2.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_4_2.java
@@ -7,13 +7,13 @@
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Date: Jan 30, 2002
@@ -23,7 +23,7 @@
 public class TestDataReaderJRockit1_4_2 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_JROCKIT, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.JROCKIT, fileName);
     }
     
     private DataReader getDataReader1_4(String fileName) throws UnsupportedEncodingException, IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_5_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_5_0.java
index c82f67a9..b32e3ef6 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_5_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_5_0.java
@@ -17,15 +17,15 @@
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.math.DoubleData;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * <p>Test DataReaderJRockit1_5_0 implementation.</p>
@@ -37,7 +37,7 @@
 public class TestDataReaderJRockit1_5_0 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_JROCKIT, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.JROCKIT, fileName);
     }
     
     private DataReader getDataReader1_5(GCResource gcResource) throws UnsupportedEncodingException, IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_6_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_6_0.java
index 24498f3d..8c0d716b 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_6_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderJRockit1_6_0.java
@@ -11,14 +11,14 @@
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Tests for logs generated by JRockit 1.6 vm.
@@ -29,7 +29,7 @@
 public class TestDataReaderJRockit1_6_0 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_JROCKIT, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.JROCKIT, fileName);
     }
     
     private DataReader getDataReader(GCResource gcResource) throws UnsupportedEncodingException, IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_3_1_19.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_3_1_19.java
index dd562938..d06f29d2 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_3_1_19.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_3_1_19.java
@@ -4,13 +4,13 @@
 
 import java.io.InputStream;
 
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Ignore;
 import org.junit.Test;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-
 /**
  *
  * Date: Jan 30, 2002
@@ -25,7 +25,7 @@ public void testCMSPrintGCDetails() throws Exception {
     	// does not seem to be implemented at all
     	
         String fileName = "SampleSun1_3_1_19SunOS.txt";
-    	final InputStream in = UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+    	final InputStream in = UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
         final DataReader reader = new DataReaderSun1_3_1(new GcResourceFile(fileName), in, GcLogType.SUN1_3_1);
         GCModel model = reader.read();
         
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_4_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_4_0.java
index bd2b61d5..255f5fa3 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_4_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_4_0.java
@@ -1,8 +1,6 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.*;
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -10,7 +8,14 @@
 import java.util.Iterator;
 import java.util.logging.Level;
 
-import static org.junit.Assert.assertEquals;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Tests some cases for java 1.4 (using DataReaderSun1_6_0).
@@ -21,7 +26,7 @@
  */
 public class TestDataReaderSun1_4_0 {
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
    /**
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_5_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_5_0.java
index 254ebe2f..798bb3f4 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_5_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_5_0.java
@@ -6,11 +6,11 @@
 import java.io.IOException;
 import java.io.InputStream;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Tests some cases for java 1.5 (using DataReaderSun1_6_0).
@@ -22,7 +22,7 @@
 public class TestDataReaderSun1_5_0 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
     
     /**
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
index 95dadfea..09c1f5a2 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
@@ -1,11 +1,10 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import com.tagtraum.perf.gcviewer.model.GCEvent;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import org.junit.Test;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -14,16 +13,20 @@
 import java.time.format.DateTimeFormatter;
 import java.util.logging.Level;
 
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.is;
-import static org.junit.Assert.*;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 public class TestDataReaderSun1_6_0 {
 
     private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
     @Test
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
index eecc1132..2334b46e 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
@@ -1,11 +1,10 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import org.junit.Test;
+import static org.hamcrest.Matchers.closeTo;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -14,16 +13,20 @@
 import java.time.format.DateTimeFormatter;
 import java.util.logging.Level;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 public class TestDataReaderSun1_6_0G1 {
     
     private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
     
     /**
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
index 732a8454..f9cca111 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
@@ -13,9 +13,14 @@
 import java.util.Iterator;
 import java.util.logging.Level;
 
-import com.tagtraum.perf.gcviewer.model.*;
-import org.junit.Test;
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Tests for logs generated specifically by jdk 1.7.0.
@@ -28,7 +33,7 @@ public class TestDataReaderSun1_7_0 {
     private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0G1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0G1.java
index 1156d7f4..3bbb34be 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0G1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0G1.java
@@ -1,23 +1,32 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.math.DoubleData;
-import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
-import com.tagtraum.perf.gcviewer.model.*;
-import org.junit.Test;
+import static org.hamcrest.Matchers.closeTo;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.logging.Level;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.math.DoubleData;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import com.tagtraum.perf.gcviewer.model.ConcurrentGCEvent;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 public class TestDataReaderSun1_7_0G1 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
     private DataReader getDataReader(String fileName) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0.java
index a76a7477..95161823 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0.java
@@ -10,12 +10,12 @@
 import java.io.InputStream;
 import java.util.logging.Level;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Test logs generated specifically by java 1.8.
@@ -26,7 +26,7 @@
 public class TestDataReaderSun1_8_0 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0G1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0G1.java
index 943f66fd..ba75e7c7 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0G1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_8_0G1.java
@@ -11,13 +11,13 @@
 import java.io.UnsupportedEncodingException;
 import java.util.logging.Level;
 
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
-import org.junit.Test;
-
-import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import org.junit.Test;
 
 /**
  * Test logs generated specifically by JDK 1.8 G1 algorithm.
@@ -28,7 +28,7 @@
 public class TestDataReaderSun1_8_0G1 {
 
     private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK, fileName);
+        return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
     }
 
     private DataReader getDataReader(GCResource gcResource) throws UnsupportedEncodingException, IOException {
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
index 5f651890..903b01ba 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
@@ -6,23 +6,20 @@
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Test;
 
 /**
  * Tests unified jvm logging parser for cms gc events.
  */
 public class TestDataReaderUJLCMS {
-    private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK_UJL, fileName);
+    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
+        return UnittestHelper.getGCModelFromLogFile(fileName, FOLDER.OPENJDK_UJL, DataReaderUnifiedJvmLogging.class);
     }
 
     @Test
@@ -140,20 +137,4 @@ private void testMemoryPauseEvent(AbstractGCEvent<?> event,
         assertThat(eventName + " total heap", event.getTotal(), is(heapTotal));
     }
 
-    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
-        TestLogHandler handler = new TestLogHandler();
-        handler.setLevel(Level.WARNING);
-        GCResource gcResource = new GcResourceFile(fileName);
-        gcResource.getLogger().addHandler(handler);
-
-        try (InputStream in = getInputStream(gcResource.getResourceName())) {
-            DataReader reader = new DataReaderFactory().getDataReader(gcResource, in);
-            assertThat("reader from factory", reader.getClass().getCanonicalName(), is(DataReaderUnifiedJvmLogging.class.getCanonicalName()));
-
-            GCModel model = reader.read();
-            assertThat("model format", model.getFormat(), is(GCModel.Format.UNIFIED_JVM_LOGGING));
-            assertThat("number of errors", handler.getCount(), is(0));
-            return model;
-        }
-    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
index 2c9f918d..19f53ed0 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
@@ -6,23 +6,20 @@
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Test;
 
 /**
  * Tests unified jvm logging parser for cms gc events.
  */
 public class TestDataReaderUJLG1 {
-    private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK_UJL, fileName);
+    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
+        return UnittestHelper.getGCModelFromLogFile(fileName, FOLDER.OPENJDK_UJL, DataReaderUnifiedJvmLogging.class);
     }
 
     @Test
@@ -147,20 +144,4 @@ private void testMemoryPauseEvent(AbstractGCEvent<?> event,
         assertThat(eventName + " total heap", event.getTotal(), is(heapTotal));
     }
 
-    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
-        TestLogHandler handler = new TestLogHandler();
-        handler.setLevel(Level.WARNING);
-        GCResource gcResource = new GcResourceFile(fileName);
-        gcResource.getLogger().addHandler(handler);
-
-        try (InputStream in = getInputStream(gcResource.getResourceName())) {
-            DataReader reader = new DataReaderFactory().getDataReader(gcResource, in);
-            assertThat("reader from factory", reader.getClass().getCanonicalName(), is(DataReaderUnifiedJvmLogging.class.getCanonicalName()));
-
-            GCModel model = reader.read();
-            assertThat("model format", model.getFormat(), is(GCModel.Format.UNIFIED_JVM_LOGGING));
-            assertThat("number of errors", handler.getCount(), is(0));
-            return model;
-        }
-    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
index 93af518f..89c179dc 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
@@ -6,23 +6,20 @@
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Test;
 
 /**
  * Tests unified jvm logging parser for parallel gc events.
  */
 public class TestDataReaderUJLParallel {
-    private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK_UJL, fileName);
+    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
+        return UnittestHelper.getGCModelFromLogFile(fileName, FOLDER.OPENJDK_UJL, DataReaderUnifiedJvmLogging.class);
     }
 
     @Test
@@ -76,20 +73,4 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         assertThat("event3 timestamp", event3.getTimestamp(), closeTo(0.330, 0.0001));
     }
 
-    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
-        TestLogHandler handler = new TestLogHandler();
-        handler.setLevel(Level.WARNING);
-        GCResource gcResource = new GcResourceFile(fileName);
-        gcResource.getLogger().addHandler(handler);
-
-        try (InputStream in = getInputStream(gcResource.getResourceName())) {
-            DataReader reader = new DataReaderFactory().getDataReader(gcResource, in);
-            assertThat("reader from factory", reader.getClass().getName(), is(DataReaderUnifiedJvmLogging.class.getName()));
-
-            GCModel model = reader.read();
-            assertThat("model format", model.getFormat(), is(GCModel.Format.UNIFIED_JVM_LOGGING));
-            assertThat("number of errors", handler.getCount(), is(0));
-            return model;
-        }
-    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
index 41b10519..1140c69b 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
@@ -11,6 +11,7 @@
 import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
@@ -22,8 +23,8 @@
  * Tests unified jvm logging parser for serial gc events.
  */
 public class TestDataReaderUJLSerial {
-    private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK_UJL, fileName);
+    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
+        return UnittestHelper.getGCModelFromLogFile(fileName, FOLDER.OPENJDK_UJL, DataReaderUnifiedJvmLogging.class);
     }
 
     @Test
@@ -100,7 +101,7 @@ public void testParseUnknownLineFormat() throws Exception {
         GCModel model = reader.read();
 
         assertThat("number of warnings", handler.getCount(), is(1));
-        assertThat("warning message", handler.getLogRecords().get(0).getMessage(), startsWith("Failed to parse line number"));
+        assertThat("warning message", handler.getLogRecords().get(0).getMessage(), startsWith("Expected memory and pause in the end of line number"));
     }
 
     @Test
@@ -120,20 +121,4 @@ public void testParseUnknownGcType() throws Exception {
         assertThat("warning message", handler.getLogRecords().get(0).getMessage(), startsWith("Failed to parse gc event ("));
     }
 
-    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
-        TestLogHandler handler = new TestLogHandler();
-        handler.setLevel(Level.WARNING);
-        GCResource gcResource = new GcResourceFile(fileName);
-        gcResource.getLogger().addHandler(handler);
-
-        try (InputStream in = getInputStream(gcResource.getResourceName())) {
-            DataReader reader = new DataReaderFactory().getDataReader(gcResource, in);
-            assertThat("reader from factory", reader.getClass().getName(), is(DataReaderUnifiedJvmLogging.class.getName()));
-
-            GCModel model = reader.read();
-            assertThat("model format", model.getFormat(), is(GCModel.Format.UNIFIED_JVM_LOGGING));
-            assertThat("number of errors", handler.getCount(), is(0));
-            return model;
-        }
-    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
index 2aec73a1..f5afcf24 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
@@ -6,26 +6,23 @@
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.time.ZonedDateTime;
-import java.util.logging.Level;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.ConcurrentGCEvent;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
-import com.tagtraum.perf.gcviewer.model.GCResource;
-import com.tagtraum.perf.gcviewer.model.GcResourceFile;
 import org.junit.Test;
 
 /**
  * Created by Mart on 10/05/2017.
  */
 public class TestDataReaderUJLShenandoah {
-    private InputStream getInputStream(String fileName) throws IOException {
-        return UnittestHelper.getResourceAsStream(UnittestHelper.FOLDER_OPENJDK_UJL, fileName);
+    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
+        return UnittestHelper.getGCModelFromLogFile(fileName, FOLDER.OPENJDK_UJL, DataReaderUnifiedJvmLogging.class);
     }
 
     @Test
@@ -179,19 +176,4 @@ public void parseDateTimeStamps() throws Exception {
         assertThat("generation", event2.getGeneration(), is(AbstractGCEvent.Generation.TENURED));
     }
 
-
-    private GCModel getGCModelFromLogFile(String fileName) throws IOException {
-        TestLogHandler handler = new TestLogHandler();
-        handler.setLevel(Level.WARNING);
-        GCResource gcResource = new GcResourceFile(fileName);
-        gcResource.getLogger().addHandler(handler);
-
-        try (InputStream in = getInputStream(gcResource.getResourceName())) {
-            DataReader reader = new DataReaderUnifiedJvmLogging(gcResource, in);
-            GCModel model = reader.read();
-            assertThat("model format", model.getFormat(), is(GCModel.Format.UNIFIED_JVM_LOGGING));
-            assertThat("number of errors", handler.getCount(), is(0));
-            return model;
-        }
-    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/model/GcResourceSeriesTest.java b/src/test/java/com/tagtraum/perf/gcviewer/model/GcResourceSeriesTest.java
index 81951478..e4c477a7 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/model/GcResourceSeriesTest.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/model/GcResourceSeriesTest.java
@@ -1,19 +1,20 @@
 package com.tagtraum.perf.gcviewer.model;
 
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.ArrayList;
+import java.util.List;
+
 import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import java.util.ArrayList;
-import java.util.List;
-
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
 public class GcResourceSeriesTest {
     @Rule
     public ExpectedException expectedException = ExpectedException.none();
@@ -24,9 +25,9 @@ public class GcResourceSeriesTest {
     @Before
     public void setUp() throws Exception {
         resourceList = new ArrayList<>();
-        resourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
-        resourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
-        resourceList.add(new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
+        resourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath()));
+        resourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part2.txt").getPath()));
+        resourceList.add(new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part3.txt").getPath()));
 
         resourceSeries = new GcResourceSeries(resourceList);
     }
@@ -53,7 +54,7 @@ public void hasUnderlyingResourceChanged() throws Exception {
     @Test
     public void buildName() throws Exception {
         assertThat(GcResourceSeries.buildName(resourceList), is(
-                UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK).getPath() + "/" + "SampleSun1_8_0Series-Part1-3"));
+                UnittestHelper.getResource(FOLDER.OPENJDK.getFolderName()).getPath() + "/" + "SampleSun1_8_0Series-Part1-3"));
     }
 
     @Test
@@ -65,7 +66,7 @@ public void buildName_ForRotatedFile() throws Exception {
     public void buildName_WhenOnlyOneEntryExists() throws Exception {
         resourceList = new ArrayList<>();
         GcResourceFile gcResourceFile =
-                new GcResourceFile(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
+                new GcResourceFile(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_8_0Series-Part1.txt").getPath());
         resourceList.add(gcResourceFile);
         assertThat(GcResourceSeries.buildName(resourceList), is(gcResourceFile.getResourceName()));
     }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/model/TestGCModel.java b/src/test/java/com/tagtraum/perf/gcviewer/model/TestGCModel.java
index 0f716df7..b387ab4f 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/model/TestGCModel.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/model/TestGCModel.java
@@ -1,11 +1,8 @@
 package com.tagtraum.perf.gcviewer.model;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-import com.tagtraum.perf.gcviewer.imp.DataReaderException;
-import com.tagtraum.perf.gcviewer.imp.DataReaderFacade;
-import com.tagtraum.perf.gcviewer.math.DoubleData;
-import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
-import org.junit.Test;
+import static org.hamcrest.Matchers.closeTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
 import java.time.Instant;
@@ -15,9 +12,13 @@
 import java.time.temporal.ChronoUnit;
 import java.util.concurrent.ExecutionException;
 
-import static org.hamcrest.Matchers.closeTo;
-import static org.hamcrest.Matchers.is;
-import static org.junit.Assert.assertThat;
+import com.tagtraum.perf.gcviewer.UnittestHelper;
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
+import com.tagtraum.perf.gcviewer.imp.DataReaderException;
+import com.tagtraum.perf.gcviewer.imp.DataReaderFacade;
+import com.tagtraum.perf.gcviewer.math.DoubleData;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import org.junit.Test;
 
 /**
  * Specific tests for {@link GCModel} implementation.
@@ -43,7 +44,7 @@ public void fullGcInterval() throws Exception {
     @Test
     public void testEquals_ForIdenticalModels() throws IOException, ExecutionException, InterruptedException, DataReaderException {
         // load model twice, should be identical
-        GCResource gcResource = new GcResourceFile(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+        GCResource gcResource = new GcResourceFile(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
         DataReaderFacade dataReader = new DataReaderFacade();
 
         GCModel actual = dataReader.loadModel(gcResource);
@@ -59,7 +60,7 @@ public void testEquals_ForEmptyModels() {
     @Test
     public void testGetStartDate_WhenNeitherDateNorTimeStampsAreAvailable() throws Exception {
         GCModel model = new GCModel();
-        model.setURL(UnittestHelper.getResource(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+        model.setURL(UnittestHelper.getResource(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
 
         assertThat(model.getStartDate(), is(ZonedDateTime.ofInstant(Instant.ofEpochMilli(model.getLastModified()), ZoneId.systemDefault())));
     }
@@ -67,7 +68,7 @@ public void testGetStartDate_WhenNeitherDateNorTimeStampsAreAvailable() throws E
     @Test
     public void testGetStartDate_WhenDateStampsAreAvailable() throws Exception {
         DataReaderFacade dataReader = new DataReaderFacade();
-        GCModel model = dataReader.loadModel(new GcResourceFile(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMSAdaptiveSizePolicy.txt")));
+        GCModel model = dataReader.loadModel(new GcResourceFile(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMSAdaptiveSizePolicy.txt")));
 
         ZonedDateTime expectedTime = ZonedDateTime.of(2012, 4, 18, 14, 23, 59, 890_000_000, ZoneId.ofOffset("", ZoneOffset.ofHours(2)));
         assertThat(model.getStartDate(), is(expectedTime));
@@ -76,7 +77,7 @@ public void testGetStartDate_WhenDateStampsAreAvailable() throws Exception {
     @Test
     public void testGetStartDate_WhenNoDateButTimestampsAreAvailable() throws Exception {
         DataReaderFacade dataReader = new DataReaderFacade();
-        GcResourceFile gcResource = new GcResourceFile(UnittestHelper.getResourceAsString(UnittestHelper.FOLDER_OPENJDK, "SampleSun1_6_0CMS.txt"));
+        GcResourceFile gcResource = new GcResourceFile(UnittestHelper.getResourceAsString(FOLDER.OPENJDK, "SampleSun1_6_0CMS.txt"));
         GCModel model = dataReader.loadModel(gcResource);
 
         ZonedDateTime expectedTime = ZonedDateTime.ofInstant(Instant.ofEpochMilli(model.getLastModified()), ZoneId.systemDefault());
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java b/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
index afc43bb5..74d9ef56 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
@@ -24,16 +24,15 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
+import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import org.junit.Test;
 
-import com.tagtraum.perf.gcviewer.UnittestHelper;
-
 public class TestHttpUrlConnectionHelper {
 
     private static final String SAMPLE_GCLOG_SUN1_6_0 = "SampleSun1_6_0PrintHeapAtGC.txt";
     private static final String SAMPLE_GCLOG_SUN1_6_0_GZ = SAMPLE_GCLOG_SUN1_6_0 + ".gz";  
     
-    private static final String PARENT_PATH = "src/test/resources/" + UnittestHelper.FOLDER_OPENJDK + "/";
+    private static final String PARENT_PATH = "src/test/resources/" + FOLDER.OPENJDK + "/";
     private static final Charset UTF8 = StandardCharsets.UTF_8;
 
     private ByteArrayInputStream create404InputStream() {
diff --git a/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-cms-gc-defaults.txt b/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-cms-gc-defaults.txt
index a311bddb..4841a16a 100644
--- a/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-cms-gc-defaults.txt
+++ b/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-cms-gc-defaults.txt
@@ -11,7 +11,7 @@
 [0.714s][info][gc] GC(18) Concurrent Abortable Preclean 16.163ms
 [0.714s][info][gc] GC(18) Pause Remark 110M->110M(150M) 0.859ms
 [0.715s][info][gc] GC(18) Concurrent Sweep
-[0.715s][info][gc] GC(18) Concurrent Sweep 0.787ms
+[0.715s][info][gc] GC(18) Concurrent Sweep 1.111ms
 [0.715s][info][gc] GC(18) Concurrent Reset
 [0.716s][info][gc] GC(18) Concurrent Reset 0.134ms
 [0.799s][info][gc] GC(22) Pause Full (Allocation Failure) 125M->31M(150M) 9.775ms

From 1f485f315c09482a19c9e9361545a07ad6706163 Mon Sep 17 00:00:00 2001
From: chewiebug <jwu@gmx.ch>
Date: Sun, 25 Feb 2018 18:19:22 +0100
Subject: [PATCH 2/4] #155 support unified jvm logging format with tag "gc*"
 (level = trace) and decorations tags,level,time,uptime

(-Xlog:gc*=trace:file=<filename>:tags,level,time,uptime)
---
 README.md                                     |  10 +-
 .../gcviewer/imp/AbstractDataReaderSun.java   |   5 +-
 .../perf/gcviewer/imp/DataReaderTools.java    |  13 +-
 .../imp/DataReaderUnifiedJvmLogging.java      | 284 +++++++++++++++---
 .../perf/gcviewer/imp/IBMJ9SAXHandler.java    |   9 +-
 .../perf/gcviewer/model/AbstractGCEvent.java  | 159 +++++++---
 .../gcviewer/model/ConcurrentGCEvent.java     |   8 +
 .../tagtraum/perf/gcviewer/model/GCEvent.java |  52 +++-
 .../perf/gcviewer/model/GCEventUJL.java       |  27 ++
 .../perf/gcviewer/util/DateHelper.java        |  21 ++
 .../perf/gcviewer/UnittestHelper.java         |  35 +++
 .../gcviewer/imp/TestDataReaderSun1_6_0.java  |   3 +-
 .../imp/TestDataReaderSun1_6_0G1.java         |   3 +-
 .../gcviewer/imp/TestDataReaderSun1_7_0.java  |  15 +-
 .../gcviewer/imp/TestDataReaderUJLCMS.java    |  73 ++---
 .../gcviewer/imp/TestDataReaderUJLG1.java     | 132 +++++---
 .../imp/TestDataReaderUJLParallel.java        |  67 +++--
 .../gcviewer/imp/TestDataReaderUJLSerial.java |  10 +-
 .../imp/TestDataReaderUJLShenandoah.java      |  13 +-
 .../perf/gcviewer/model/TestGcEvent.java      |  21 +-
 ...ll,safepoint,os+cpu-to-space-exhausted.txt |  15 +
 21 files changed, 742 insertions(+), 233 deletions(-)
 create mode 100644 src/main/java/com/tagtraum/perf/gcviewer/model/GCEventUJL.java
 create mode 100644 src/main/java/com/tagtraum/perf/gcviewer/util/DateHelper.java
 create mode 100644 src/test/resources/openjdk/unified-jvm-logging/sample-ujl-g1-gc-all,safepoint,os+cpu-to-space-exhausted.txt

diff --git a/README.md b/README.md
index d945a77d..c1f73274 100644
--- a/README.md
+++ b/README.md
@@ -19,9 +19,11 @@ When logfile rotation (-XX:+UseGCLogFileRotation) is enabled, the logfiles can b
 
 Supported verbose:gc formats are:
 
-- partial support for OpenJDK 9 unified logging format -Xlog:gc:<file>
-  - no heap information is evaluated, but all events with tag "gc" only should be recognised
-  - required decorations: tags,uptime (others will be ignored or parser might fail)
+- some support for OpenJDK 9 unified logging format -Xlog:gc:<file>, the following configurations will work
+  - -Xlog:gc:file="path-to-file" (uses defaults)
+  - -Xlog:gc=info:file="path-to-file":tags,uptime,level (minimum configuration needed)
+  - -Xlog:gc*=trace:file="path-to-file":tags,time,uptime,level
+    (maximum configuration supported, additional tags ok, but ignored; additional decorations will break parsing)
 - Oracle JDK 1.8 -Xloggc:<file> [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
 - Sun / Oracle JDK 1.7 with option -Xloggc:<file> [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
 - Sun / Oracle JDK 1.6 with option -Xloggc:<file> [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
@@ -32,7 +34,7 @@ Supported verbose:gc formats are:
 - HP-UX JDK 1.2/1.3/1.4.x with the option -Xverbosegc
 - BEA JRockit 1.4.2/1.5/1.6 with the option -verbose:memory [-Xverbose:gcpause,gcreport] [-Xverbosetimestamp]
 
-Best results are achieved with: -Xloggc:<file> -XX:+PrintGCDetails -XX:+PrintGCDateStamps.
+Best results for non unified gc logging Oracle JDKs are achieved with: -Xloggc:<file> -XX:+PrintGCDetails -XX:+PrintGCDateStamps.
 A few other options are supported, but most of the information generated is ignored by GCViewer
 (the javadoc introduction of 
 https://github.com/chewiebug/GCViewer/blob/master/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderSun1_6_0.java
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
index 67416505..b7889dbe 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
@@ -5,7 +5,6 @@
 import java.io.LineNumberReader;
 import java.io.UnsupportedEncodingException;
 import java.time.ZonedDateTime;
-import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeParseException;
 import java.time.temporal.ChronoUnit;
 import java.util.LinkedList;
@@ -17,6 +16,7 @@
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.GcPattern;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import com.tagtraum.perf.gcviewer.util.NumberParser;
 import com.tagtraum.perf.gcviewer.util.ParseInformation;
 
@@ -31,7 +31,6 @@
  */
 public abstract class AbstractDataReaderSun extends AbstractDataReader {
 
-    public static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
     private static final int LENGTH_OF_DATESTAMP = 29;
 
     private static final String CMS_PRINT_PROMOTION_FAILURE = "promotion failure size";
@@ -433,7 +432,7 @@ protected ZonedDateTime parseDatestamp(String line, ParseInformation pos) throws
         if (nextIsDatestamp(line, pos)) {
             try {
                 zonedDateTime = ZonedDateTime.parse(line.substring(pos.getIndex(), pos.getIndex() + LENGTH_OF_DATESTAMP - 1),
-                        DATE_TIME_FORMATTER);
+                        DateHelper.DATE_TIME_FORMATTER);
                 pos.setIndex(pos.getIndex() + LENGTH_OF_DATESTAMP);
                 if (pos.getFirstDateStamp() == null) {
                     pos.setFirstDateStamp(zonedDateTime);
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
index 29f2c50b..58ef64e3 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderTools.java
@@ -78,9 +78,7 @@ public ExtendedType parseType(String typeString) throws UnknownGcTypeException {
     public ExtendedType parseTypeWithCause(String typeName) {
         typeName = typeName.trim();
         ExtendedType extendedType = null;
-        String lookupTypeName = typeName.endsWith("--")
-                ? typeName.substring(0, typeName.length()-2)
-                : typeName;
+        String lookupTypeName = getLookupTypeName(typeName);
         AbstractGCEvent.Type gcType = AbstractGCEvent.Type.lookup(lookupTypeName);
         // the gcType may be null because there was a PrintGCCause flag enabled - if so, reparse it with the first paren set stripped
         if (gcType == null) {
@@ -98,5 +96,14 @@ public ExtendedType parseTypeWithCause(String typeName) {
         return extendedType;
     }
 
+    private String getLookupTypeName(String typeName) {
+        typeName = typeName.endsWith(":")
+                ? typeName.substring(0, typeName.length()-1)
+                : typeName;
+        return typeName.endsWith("--")
+                    ? typeName.substring(0, typeName.length()-2)
+                    : typeName;
+    }
+
 
 }
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
index b05fafbb..48f2e0ec 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderUnifiedJvmLogging.java
@@ -3,10 +3,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
-import java.time.ZonedDateTime;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
-import java.util.Objects;
+import java.util.Map;
 import java.util.logging.Level;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -15,19 +15,25 @@
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Concurrency;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.GcPattern;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.ConcurrentGCEvent;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
+import com.tagtraum.perf.gcviewer.model.GCEventUJL;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import com.tagtraum.perf.gcviewer.util.NumberParser;
 
 /**
  * DataReaderUnifiedJvmLogging can parse all gc events of unified jvm logs with default decorations.
  * <p>
  * Currently needs the "gc" selector with "info" level and "uptime,level,tags" decorators (Java 9.0.1).
+ * Also supports "gc*" selector with "trace" level and "time,uptime,level,tags" decorators, but will ignore some of
+ * the debug and all trace level info (evaluates the following tags: "gc", "gc,start", "gc,heap", "gc,metaspace".
  * <ul>
- * <li>minimum configuration with defaults: <code>-Xlog:gc:file="path-to-file"</code></li>
- * <li>configuration with tags + decorations: <code>-Xlog:gc=info:file="path-to-file":tags,uptime,level</code></li>
+ * <li>minimum configuration with defaults supported: <code>-Xlog:gc:file="path-to-file"</code></li>
+ * <li>explicit minimum configuration needed: <code>-Xlog:gc=info:file="path-to-file":tags,uptime,level</code></li>
+ * <li>maximum detail configuration this parser is able to work with: <code>-Xlog:gc*=trace:file="path-to-file":tags,time,uptime,level</code></li>
  * </ul>
  * Only processes the following information format for Serial, Parallel, CMS, G1 and Shenandoah algorithms, everything else is ignored:
  * <pre>
@@ -52,7 +58,7 @@ public class DataReaderUnifiedJvmLogging extends AbstractDataReader {
     // Regex: ^(?:\[(?<time>[0-9-T:.+]*)])?(?:\[(?<uptime>[^s]*)s])?\[(?<level>[^]]+)]\[(?:(?<tags>[^] ]+)[ ]*)][ ]GC\((?<gcnumber>[0-9]+)\)[ ](?<type>([-.a-zA-Z ()]+|[a-zA-Z1 ()]+))(?:(?:[ ](?<tail>[0-9]{1}.*))|$)
     //   note for the <type> part: easiest would have been to use [^0-9]+, but the G1 events don't fit there, because of the number in their name
     private static final Pattern PATTERN_DECORATORS = Pattern.compile(
-            "^(?:\\[(?<time>[0-9-T:.+]*)])?(?:\\[(?<uptime>[^s]*)s])?\\[(?<level>[^]]+)]\\[(?:(?<tags>[^] ]+)[ ]*)][ ]GC\\((?<gcnumber>[0-9]+)\\)[ ](?<type>[-.a-zA-Z ()]+|[a-zA-Z1 ()]+)(?:(?:[ ](?<tail>[0-9]{1}.*))|$)"
+            "^(?:\\[(?<time>[0-9-T:.+]*)])?(?:\\[(?<uptime>[^s]*)s])?\\[(?<level>[^]]+)]\\[(?:(?<tags>[^] ]+)[ ]*)][ ]GC\\((?<gcnumber>[0-9]+)\\)[ ](?<type>[-.a-zA-Z: ()]+|[a-zA-Z1 ()]+)(?:(?:[ ](?<tail>[0-9]{1}.*))|$)"
     );
     private static final String GROUP_DECORATORS_TIME = "time";
     private static final String GROUP_DECORATORS_UPTIME = "uptime";
@@ -62,13 +68,27 @@ public class DataReaderUnifiedJvmLogging extends AbstractDataReader {
     private static final String GROUP_DECORATORS_GC_TYPE = "type";
     private static final String GROUP_DECORATORS_TAIL = "tail";
 
+    private static final Pattern PATTERN_HEAP_REGION_SIZE = Pattern.compile("^Heap region size: ([0-9]+)M$");
+    private static final int GROUP_HEAP_REGION_SIZE = 1;
+
     private static final String PATTERN_PAUSE_STRING = "([0-9]+[.,][0-9]+)ms";
+    private static final String PATTERN_MEMORY_STRING = "(([0-9]+)([BKMG])->([0-9]+)([BKMG])\\(([0-9]+)([BKMG])\\))";
+
     // Input: 1.070ms
     // Group 1: 1.070
     private static final Pattern PATTERN_PAUSE = Pattern.compile("^" + PATTERN_PAUSE_STRING);
 
     private static final int GROUP_PAUSE = 1;
 
+    // Input: 4848M->4855M(4998M)
+    // Group 1: 4848
+    // Group 2: M
+    // Group 3: 4855
+    // Group 4: M
+    // Group 5: 4998
+    // Group 6: M
+    private static final Pattern PATTERN_MEMORY = Pattern.compile("^" + PATTERN_MEMORY_STRING);
+
     // Input: 4848M->4855M(4998M) 2.872ms
     // Group 1: 4848
     // Group 2: M
@@ -76,8 +96,8 @@ public class DataReaderUnifiedJvmLogging extends AbstractDataReader {
     // Group 4: M
     // Group 5: 4998
     // Group 6: M
-    // Group 7: 1.070
-    private static final Pattern PATTERN_MEMORY_PAUSE = Pattern.compile("^(([0-9]+)([BKMG])->([0-9]+)([BKMG])\\(([0-9]+)([BKMG])\\)) " + PATTERN_PAUSE_STRING);
+    // Group 7: 1.070 (optional group)
+    private static final Pattern PATTERN_MEMORY_PAUSE = Pattern.compile("^" + PATTERN_MEMORY_STRING + "(?:(?:[ ]" + PATTERN_PAUSE_STRING + ")|$)");
 
     private static final int GROUP_MEMORY = 1;
     private static final int GROUP_MEMORY_BEFORE = 2;
@@ -88,12 +108,27 @@ public class DataReaderUnifiedJvmLogging extends AbstractDataReader {
     private static final int GROUP_MEMORY_CURRENT_TOTAL_UNIT = 7;
     private static final int GROUP_MEMORY_PAUSE = 8;
 
+    // Input: 7->3(2)
+    // Group 1: 7
+    // Group 2: 3
+    // Group 3: 2 (optional group)
+    private static final Pattern PATTERN_REGION = Pattern.compile("^([0-9]+)->([0-9]+)(?:\\(([0-9]+)\\))?");
+
+    private static final int GROUP_REGION_BEFORE = 1;
+    private static final int GROUP_REGION_AFTER = 2;
+    private static final int GROUP_REGION_TOTAL = 3;
+
+    private static final String TAG_GC = "gc";
+    private static final String TAG_GC_START = "gc,start";
+    private static final String TAG_GC_HEAP = "gc,heap";
+    private static final String TAG_GC_METASPACE = "gc,metaspace";
+
     /** list of strings, that must be part of the gc log line to be considered for parsing */
-    private static final List<String> INCLUDE_STRINGS = Arrays.asList("[gc ", "[gc]");
+    private static final List<String> INCLUDE_STRINGS = Arrays.asList("[gc ", "[gc]", "[" + TAG_GC_START, "[" + TAG_GC_HEAP, "[" + TAG_GC_METASPACE);
     /** list of strings, that target gc log lines, that - although part of INCLUDE_STRINGS - are not considered a gc event */
-    private static final List<String> EXCLUDE_STRINGS = Arrays.asList("Cancelling concurrent GC", "[debug", "[trace");
+    private static final List<String> EXCLUDE_STRINGS = Arrays.asList("Cancelling concurrent GC", "[debug", "[trace", "gc,heap,coops", "gc,heap,exit");
     /** list of strings, that are gc log lines, but not a gc event -&gt; should be logged only */
-    private static final List<String> LOG_ONLY_STRINGS = Arrays.asList("Using");
+    private static final List<String> LOG_ONLY_STRINGS = Arrays.asList("Using", "Heap region size");
 
 
     protected DataReaderUnifiedJvmLogging(GCResource gcResource, InputStream in) throws UnsupportedEncodingException {
@@ -105,14 +140,19 @@ public GCModel read() throws IOException {
         getLogger().info("Reading Oracle / OpenJDK unified jvm logging format...");
 
         try {
+            // some information shared accross several lines of parsing...
+            Map<String, AbstractGCEvent<?>> partialEventsMap = new HashMap<>();
+            Map<String, Object> infoMap = new HashMap<>();
+
             GCModel model = new GCModel();
             model.setFormat(GCModel.Format.UNIFIED_JVM_LOGGING);
 
             Stream<String> lines = in.lines();
-            lines.filter(this::lineContainsParseableEvent)
+            lines.map(line -> new ParseContext(line, partialEventsMap, infoMap))
+                    .filter(this::lineContainsParseableEvent)
                     .map(this::parseEvent)
-                    .filter(Objects::nonNull)
-                    .forEach(model::add);
+                    .filter(context -> context.getCurrentEvent() != null)
+                    .forEach(context -> model.add(context.getCurrentEvent()));
 
             return model;
         } finally {
@@ -120,48 +160,129 @@ public GCModel read() throws IOException {
         }
     }
 
-    private AbstractGCEvent<?> parseEvent(String line) {
+    private ParseContext parseEvent(ParseContext context) {
         AbstractGCEvent<?> event = null;
 
-        Matcher decoratorsMatcher = PATTERN_DECORATORS.matcher(line);
+        Matcher decoratorsMatcher = PATTERN_DECORATORS.matcher(context.getLine());
         try {
-            event = createGcEventWithStandardDecorators(decoratorsMatcher, line);
+            event = createGcEventWithStandardDecorators(decoratorsMatcher, context.getLine());
             if (event != null) {
+                String tags = decoratorsMatcher.group(GROUP_DECORATORS_TAGS);
                 String tail = decoratorsMatcher.group(GROUP_DECORATORS_TAIL);
-                if (event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE)) {
-                    handleGcPauseTail(line, event, tail);
-                } else if (event.getExtendedType().getPattern().equals(GcPattern.GC_MEMORY_PAUSE)) {
-                    handleGcMemoryPauseTail(line, event, tail);
-                } else if (event.getExtendedType().getPattern().equals(GcPattern.GC) || event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE_DURATION)) {
-                    handleGcTail(line, tail);
-                }
+                event = handleTail(context, event, tags, tail);
             }
         } catch (UnknownGcTypeException | NumberFormatException e) {
             // prevent incomplete event from being added to the GCModel
             event = null;
-            getLogger().warning(String.format("Failed to parse gc event (%s) on line number %d (line=\"%s\")", e.toString(), in.getLineNumber(), line));
+            getLogger().warning(String.format("Failed to parse gc event (%s) on line number %d (line=\"%s\")", e.toString(), in.getLineNumber(), context.getLine()));
+        }
+
+        context.setCurrentEvent(event);
+        return context;
+    }
+
+    private AbstractGCEvent<?> handleTail(ParseContext context, AbstractGCEvent<?> event, String tags, String tail) {
+        AbstractGCEvent<?> returnEvent = event;
+        switch (tags) {
+            case TAG_GC_START:
+                // here, the gc type is known, and the partial events will need to be added later
+                context.getPartialEventsMap().put(event.getNumber() + "", event);
+                returnEvent = null;
+                break;
+            case TAG_GC_HEAP:
+                // fallthrough -> same handling as for METASPACE event
+            case TAG_GC_METASPACE:
+                event = parseTail(context, event, tail);
+                // the UJL "Old" event occurs often after the next STW events have taken place; ignore it for now
+                //   size after concurrent collection will be calculated by GCModel#add()
+                if (!event.getExtendedType().getType().equals(Type.UJL_CMS_CONCURRENT_OLD)) {
+                    updateEventDetails(context, event);
+                }
+                returnEvent = null;
+                break;
+            case TAG_GC:
+                AbstractGCEvent<?> parentEvent = context.getPartialEventsMap().get(event.getNumber() + "");
+                if (parentEvent != null) {
+                    if (parentEvent.getExtendedType().equals(returnEvent.getExtendedType())) {
+                        // date- and timestamp are always end of event -> adjust the parent event
+                        parentEvent.setDateStamp(event.getDatestamp());
+                        parentEvent.setTimestamp(event.getTimestamp());
+                        returnEvent = parseTail(context, parentEvent, tail);
+                        context.partialEventsMap.remove(event.getNumber() + "");
+                    } else {
+                        // more detail information is provided for the parent event
+                        updateEventDetails(context, returnEvent);
+                        returnEvent = null;
+                    }
+                } else {
+                    returnEvent = parseTail(context, event, tail);
+                }
+                break;
+            default:
+                getLogger().warning(String.format("Unexpected tail present in the end of line number %d (tail=\"%s\"; line=\"%s\")", in.getLineNumber(), tail, context.getLine()));
+        }
+
+        return returnEvent;
+    }
+
+    private void updateEventDetails(ParseContext context, AbstractGCEvent<?> event) {
+        AbstractGCEvent<?> parentEvent = context.getPartialEventsMap().get(event.getNumber() + "");
+        if (parentEvent == null) {
+            getLogger().warning(String.format("Didn't find parent event for partial event %s (line number %d, line=\"%s\"", event.toString(), in.getLineNumber(), context.getLine()));
+        } else {
+            if (parentEvent instanceof GCEvent) {
+                ((GCEvent)parentEvent).add((GCEvent)event);
+            } else {
+                getLogger().warning(String.format("Parent (%s) event for %s should be GCEvent (line number %d, line=\"%s\"", parentEvent.toString(), event.toString(), in.getLineNumber(), context.getLine()));
+            }
+        }
+    }
+
+    private AbstractGCEvent<?> parseTail(ParseContext context, AbstractGCEvent<?> event, String tail) {
+        if (event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE)) {
+            parseGcPauseTail(context, event, tail);
+        } else if (event.getExtendedType().getPattern().equals(GcPattern.GC_MEMORY)) {
+            parseGcMemoryTail(context, event, tail);
+        } else if (event.getExtendedType().getPattern().equals(GcPattern.GC_REGION)) {
+            parseGcRegionTail(context, event, tail);
+        } else if (event.getExtendedType().getPattern().equals(GcPattern.GC_MEMORY_PAUSE)) {
+            parseGcMemoryPauseTail(context, event, tail);
+        } else if (event.getExtendedType().getPattern().equals(GcPattern.GC) || event.getExtendedType().getPattern().equals(GcPattern.GC_PAUSE_DURATION)) {
+            parseGcTail(context, tail);
         }
 
         return event;
     }
 
-    private void handleGcTail(String line, String tail) {
+    private void parseGcTail(ParseContext context, String tail) {
         if (!(tail == null)) {
-            getLogger().warning(String.format("Unexpected tail present in the end of line number %d (expected nothing to be present, tail=\"%s\"; line=\"%s\")", in.getLineNumber(), tail, line));
+            getLogger().warning(String.format("Unexpected tail present in the end of line number %d (expected nothing to be present, tail=\"%s\"; line=\"%s\")", in.getLineNumber(), tail, context.getLine()));
+        }
+    }
+
+    private void parseGcMemoryTail(ParseContext context, AbstractGCEvent<?> event, String tail) {
+        Matcher memoryMatcher = tail != null ? PATTERN_MEMORY.matcher(tail) : null;
+        if (memoryMatcher != null && memoryMatcher.find()) {
+            setMemory(event, memoryMatcher);
+        } else {
+            getLogger().warning(String.format("Expected only memory in the end of line number %d (line=\"%s\")", in.getLineNumber(), context.getLine()));
         }
     }
 
-    private void handleGcMemoryPauseTail(String line, AbstractGCEvent<?> event, String tail) {
-        Matcher memoryPauseMatcher = PATTERN_MEMORY_PAUSE.matcher(tail);
-        if (memoryPauseMatcher.find()) {
+    private void parseGcMemoryPauseTail(ParseContext context, AbstractGCEvent<?> event, String tail) {
+        Matcher memoryPauseMatcher = tail != null ? PATTERN_MEMORY_PAUSE.matcher(tail) : null;
+        if (memoryPauseMatcher != null && memoryPauseMatcher.find()) {
             setPause(event, memoryPauseMatcher.group(GROUP_MEMORY_PAUSE));
-            setMemory(event, memoryPauseMatcher);
+            if (!hasMemory(event)) {
+                // if the event already has detail memory information, there is no need to add the high level one as well
+                setMemory(event, memoryPauseMatcher);
+            }
         } else {
-            getLogger().warning(String.format("Expected memory and pause in the end of line number %d (line=\"%s\")", in.getLineNumber(), line));
+            getLogger().warning(String.format("Expected memory and pause in the end of line number %d (line=\"%s\")", in.getLineNumber(), context.getLine()));
         }
     }
 
-    private void handleGcPauseTail(String line, AbstractGCEvent<?> event, String tail) {
+    private void parseGcPauseTail(ParseContext context, AbstractGCEvent<?> event, String tail) {
         // G1 and CMS algorithms have "gc" tagged concurrent events, that are actually the start of an event
         // (I'd expect them to be tagged "gc,start", as this seems to be the case for the Shenandoah algorithm)
         // G1: Concurrent Cycle (without pause -> start of event; with pause -> end of event)
@@ -173,8 +294,27 @@ private void handleGcPauseTail(String line, AbstractGCEvent<?> event, String tai
             if (pauseMatcher.find()) {
                 setPause(event, pauseMatcher.group(GROUP_PAUSE));
             } else {
-                getLogger().warning(String.format("Expected only pause in the end of line number %d  (line=\"%s\")", in.getLineNumber(), line));
+                getLogger().warning(String.format("Expected only pause in the end of line number %d  (line=\"%s\")", in.getLineNumber(), context.getLine()));
+            }
+        }
+    }
+
+    private void parseGcRegionTail(ParseContext context, AbstractGCEvent<?> event, String tail) {
+        Matcher regionMatcher = tail != null ? PATTERN_REGION.matcher(tail) : null;
+        if (regionMatcher != null && regionMatcher.find()) {
+            int regionSize = context.getRegionSize();
+            // if the event has regions, but the regionSize is unknown, at the moment, I don't know, how to calculate the size
+            // -> store 0 for the size
+            // this happens, whenever a G1 log file is parsed and the line
+            // [0.018s][info][gc,heap] Heap region size: 1M
+            // is missing (only part of log present)
+            event.setPreUsed(Integer.parseInt(regionMatcher.group(GROUP_REGION_BEFORE)) * regionSize * 1024);
+            event.setPostUsed(Integer.parseInt(regionMatcher.group(GROUP_REGION_AFTER)) * regionSize * 1024);
+            if (regionMatcher.group(GROUP_REGION_TOTAL) != null) {
+                event.setTotal(Integer.parseInt(regionMatcher.group(GROUP_REGION_TOTAL)) * regionSize * 1024);
             }
+        } else {
+            getLogger().warning(String.format("Expected region information in the end of line number %d (line=\"%s\")", in.getLineNumber(), context.getLine()));
         }
     }
 
@@ -189,8 +329,9 @@ private AbstractGCEvent<?> createGcEventWithStandardDecorators(Matcher decorator
         if (decoratorsMatcher.find()) {
             AbstractGCEvent.ExtendedType type = getDataReaderTools().parseType(decoratorsMatcher.group(GROUP_DECORATORS_GC_TYPE));
 
-            AbstractGCEvent<?> event = type.getConcurrency().equals(Concurrency.CONCURRENT) ? new ConcurrentGCEvent() : new GCEvent();
+            AbstractGCEvent<?> event = type.getConcurrency().equals(Concurrency.CONCURRENT) ? new ConcurrentGCEvent() : new GCEventUJL();
             event.setExtendedType(type);
+            event.setNumber(Integer.parseInt(decoratorsMatcher.group(GROUP_DECORATORS_GC_NUMBER)));
             setDateStampIfPresent(event, decoratorsMatcher.group(GROUP_DECORATORS_TIME));
             setTimeStampIfPresent(event, decoratorsMatcher.group(GROUP_DECORATORS_UPTIME));
             return event;
@@ -207,6 +348,10 @@ private void setPause(AbstractGCEvent event, String pauseAsString) {
         }
     }
 
+    private boolean hasMemory(AbstractGCEvent<?> event) {
+        return event.getTotal() > 0;
+    }
+
     private void setMemory(AbstractGCEvent event, Matcher matcher) {
         // TODO remove code duplication with AbstractDataReaderSun -> move to DataReaderTools
         event.setPreUsed(getDataReaderTools().getMemoryInKiloByte(
@@ -215,14 +360,12 @@ private void setMemory(AbstractGCEvent event, Matcher matcher) {
                 Integer.parseInt(matcher.group(GROUP_MEMORY_AFTER)), matcher.group(GROUP_MEMORY_AFTER_UNIT).charAt(0), matcher.group(GROUP_MEMORY)));
         event.setTotal(getDataReaderTools().getMemoryInKiloByte(
                 Integer.parseInt(matcher.group(GROUP_MEMORY_CURRENT_TOTAL)), matcher.group(GROUP_MEMORY_CURRENT_TOTAL_UNIT).charAt(0), matcher.group(GROUP_MEMORY)));
-        event.setExtendedType(event.getExtendedType());
     }
 
     private void setDateStampIfPresent(AbstractGCEvent<?> event, String dateStampAsString) {
         // TODO remove code duplication with AbstractDataReaderSun -> move to DataReaderTools
         if (dateStampAsString != null) {
-            ZonedDateTime dateTime = ZonedDateTime.parse(dateStampAsString, AbstractDataReaderSun.DATE_TIME_FORMATTER);
-            event.setDateStamp(dateTime);
+            event.setDateStamp(DateHelper.parseDate(dateStampAsString));
         }
     }
 
@@ -244,10 +387,12 @@ private boolean isLogOnlyLine(String line) {
         return LOG_ONLY_STRINGS.stream().anyMatch(line::contains);
     }
 
-    private boolean lineContainsParseableEvent(String line) {
-        if (isCandidateForParseableEvent(line) && !isExcludedLine(line)) {
-            if (isLogOnlyLine(line)) {
-                getLogger().info(line.substring(line.lastIndexOf("]")+1));
+    private boolean lineContainsParseableEvent(ParseContext context) {
+        if (isCandidateForParseableEvent(context.getLine()) && !isExcludedLine(context.getLine())) {
+            if (isLogOnlyLine(context.getLine())) {
+                String tail = context.getLine().substring(context.getLine().lastIndexOf("]")+1);
+                enrichContext(context, tail);
+                getLogger().info(tail);
                 return false;
             } else {
                 return true;
@@ -256,4 +401,61 @@ private boolean lineContainsParseableEvent(String line) {
         return false;
     }
 
+    private void enrichContext(ParseContext context, String tail) {
+        Matcher regionSizeMatcher = tail != null ? PATTERN_HEAP_REGION_SIZE.matcher(tail.trim()) : null;
+        if (regionSizeMatcher != null && regionSizeMatcher.find()) {
+            try {
+                context.setRegionSize(Integer.parseInt(regionSizeMatcher.group(GROUP_HEAP_REGION_SIZE)));
+            } catch (NumberFormatException e) {
+                getLogger().warning(String.format("Failed to parse heap region size on line %d (line=%s)", in.getLineNumber(), context.getLine()));
+            }
+        }
+    }
+
+    private static class ParseContext {
+        /** G1 has a region size and logs the gc,heap information with # of regions */
+        private static final String REGION_SIZE_KEY = "regionSize";
+        private Map<String, AbstractGCEvent<?>> partialEventsMap;
+        private Map<String, Object> info;
+        private String line;
+        private AbstractGCEvent<?> currentEvent;
+
+        public ParseContext(String line, Map<String, AbstractGCEvent<?>> partialEventsMap, Map<String, Object> info) {
+            this.line = line;
+            this.partialEventsMap = partialEventsMap;
+            this.info = info;
+        }
+
+        public String getLine() {
+            return line;
+        }
+
+        public Map<String, AbstractGCEvent<?>> getPartialEventsMap() {
+            return partialEventsMap;
+        }
+
+        public AbstractGCEvent<?> getCurrentEvent() {
+            return currentEvent;
+        }
+
+        public void setCurrentEvent(AbstractGCEvent<?> currentEvent) {
+            this.currentEvent = currentEvent;
+        }
+
+        public int getRegionSize() {
+            Object regionSize = this.info.get(REGION_SIZE_KEY);
+            return regionSize != null ? (Integer)regionSize : 0;
+        }
+
+        public void setRegionSize(int regionSize) {
+            this.info.put(REGION_SIZE_KEY, regionSize);
+        }
+
+        @Override
+        public String toString() {
+            return line + (getRegionSize() > 0 ? "; regionsSize=" + getRegionSize() : "") + "; partialEventsMap.size()=" + partialEventsMap.size() + "currentEvent=" + getCurrentEvent();
+        }
+
+    }
+
 }
\ No newline at end of file
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/IBMJ9SAXHandler.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/IBMJ9SAXHandler.java
index 1398acba..91a4a30c 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/IBMJ9SAXHandler.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/IBMJ9SAXHandler.java
@@ -13,15 +13,14 @@
 import java.util.Locale;
 import java.util.logging.Logger;
 
-import org.xml.sax.Attributes;
-import org.xml.sax.SAXException;
-import org.xml.sax.helpers.DefaultHandler;
-
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.util.NumberParser;
+import org.xml.sax.Attributes;
+import org.xml.sax.SAXException;
+import org.xml.sax.helpers.DefaultHandler;
 
 /**
  * Simple (only for the -Xgcpolicy:optthruput output) IBMJ9 verbose GC reader.
@@ -263,7 +262,6 @@ public void endElement(String namespaceURI, String simpleName,
                     final GCEvent detailEvent = new GCEvent();
                     detailEvent.setTimestamp(currentAF.elapsedTime);
                     detailEvent.setType(AbstractGCEvent.Type.PS_YOUNG_GEN);
-                    detailEvent.setTenuredDetail(true);
                     detailEvent.setPreUsed(currentAF.getPreUsedSoaInKb());
                     detailEvent.setPostUsed(currentAF.getPostUsedSoaInKb());
                     detailEvent.setTotal(currentAF.getTotalSoaInKb());
@@ -278,7 +276,6 @@ public void endElement(String namespaceURI, String simpleName,
                     final GCEvent detailEvent = new GCEvent();
                     detailEvent.setTimestamp(currentAF.elapsedTime);
                     detailEvent.setType(AbstractGCEvent.Type.PS_OLD_GEN);
-                    detailEvent.setTenuredDetail(true);
                     detailEvent.setPreUsed(currentAF.getPreUsedLoaInKb());
                     detailEvent.setPostUsed(currentAF.getPostUsedLoaInKb());
                     detailEvent.setTotal(currentAF.getTotalLoaInKb());
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
index b62d377e..4ced53e8 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
@@ -19,21 +19,23 @@
  * @author <a href="mailto:hs@tagtraum.com">Hendrik Schreiber</a>
  * @author <a href="mailto:gcviewer@gmx.ch">Joerg Wuethrich</a>
  */
-public abstract class AbstractGCEvent<T extends AbstractGCEvent<T>> implements Serializable {
+public abstract class AbstractGCEvent<T extends AbstractGCEvent<T>> implements Serializable, Cloneable {
     /** Used before GC in KB */
     private int preUsed;
     /** Used after GC in KB */
     private int postUsed;
     /** Capacity in KB */
     private int total;
+    /** end of gc event (after pause) */
     private ZonedDateTime datestamp;
+    /** end of gc event (after pause) */
     private double timestamp;
     private ExtendedType extendedType = ExtendedType.UNDEFINED;
-    private boolean tenuredDetail;
     private String typeAsString;
-    private Generation generation;
+    protected Generation generation;
     protected List<T> details;
     private double pause;
+    private int number = -1;
 
     public Iterator<T> details() {
         if (details == null) return Collections.emptyIterator();
@@ -47,11 +49,8 @@ public void add(T detail) {
         }
         details.add(detail);
         typeAsString += "; " + detail.getExtendedType().getName();
-        if (detail.getExtendedType().getGeneration() == Generation.TENURED) {
-        	tenuredDetail = true;
-        }
 
-        // will be calculated upon call to "getGeneration()"
+        // reset cached value, which will be recalculated upon call to "getGeneration()"
         generation = null;
     }
 
@@ -60,14 +59,50 @@ public boolean hasDetails() {
                 && details.size() > 0;
     }
 
-    public boolean hasTenuredDetail() {
-        return tenuredDetail;
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+        AbstractGCEvent<T> clonedEvent = (AbstractGCEvent<T>)super.clone();
+        if (getDatestamp() != null) {
+            clonedEvent.setDateStamp(ZonedDateTime.from(this.getDatestamp()));
+        }
+        if (getExtendedType() != null) {
+            clonedEvent.setExtendedType(new ExtendedType(getExtendedType().getType(), getExtendedType().fullName));
+        }
+        if (details != null) {
+            List<T> detailClones = new ArrayList<>();
+            for (T t : details) {
+                detailClones.add((T)t.clone());
+            }
+            clonedEvent.details = detailClones;
+        }
+
+        // don't need to do anything with "generation", because that value is reset by the "add()" method
+
+        return clonedEvent;
+    }
+
+    public AbstractGCEvent<T> cloneAndMerge(AbstractGCEvent<T> otherEvent) {
+        try {
+            AbstractGCEvent<T> clonedEvent = (AbstractGCEvent<T>)otherEvent.clone();
+            clonedEvent.setExtendedType(new ExtendedType(getExtendedType().getType(), getExtendedType().fullName + "+" + clonedEvent.getExtendedType().fullName));
+            clonedEvent.setPreUsed(clonedEvent.getPreUsed() + getPreUsed());
+            clonedEvent.setPostUsed(clonedEvent.getPostUsed() + getPostUsed());
+            clonedEvent.setTotal(clonedEvent.getTotal() + getTotal());
+            clonedEvent.setPause(clonedEvent.getPause() + getPause());
+            return clonedEvent;
+        } catch (CloneNotSupportedException e) {
+            throw new RuntimeException("hmm, clone was not supported, that's unexpected...", e);
+        }
     }
 
     public void setDateStamp(ZonedDateTime datestamp) {
     	this.datestamp = datestamp;
     }
 
+    public void setNumber(int number) {
+        this.number = number;
+    }
+
     public void setTimestamp(double timestamp) {
         this.timestamp = timestamp;
     }
@@ -99,6 +134,10 @@ public ExtendedType getExtendedType() {
         return extendedType;
     }
 
+    public int getNumber() {
+        return number;
+    }
+
     public String getTypeAsString() {
     	return typeAsString;
     }
@@ -188,14 +227,7 @@ public int getTotal() {
 
     public abstract void toStringBuffer(StringBuffer sb);
 
-    public boolean isTenuredDetail() {
-        return tenuredDetail;
-    }
-
-    public void setTenuredDetail(boolean tenuredDetail) {
-        this.tenuredDetail = tenuredDetail;
-    }
-
+    @Override
 	public String toString() {
         StringBuffer sb = new StringBuffer(128);
         toStringBuffer(sb);
@@ -234,7 +266,7 @@ public boolean isConcurrentCollectionStart() {
                 || (getExtendedType().getName().equals(Type.UJL_CMS_CONCURRENT_MARK.getName()) && getPause() > 0.000001) // Universal jvm logging, CMS
                 || getExtendedType().getName().equals(Type.G1_CONCURRENT_MARK_START.getName()) // G1
                 || (getExtendedType().getName().equals(Type.UJL_G1_CONCURRENT_CYCLE.getName()) && getPause() < 0.00001) // Universal jvm logging, G1
-                || getExtendedType().getName().equals(Type.SHEN_CONCURRENT_CONC_MARK.getName()); // Universal jvm logging, Shenandoah
+                || getExtendedType().getName().equals(Type.UJL_SHEN_CONCURRENT_CONC_MARK.getName()); // Universal jvm logging, Shenandoah
     }
 
     public boolean isConcurrentCollectionEnd() {
@@ -243,13 +275,13 @@ public boolean isConcurrentCollectionEnd() {
                 || (getExtendedType().getName().equals(Type.UJL_CMS_CONCURRENT_RESET.getName()) && getPause() > 0.0000001) // Universal jvm logging, CMS
                 || getExtendedType().getName().equals(Type.G1_CONCURRENT_CLEANUP_END.getName()) // G1
                 || (getExtendedType().getName().equals(Type.UJL_G1_CONCURRENT_CYCLE.getName()) && getPause() > 0.0000001) // Universal jvm logging, G1
-                || getExtendedType().getName().equals(Type.SHEN_CONCURRENT_CONC_RESET_BITMAPS.getName()); // Universal jvm logging, Shenandoah
+                || getExtendedType().getName().equals(Type.UJL_SHEN_CONCURRENT_CONC_RESET_BITMAPS.getName()); // Universal jvm logging, Shenandoah
     }
 
     public boolean isInitialMark() {
         return getTypeAsString().indexOf("initial-mark") >= 0      // all others
-                || getTypeAsString().indexOf("Initial Mark") >= 0 // Unified jvm logging, CMS
-                || getTypeAsString().indexOf("Init Mark") >= 0; // Shenandoah
+                || getTypeAsString().indexOf("Initial Mark") >= 0 // Unified jvm logging, CMS + G1
+                || getTypeAsString().indexOf("Init Mark") >= 0; // Unified jvm logging, Shenandoah
     }
 
     public boolean isRemark() {
@@ -257,7 +289,7 @@ public boolean isRemark() {
                 || getTypeAsString().indexOf(Type.ASCMS_REMARK.getName()) >= 0
                 || getTypeAsString().indexOf(Type.G1_REMARK.getName()) >= 0
                 || getTypeAsString().indexOf(Type.UJL_PAUSE_REMARK.getName()) >= 0
-                || getTypeAsString().indexOf(Type.SHEN_STW_FINAL_MARK.getName()) >= 0;
+                || getTypeAsString().indexOf(Type.UJL_SHEN_FINAL_MARK.getName()) >= 0;
     }
 
     public boolean hasPause() {
@@ -282,7 +314,6 @@ public boolean equals(Object o) {
             return false;
         AbstractGCEvent<?> that = (AbstractGCEvent<?>) o;
         return Double.compare(that.timestamp, timestamp) == 0 &&
-                tenuredDetail == that.tenuredDetail &&
                 Double.compare(that.pause, pause) == 0 &&
                 Objects.equals(datestamp, that.datestamp) &&
                 Objects.equals(extendedType, that.extendedType) &&
@@ -293,7 +324,7 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-        return Objects.hash(datestamp, timestamp, extendedType, tenuredDetail, typeAsString, generation, details);
+        return Objects.hash(datestamp, timestamp, extendedType, typeAsString, generation, details);
     }
 
     /**
@@ -333,6 +364,7 @@ public static ExtendedType lookup(Type type, String fullName) {
                 WRAPPER_MAP.put(fullName, extType);
             }
 
+
             return extType;
         }
 
@@ -360,6 +392,24 @@ public Concurrency getConcurrency() {
             return type.getConcurrency();
         }
 
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            ExtendedType that = (ExtendedType) o;
+            return Objects.equals(fullName, that.fullName);
+        }
+
+        @Override
+        public int hashCode() {
+
+            return Objects.hash(fullName);
+        }
+
         @Override
         public String toString() {
             return fullName;
@@ -564,8 +614,8 @@ public String toString() {
         public static final Type UJL_PAUSE_FULL_SYSTEM = new Type("Pause Full (System.gc())", Generation.ALL, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
 
         // unified jvm logging cms / g1 event types
-        public static final Type UJL_PAUSE_INITIAL_MARK = new Type("Pause Initial Mark", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
-        public static final Type UJL_PAUSE_REMARK = new Type("Pause Remark", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
+        public static final Type UJL_PAUSE_INITIAL_MARK = new Type("Pause Initial Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
+        public static final Type UJL_PAUSE_REMARK = new Type("Pause Remark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
 
         // unified jvm logging cms event types
         public static final Type UJL_CMS_CONCURRENT_MARK = new Type("Concurrent Mark", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
@@ -573,24 +623,28 @@ public String toString() {
         public static final Type UJL_CMS_CONCURRENT_ABORTABLE_PRECLEAN = new Type("Concurrent Abortable Preclean", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
         public static final Type UJL_CMS_CONCURRENT_SWEEP = new Type("Concurrent Sweep", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
         public static final Type UJL_CMS_CONCURRENT_RESET = new Type("Concurrent Reset", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
+        public static final Type UJL_CMS_CONCURRENT_OLD = new Type("Old", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY);
 
         // unified jvm logging g1 event types
         public static final Type UJL_G1_PAUSE_MIXED = new Type("Pause Mixed", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
         public static final Type UJL_G1_TO_SPACE_EXHAUSTED = new Type("To-space exhausted", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC);
         public static final Type UJL_G1_CONCURRENT_CYCLE = new Type("Concurrent Cycle", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_PAUSE);
         public static final Type UJL_G1_PAUSE_CLEANUP = new Type("Pause Cleanup", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE, CollectionType.CONCURRENCY_HELPER);
+        public static final Type UJL_G1_EDEN = new Type("Eden regions", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC_REGION);
+        public static final Type UJL_G1_SURVIVOR = new Type("Survivor regions", Generation.YOUNG, Concurrency.SERIAL, GcPattern.GC_REGION);
+        public static final Type UJL_G1_OLD = new Type("Old regions", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_REGION);
+        public static final Type UJL_G1_HUMongous = new Type("Humongous regions", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_REGION);
 
         // unified jvm logging shenandoah event types
-        // TODO rename events to start with UJL_...
-        public static final Type SHEN_STW_INIT_MARK = new Type("Pause Init Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
-        public static final Type SHEN_STW_FINAL_MARK = new Type("Pause Final Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_STW_INIT_UPDATE_REFS = new Type("Pause Init Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
-        public static final Type SHEN_STW_FINAL_UPDATE_REFS = new Type("Pause Final Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_CONCURRENT_CONC_MARK = new Type("Concurrent marking", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_CONCURRENT_CONC_EVAC = new Type("Concurrent evacuation", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_CONCURRENT_CONC_RESET_BITMAPS = new Type("Concurrent reset bitmaps", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_CONCURRENT_CONC_UPDATE_REFS = new Type("Concurrent update references", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
-        public static final Type SHEN_CONCURRENT_PRECLEANING = new Type("Concurrent precleaning", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_INIT_MARK = new Type("Pause Init Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
+        public static final Type UJL_SHEN_FINAL_MARK = new Type("Pause Final Mark", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_INIT_UPDATE_REFS = new Type("Pause Init Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_PAUSE);
+        public static final Type UJL_SHEN_FINAL_UPDATE_REFS = new Type("Pause Final Update Refs", Generation.TENURED, Concurrency.SERIAL, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_CONCURRENT_CONC_MARK = new Type("Concurrent marking", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_CONCURRENT_CONC_EVAC = new Type("Concurrent evacuation", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_CONCURRENT_CONC_RESET_BITMAPS = new Type("Concurrent reset bitmaps", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_CONCURRENT_CONC_UPDATE_REFS = new Type("Concurrent update references", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
+        public static final Type UJL_SHEN_CONCURRENT_PRECLEANING = new Type("Concurrent precleaning", Generation.TENURED, Concurrency.CONCURRENT, GcPattern.GC_MEMORY_PAUSE);
 
         // IBM Types
         // TODO: are scavenge always young only??
@@ -609,21 +663,34 @@ public String toString() {
 
     }
 
-    public static enum GcPattern {
-        // <timestamp>: [<GC type>]
+    /**
+     * Patterns of additional information for gc events.
+     * <ul>
+     *     <li><code>GC</code>: just the name of the event type</li>
+     *     <li><code>PAUSE</code>: length of a pause</li>
+     *     <li><code>DURATION</code>: cycle time of a (usually concurrent) event</li>
+     *     <li><code>MEMORY</code>: information about heap changes</li></li>
+     *     <li><code>REGION</code>: information about number of regions used (only G1 up to now)</li>
+     * </ul>
+     */
+    public enum GcPattern {
+        /** "GC type" (just the name, no additional information) */
         GC,
-        // <timestamp>: [<GC type>, <pause>]
+        /** "GC type": "pause" */
         GC_PAUSE,
-        // <timestamp>: [<GC type>, <pause>/<duration>]
+        /** "GC type": "pause"/"duration" */
         GC_PAUSE_DURATION,
-        // [<GC type>, <mem current>(<mem total>)]
+        /** "GC type": "memory current"("memory total") */
         GC_MEMORY,
-        // <timestamp>: [<GC type> <mem before>-><mem after>(<mem total>), <pause>]
-    	GC_MEMORY_PAUSE}
+        /** "GC type": "memory before"-&gt;"memory after"("memory total"), "pause" */
+    	GC_MEMORY_PAUSE,
+        /** "GC type": "# regions before"-&gt;"# regions after"[("#total regions")] ("total regions" is optional; needs a region size to calculate memory usage)*/
+        GC_REGION,
+    }
 
-    public static enum Concurrency { CONCURRENT, SERIAL };
+    public enum Concurrency { CONCURRENT, SERIAL };
 
-    public static enum Generation { YOUNG,
+    public enum Generation { YOUNG,
         TENURED,
         /** also used for "metaspace" that is introduced with java 8 */
         PERM,
@@ -631,7 +698,7 @@ public static enum Generation { YOUNG,
         /** special value for vm operations that are not collections */
         OTHER };
 
-    public static enum CollectionType {
+    public enum CollectionType {
         /** plain GC pause collection garbage */
         COLLECTION,
         /**
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/ConcurrentGCEvent.java b/src/main/java/com/tagtraum/perf/gcviewer/model/ConcurrentGCEvent.java
index e2e4642c..c0b04f0b 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/model/ConcurrentGCEvent.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/ConcurrentGCEvent.java
@@ -24,6 +24,11 @@ public double getDuration() {
         return duration;
     }
 
+    @Override
+    public ConcurrentGCEvent cloneAndMerge(AbstractGCEvent<ConcurrentGCEvent> otherEvent) {
+        return (ConcurrentGCEvent)super.cloneAndMerge(otherEvent);
+    }
+
     /**
      * Set duration.
      * @see #getDuration()
@@ -40,6 +45,9 @@ public boolean hasDuration() {
 	public void toStringBuffer(StringBuffer sb) {
         sb.append(getTimestamp());
         sb.append(": [");
+        if (getNumber() >= 0) {
+            sb.append(" GC(").append(getNumber()).append(") ");
+        }
         sb.append(getExtendedType().getName());
         if (hasMemoryInformation()) {
             sb.append(' ');
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/GCEvent.java b/src/main/java/com/tagtraum/perf/gcviewer/model/GCEvent.java
index b1d3340c..25a47c81 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/model/GCEvent.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/GCEvent.java
@@ -1,7 +1,10 @@
 package com.tagtraum.perf.gcviewer.model;
 
+import java.util.Iterator;
 import java.util.Objects;
 
+import com.tagtraum.perf.gcviewer.util.DateHelper;
+
 /**
  * The GCEvent is the type of event that contains memory (preused, postused, total) and 
  * pause information.
@@ -34,15 +37,19 @@ public GCEvent(double timestamp, int preUsed, int postUsed, int total, double pa
     public void add(GCEvent event) {
         super.add(event);
 
+        setReferencedEvent(event);
+    }
+
+    private void setReferencedEvent(GCEvent event) {
         switch (event.getExtendedType().getGeneration()) {
             case YOUNG:
-                young = event;
+                young = young == null ? event : young.cloneAndMerge(event);
                 break;
             case TENURED:
-                tenured = event;
+                tenured = tenured == null ? event : tenured.cloneAndMerge(event);
                 break;
             case PERM:
-                perm = event;
+                perm = perm == null ? event : perm.cloneAndMerge(event);
                 break;
             // ALL and OTHER are never read
             case ALL:
@@ -51,7 +58,33 @@ public void add(GCEvent event) {
                 break;
         }
     }
-    
+
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+        GCEvent[] events = {young, tenured, perm};
+        young = null;
+        tenured = null;
+        perm = null;
+
+        GCEvent clonedEvent = (GCEvent)super.clone();
+
+        Iterator<GCEvent> eventIterator = clonedEvent.details();
+        while (eventIterator.hasNext()) {
+            clonedEvent.setReferencedEvent(eventIterator.next());
+        }
+
+        young = events[0];
+        tenured = events[1];
+        perm = events[2];
+
+        return clonedEvent;
+    }
+
+    @Override
+    public GCEvent cloneAndMerge(AbstractGCEvent<GCEvent> otherEvent) {
+        return (GCEvent)super.cloneAndMerge(otherEvent);
+    }
+
     /**
      * Returns information on young generation. If it was not present in the gc log, but 
      * tenured was, it is inferred from there (with -XX:+PrintGCDetails). Otherwise it is 
@@ -107,9 +140,14 @@ public GCEvent getPerm() {
     }
 
     public void toStringBuffer(StringBuffer sb) {
-        sb.append(getTimestamp());
-        sb.append(": [");
-        sb.append(getExtendedType() != null ? getExtendedType().getName() : ExtendedType.UNDEFINED);
+        if (getDatestamp() != null) {
+            sb.append("[").append(DateHelper.formatDate(getDatestamp())).append("]");
+        }
+        sb.append("[").append(getTimestamp()).append("]");
+        if (getNumber() >= 0) {
+            sb.append(" GC(").append(getNumber()).append(")");
+        }
+        sb.append(" [").append(getExtendedType() != null ? getExtendedType().getName() : ExtendedType.UNDEFINED);
         if (details != null) {
             sb.append(' ');
             for (AbstractGCEvent event : details) {
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/GCEventUJL.java b/src/main/java/com/tagtraum/perf/gcviewer/model/GCEventUJL.java
new file mode 100644
index 00000000..1a37c157
--- /dev/null
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/GCEventUJL.java
@@ -0,0 +1,27 @@
+package com.tagtraum.perf.gcviewer.model;
+
+/**
+ * @author <a href="mailto:gcviewer@gmx.ch">Joerg Wuethrich</a>
+ * <p>created on: 03.01.2018</p>
+ */
+public class GCEventUJL extends GCEvent {
+
+    @Override
+    public boolean isFull() {
+        // assumption AbstractGCEvent does not hold here; only the event type itself can tell
+        return getExtendedType().getGeneration().equals(Generation.ALL);
+    }
+
+    @Override
+    public Generation getGeneration() {
+        // assumption in AbstractGCEvent concerning "has information about several generations"
+        // -> "has collected objects from several generations" is not correct for unified jvm logging events
+        // they usually seem to hold information about several generations, as soon as heap details are logged
+        if (generation == null) {
+            generation = getExtendedType() != null ? getExtendedType().getGeneration() : null;
+        }
+
+        return generation == null ? Generation.YOUNG : generation;
+    }
+
+}
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/util/DateHelper.java b/src/main/java/com/tagtraum/perf/gcviewer/util/DateHelper.java
new file mode 100644
index 00000000..2073c5b6
--- /dev/null
+++ b/src/main/java/com/tagtraum/perf/gcviewer/util/DateHelper.java
@@ -0,0 +1,21 @@
+package com.tagtraum.perf.gcviewer.util;
+
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+
+/**
+ * @author <a href="mailto:gcviewer@gmx.ch">Joerg Wuethrich</a>
+ * <p>created on: 02.01.2018</p>
+ */
+public class DateHelper {
+    public static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+
+    public static ZonedDateTime parseDate(String dateStampAsString) {
+        return ZonedDateTime.parse(dateStampAsString, DateHelper.DATE_TIME_FORMATTER);
+    }
+
+    public static String formatDate(ZonedDateTime dateTime) {
+        return DATE_TIME_FORMATTER.format(dateTime);
+    }
+
+}
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
index 7d842bcf..c916f4c6 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
@@ -1,6 +1,8 @@
 package com.tagtraum.perf.gcviewer;
 
+import static org.hamcrest.Matchers.closeTo;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertThat;
 
 import java.io.File;
@@ -12,6 +14,9 @@
 import com.tagtraum.perf.gcviewer.imp.DataReader;
 import com.tagtraum.perf.gcviewer.imp.DataReaderFactory;
 import com.tagtraum.perf.gcviewer.imp.TestLogHandler;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Generation;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
@@ -140,4 +145,34 @@ public static GCModel getGCModelFromLogFile(String fileName, FOLDER folderName,
         }
     }
 
+    /**
+     * Tests a given <code>event</code> for several of its attribute values.
+     * @param event event under test
+     * @param testName expressive name for the current test
+     * @param expectedType expected type
+     * @param expectedPause expected pause duration
+     * @param expectedHeapBefore expected heap size before
+     * @param expectedHeapAfter expected heap size after
+     * @param expectedHeapTotal expected total heap size
+     * @param expectedValueForIsFull expected value for "is full gc event"
+     */
+    public static void testMemoryPauseEvent(AbstractGCEvent<?> event,
+                                      String testName,
+                                      Type expectedType,
+                                      double expectedPause,
+                                      int expectedHeapBefore,
+                                      int expectedHeapAfter,
+                                      int expectedHeapTotal,
+                                      Generation expectedGeneration,
+                                      boolean expectedValueForIsFull) {
+
+        assertThat(testName + " type", event.getTypeAsString(), startsWith(expectedType.getName()));
+        assertThat(testName + " pause", event.getPause(), closeTo(expectedPause, 0.00001));
+        assertThat(testName + " heap before", event.getPreUsed(), is(expectedHeapBefore));
+        assertThat(testName + " heap after", event.getPostUsed(), is(expectedHeapAfter));
+        assertThat(testName + " total heap", event.getTotal(), is(expectedHeapTotal));
+        assertThat(testName + " generation", event.getGeneration(), is(expectedGeneration));
+        assertThat(testName + " isFull", event.isFull(), is(expectedValueForIsFull));
+    }
+
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
index 09c1f5a2..1a2da0bc 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0.java
@@ -19,11 +19,12 @@
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import org.junit.Test;
 
 public class TestDataReaderSun1_6_0 {
 
-    private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
+    private final DateTimeFormatter dateTimeFormatter = DateHelper.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
         return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
index 2334b46e..3dfafab6 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_6_0G1.java
@@ -19,11 +19,12 @@
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import org.junit.Test;
 
 public class TestDataReaderSun1_6_0G1 {
     
-    private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
+    private final DateTimeFormatter dateTimeFormatter = DateHelper.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
         return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
index f9cca111..df8f96aa 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderSun1_7_0.java
@@ -20,6 +20,7 @@
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import com.tagtraum.perf.gcviewer.model.GCResource;
 import com.tagtraum.perf.gcviewer.model.GcResourceFile;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import org.junit.Test;
 
 /**
@@ -30,7 +31,7 @@
  */
 public class TestDataReaderSun1_7_0 {
 
-    private final DateTimeFormatter dateTimeFormatter = AbstractDataReaderSun.DATE_TIME_FORMATTER;
+    private final DateTimeFormatter dateTimeFormatter = DateHelper.DATE_TIME_FORMATTER;
 
     private InputStream getInputStream(String fileName) throws IOException {
         return UnittestHelper.getResourceAsStream(FOLDER.OPENJDK, fileName);
@@ -408,8 +409,8 @@ public void cmsPrintFlsStatistics1() throws Exception {
 
         assertThat("GC count", model.size(), is(3));
         assertThat("event 1 pause", model.get(0).getPause(), closeTo(0.0030039, 0.00000001));
-        assertThat("event 2", model.get(1).isConcurrent(), is(true));
-        assertThat("event 3", model.get(2).isFull(), is(true));
+        assertThat("event 2 is concurrent", model.get(1).isConcurrent(), is(true));
+        assertThat("event 3 is full", model.get(2).isFull(), is(true));
         assertThat("event 3 pause", model.get(2).getPause(), closeTo(0.0339164, 0.00000001));
         assertThat("number of parse problems", handler.getCount(), is(0));
 
@@ -427,11 +428,11 @@ public void cmsPrintFlsStatistics2() throws Exception {
 
         assertThat("GC count", model.size(), is(5));
         assertThat("event 1 pause", model.get(0).getPause(), closeTo(0.0054252, 0.00000001));
-        assertThat("event 2", model.get(1).isConcurrent(), is(true));
-        assertThat("event 3", model.get(2).isFull(), is(true));
+        assertThat("event 2 is concurrent", model.get(1).isConcurrent(), is(true));
+        assertThat("event 3 is full", model.get(2).isFull(), is(true));
         assertThat("event 3 pause", model.get(2).getPause(), closeTo(0.0356364, 0.00000001));
-        assertThat("event 4", model.get(3).isConcurrent(), is(true));
-        assertThat("event 5", model.get(4).isFull(), is(true));
+        assertThat("event 4 is concurrent", model.get(3).isConcurrent(), is(true));
+        assertThat("event 5 is full", model.get(4).isFull(), is(true));
         assertThat("event 5 pause", model.get(4).getPause(), closeTo(0.0264843, 0.00000001));
         assertThat("number of parse problems", handler.getCount(), is(0));
 
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
index 903b01ba..95fa2266 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLCMS.java
@@ -1,8 +1,6 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import static org.hamcrest.Matchers.closeTo;
 import static org.hamcrest.Matchers.is;
-import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
@@ -10,6 +8,7 @@
 import com.tagtraum.perf.gcviewer.UnittestHelper;
 import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Generation;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import org.junit.Test;
@@ -26,38 +25,48 @@ private GCModel getGCModelFromLogFile(String fileName) throws IOException {
     public void parseGcDefaults() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-cms-gc-defaults.txt");
         assertThat("size", model.size(), is(16));
-        assertThat("amount gc events", model.getGcEventPauses().size(), is(3));
-        assertThat("amount full gc events", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of gc event types", model.getGcEventPauses().size(), is(3));
+        assertThat("amount of gc events", model.getGCPause().getN(), is(5));
+        assertThat("amount of full gc event types", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of full gc events", model.getFullGCPause().getN(), is(1));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(5));
 
-        testMemoryPauseEvent(model.get(0),
+        UnittestHelper.testMemoryPauseEvent(model.get(0),
                 "young",
                 Type.UJL_PAUSE_YOUNG,
                 0.008822,
-                1024 * 41, 1024 * 38,1024 * 150);
+                1024 * 41, 1024 * 38,1024 * 150,
+                Generation.YOUNG,
+                false);
 
         AbstractGCEvent<?> event2 = model.get(1);
-        testMemoryPauseEvent(event2,
+        UnittestHelper.testMemoryPauseEvent(event2,
                 "initialMarkEvent",
                 Type.UJL_PAUSE_INITIAL_MARK,
                 0.000136,
-                1024 * 61, 1024 * 61,1024 * 150);
+                1024 * 61, 1024 * 61,1024 * 150,
+                Generation.TENURED,
+                false);
         assertThat("isInitialMark", event2.isInitialMark(), is(true));
 
         AbstractGCEvent<?> event3 = model.get(10);
-        testMemoryPauseEvent(event3,
+        UnittestHelper.testMemoryPauseEvent(event3,
                 "RemarkEvent",
                 Type.UJL_PAUSE_REMARK,
                 0.000859,
-                1024 * 110, 1024 * 110,1024 * 150);
+                1024 * 110, 1024 * 110,1024 * 150,
+                Generation.TENURED,
+                false);
         assertThat("isRemark", event3.isRemark(), is(true));
 
         AbstractGCEvent<?> event4 = model.get(15);
-        testMemoryPauseEvent(event4,
+        UnittestHelper.testMemoryPauseEvent(event4,
                 "full",
                 Type.UJL_PAUSE_FULL,
                 0.009775,
-                1024 * 125, 1024 * 31, 1024 * 150);
+                1024 * 125, 1024 * 31, 1024 * 150,
+                Generation.ALL,
+                true);
 
         AbstractGCEvent<?> concurrentMarkBeginEvent = model.get(2);
         assertThat("event is not start of concurrent collection", concurrentMarkBeginEvent.isConcurrentCollectionStart(), is(false));
@@ -82,38 +91,45 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(4));
 
         AbstractGCEvent<?> event1 = model.get(0);
-        testMemoryPauseEvent(event1,
+        UnittestHelper.testMemoryPauseEvent(event1,
                 "young",
                 Type.UJL_PAUSE_YOUNG,
                 0.009618,
-                1024 * 41, 1024 * 38, 1024 * 150);
+                1024 * 41, 1024 * 38, 1024 * 150,
+                Generation.YOUNG,
+                false);
 
         // GC(3) Pause Initial Mark
         AbstractGCEvent<?> event2 = model.get(3);
-        testMemoryPauseEvent(event2,
+        UnittestHelper.testMemoryPauseEvent(event2,
                 "initial mark",
                 Type.UJL_PAUSE_INITIAL_MARK,
                 0.000165,
-                91 * 1024, 91 * 1024, 150 * 1024);
+                91 * 1024, 91 * 1024, 150 * 1024,
+                Generation.TENURED,
+                false);
         assertThat("isInitialMark", event2.isInitialMark(), is(true));
 
         // GC(3) Pause Remark
         AbstractGCEvent<?> remarkEvent = model.get(10);
-        testMemoryPauseEvent(remarkEvent,
+        UnittestHelper.testMemoryPauseEvent(remarkEvent,
                 "remark",
                 Type.UJL_PAUSE_REMARK,
                 0.000908,
-                130 * 1024, 130 * 1024, 150 * 1024);
+                130 * 1024, 130 * 1024, 150 * 1024,
+                Generation.TENURED,
+                false);
         assertThat("isRemark", remarkEvent.isRemark(), is(true));
 
         // GC(5) Pause Full
         AbstractGCEvent<?> fullGcEvent = model.get(13);
-        testMemoryPauseEvent(fullGcEvent,
+        UnittestHelper.testMemoryPauseEvent(fullGcEvent,
                 "full gc ",
                 Type.UJL_PAUSE_FULL,
                 0.009509,
-                119 * 1024, 33 * 1024, 150 * 1024);
-        assertThat("isFull", fullGcEvent.isFull(), is(true));
+                119 * 1024, 33 * 1024, 150 * 1024,
+                Generation.ALL,
+                true);
 
         AbstractGCEvent<?> concurrentMarkBeginEvent = model.get(4);
         assertThat("event is not start of concurrent collection", concurrentMarkBeginEvent.isConcurrentCollectionStart(), is(false));
@@ -122,19 +138,4 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         assertThat("event is start of concurrent collection", concurrentMarkWithPauseEvent.isConcurrentCollectionStart(), is(true));
     }
 
-    private void testMemoryPauseEvent(AbstractGCEvent<?> event,
-                                      String eventName,
-                                      Type type,
-                                      double pause,
-                                      int heapBefore,
-                                      int heapAfter,
-                                      int heapTotal) {
-
-        assertThat(eventName + " type", event.getTypeAsString(), startsWith(type.getName()));
-        assertThat(eventName + " pause", event.getPause(), closeTo(pause, 0.00001));
-        assertThat(eventName + " heap before", event.getPreUsed(), is(heapBefore));
-        assertThat(eventName + " heap after", event.getPostUsed(), is(heapAfter));
-        assertThat(eventName + " total heap", event.getTotal(), is(heapTotal));
-    }
-
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
index 19f53ed0..deee20b6 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLG1.java
@@ -1,16 +1,18 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import static org.hamcrest.Matchers.closeTo;
+import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
-import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
+import java.util.Iterator;
 
 import com.tagtraum.perf.gcviewer.UnittestHelper;
 import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Generation;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import com.tagtraum.perf.gcviewer.model.GCEventUJL;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import org.junit.Test;
 
@@ -26,56 +28,71 @@ private GCModel getGCModelFromLogFile(String fileName) throws IOException {
     public void parseGcDefaults() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-g1-gc-defaults.txt");
         assertThat("size", model.size(), is(15));
-        assertThat("amount gc events", model.getGcEventPauses().size(), is(6));
-        assertThat("amount full gc events", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of gc event types", model.getGcEventPauses().size(), is(6));
+        assertThat("amount of gc events", model.getGCPause().getN(), is(12));
+        assertThat("amount of full gc event types", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of full gc events", model.getFullGCPause().getN(), is(1));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(1));
 
-        testMemoryPauseEvent(model.get(0),
+        UnittestHelper.testMemoryPauseEvent(model.get(0),
                 "young",
                 Type.UJL_PAUSE_YOUNG,
                 0.006529,
-                1024 * 14, 1024 * 12,1024 * 128);
+                1024 * 14, 1024 * 12, 1024 * 128,
+                Generation.YOUNG,
+                false);
 
         AbstractGCEvent<?> mixedEvent = model.get(14);
-        testMemoryPauseEvent(mixedEvent,
+        UnittestHelper.testMemoryPauseEvent(mixedEvent,
                 "mixed",
                 Type.UJL_G1_PAUSE_MIXED,
                 0.002790,
-                1024 * 29, 1024 * 28, 1024 * 123);
+                1024 * 29, 1024 * 28, 1024 * 123,
+                Generation.TENURED,
+                false);
 
         AbstractGCEvent<?> initialMarkEvent = model.get(1);
-        testMemoryPauseEvent(initialMarkEvent,
+        UnittestHelper.testMemoryPauseEvent(initialMarkEvent,
                 "initialMarkEvent",
                 Type.UJL_PAUSE_INITIAL_MARK,
                 0.006187,
-                1024 * 80, 1024 * 80,1024 * 128);
+                1024 * 80, 1024 * 80, 1024 * 128,
+                Generation.TENURED,
+                false);
         assertThat("isInitialMark", initialMarkEvent.isInitialMark(), is(true));
 
         AbstractGCEvent<?> remarkEvent = model.get(6);
-        testMemoryPauseEvent(remarkEvent,
+        UnittestHelper.testMemoryPauseEvent(remarkEvent,
                 "RemarkEvent",
                 Type.UJL_PAUSE_REMARK,
                 0.000837,
-                1024 * 121, 1024 * 121,1024 * 128);
+                1024 * 121, 1024 * 121, 1024 * 128,
+                Generation.TENURED,
+                false);
         assertThat("isRemark", remarkEvent.isRemark(), is(true));
 
         AbstractGCEvent<?> fullGcEvent = model.get(11);
-        testMemoryPauseEvent(fullGcEvent,
+        UnittestHelper.testMemoryPauseEvent(fullGcEvent,
                 "full",
                 Type.UJL_PAUSE_FULL,
                 0.014918,
-                1024 * 128, 1024 * 8, 1024 * 28);
-        assertThat("isFull", fullGcEvent.isFull(), is(true));
+                1024 * 128, 1024 * 8, 1024 * 28,
+                Generation.ALL,
+                true);
 
         AbstractGCEvent<?> cleanupEvent = model.get(12);
-        testMemoryPauseEvent(cleanupEvent,
+        UnittestHelper.testMemoryPauseEvent(cleanupEvent,
                 "cleanup",
                 Type.UJL_G1_PAUSE_CLEANUP,
                 0.000001,
-                1024 * 9, 1024 * 9, 1024 * 28);
+                1024 * 9, 1024 * 9, 1024 * 28,
+                Generation.TENURED,
+                false);
 
         AbstractGCEvent<?> concurrentCycleBegin = model.get(2);
-        assertThat("event is start of concurrent collection", concurrentCycleBegin.isConcurrentCollectionStart(), is(true));
+        assertThat("event is start of concurrent collection",
+                concurrentCycleBegin.isConcurrentCollectionStart(),
+                is(true));
 
         AbstractGCEvent<?> concurrentCycleEnd = model.get(13);
         assertThat("event is end of concurrent collection", concurrentCycleEnd.isConcurrentCollectionEnd(), is(true));
@@ -87,61 +104,94 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-g1-gc-all,safepoint,os+cpu.txt");
         assertThat("size", model.size(), is(15));
         assertThat("amount of STW GC pause types", model.getGcEventPauses().size(), is(4));
+        assertThat("amount of STW GC pauses", model.getGCPause().getN(), is(13));
         assertThat("amount of STW Full GC pause types", model.getFullGcEventPauses().size(), is(0));
+        assertThat("amount of STW Full GC pauses", model.getFullGCPause().getN(), is(0));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(1));
 
         AbstractGCEvent<?> event1 = model.get(0);
-        testMemoryPauseEvent(event1,
+        UnittestHelper.testMemoryPauseEvent(event1,
                 "young",
                 Type.UJL_PAUSE_YOUNG,
                 0.007033,
-                1024 * 14, 1024 * 12, 1024 * 128);
+                1024 * 14, 1024 * 12, 1024 * 128,
+                Generation.YOUNG,
+                false);
+        assertThat("young heap before", event1.details().next().getPreUsed(), is(1024 * 14));
 
         // GC(3) Pause Initial Mark
         AbstractGCEvent<?> event2 = model.get(5);
-        testMemoryPauseEvent(event2,
+        UnittestHelper.testMemoryPauseEvent(event2,
                 "initial mark",
                 Type.UJL_PAUSE_INITIAL_MARK,
                 0.005011,
-                1024 * 80, 1024 * 80, 1024 * 128);
+                1024 * 80, 1024 * 80, 1024 * 128,
+                Generation.TENURED,
+                false);
         assertThat("isInitialMark", event2.isInitialMark(), is(true));
 
         // GC(3) Pause Remark
         AbstractGCEvent<?> remarkEvent = model.get(10);
-        testMemoryPauseEvent(remarkEvent,
+        UnittestHelper.testMemoryPauseEvent(remarkEvent,
                 "remark",
                 Type.UJL_PAUSE_REMARK,
                 0.000939,
-                1024 * 113, 1024 * 113, 1024 * 128);
+                1024 * 113, 1024 * 113, 1024 * 128,
+                Generation.TENURED,
+                false);
         assertThat("isRemark", remarkEvent.isRemark(), is(true));
 
         AbstractGCEvent<?> cleanupEvent = model.get(13);
-        testMemoryPauseEvent(cleanupEvent,
+        UnittestHelper.testMemoryPauseEvent(cleanupEvent,
                 "cleanup",
                 Type.UJL_G1_PAUSE_CLEANUP,
                 0.000367,
-                1024 * 114, 1024 * 70, 1024 * 128);
+                1024 * 114, 1024 * 70, 1024 * 128,
+                Generation.TENURED,
+                false);
 
         AbstractGCEvent<?> concurrentCycleBeginEvent = model.get(6);
-        assertThat("event is start of concurrent collection", concurrentCycleBeginEvent.isConcurrentCollectionStart(), is(true));
+        assertThat("event is start of concurrent collection",
+                concurrentCycleBeginEvent.isConcurrentCollectionStart(),
+                is(true));
 
         AbstractGCEvent<?> concurrentCycleEndEvent = model.get(14);
-        assertThat("event is end of concurrent collection", concurrentCycleEndEvent.isConcurrentCollectionEnd(), is(true));
+        assertThat("event is end of concurrent collection",
+                concurrentCycleEndEvent.isConcurrentCollectionEnd(),
+                is(true));
     }
 
-    private void testMemoryPauseEvent(AbstractGCEvent<?> event,
-                                      String eventName,
-                                      Type type,
-                                      double pause,
-                                      int heapBefore,
-                                      int heapAfter,
-                                      int heapTotal) {
-
-        assertThat(eventName + " type", event.getTypeAsString(), startsWith(type.getName()));
-        assertThat(eventName + " pause", event.getPause(), closeTo(pause, 0.00001));
-        assertThat(eventName + " heap before", event.getPreUsed(), is(heapBefore));
-        assertThat(eventName + " heap after", event.getPostUsed(), is(heapAfter));
-        assertThat(eventName + " total heap", event.getTotal(), is(heapTotal));
+    @Test
+    public void parseGcAllSafepointOsCpuWithToSpaceExhausted() throws Exception {
+        GCModel model = getGCModelFromLogFile("sample-ujl-g1-gc-all,safepoint,os+cpu-to-space-exhausted.txt");
+        assertThat("size", model.size(), is(1));
+        AbstractGCEvent<?> youngEvent = model.get(0);
+        UnittestHelper.testMemoryPauseEvent(youngEvent,
+                "young",
+                Type.UJL_PAUSE_YOUNG,
+                0.002717,
+                1024 * 116, 1024 * 119, 1024 * 128,
+                Generation.YOUNG,
+                false);
+        assertThat("typeAsString", youngEvent.getTypeAsString(), equalTo("Pause Young (G1 Evacuation Pause); To-space exhausted; Eden regions:; Survivor regions:; Old regions:; Humongous regions:; Metaspace:"));
+        Iterator<AbstractGCEvent<?>> iterator = (Iterator<AbstractGCEvent<?>>) youngEvent.details();
+        // skip "To-space exhausted"
+        iterator.next();
+        testHeapSizing(iterator.next(), "eden", 0, 0, 0);
+        testHeapSizing(iterator.next(), "survivor", 0, 0, 0);
+        testHeapSizing(iterator.next(), "old", 0, 0, 0);
+        testHeapSizing(iterator.next(), "humongous", 0, 0, 0);
+        testHeapSizing(iterator.next(), "metaspace", 3648, 3648, 1056768);
+
+        GCEventUJL gcEventUJL = (GCEventUJL)youngEvent;
+        testHeapSizing(gcEventUJL.getYoung(), "young", 0, 0, 0);
+        testHeapSizing(gcEventUJL.getTenured(), "tenured", 0, 0, 0);
+        testHeapSizing(gcEventUJL.getPerm(), "metaspace", 3648, 3648, 1056768);
     }
 
+    private void testHeapSizing(AbstractGCEvent<?> event, String testName, int expectedBefore, int expectedAfter, int expectedTotal) {
+        assertThat(testName + " before", event.getPreUsed(), is(expectedBefore));
+        assertThat(testName + " after", event.getPostUsed(), is(expectedAfter));
+        assertThat(testName + " total", event.getTotal(), is(expectedTotal));
+    }
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
index 89c179dc..6068fefc 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLParallel.java
@@ -1,8 +1,6 @@
 package com.tagtraum.perf.gcviewer.imp;
 
-import static org.hamcrest.Matchers.closeTo;
 import static org.hamcrest.Matchers.is;
-import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
@@ -10,6 +8,7 @@
 import com.tagtraum.perf.gcviewer.UnittestHelper;
 import com.tagtraum.perf.gcviewer.UnittestHelper.FOLDER;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent;
+import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Generation;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
 import com.tagtraum.perf.gcviewer.model.GCModel;
 import org.junit.Test;
@@ -26,23 +25,29 @@ private GCModel getGCModelFromLogFile(String fileName) throws IOException {
     public void parseGcDefaults() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-parallel-gc-defaults.txt");
         assertThat("size", model.size(), is(11));
-        assertThat("amount gc events", model.getGcEventPauses().size(), is(1));
-        assertThat("amount full gc events", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of gc event types", model.getGcEventPauses().size(), is(1));
+        assertThat("amount of gc events", model.getGCPause().getN(), is(5));
+        assertThat("amount of full gc event types", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of full gc events", model.getFullGCPause().getN(), is(6));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(0));
 
         AbstractGCEvent<?> event1 = model.get(0);
-        assertThat("event1 type", event1.getTypeAsString(), startsWith(Type.UJL_PAUSE_YOUNG.getName()));
-        assertThat("event1 pause", event1.getPause(), closeTo(0.006868, 0.00001));
-        assertThat("event1 heap before", event1.getPreUsed(), is(1024 * 32));
-        assertThat("event1 heap after", event1.getPostUsed(), is(1024 * 29));
-        assertThat("event1 total heap", event1.getTotal(), is(1024 * 123));
+        UnittestHelper.testMemoryPauseEvent(event1,
+                "pause young",
+                Type.UJL_PAUSE_YOUNG,
+                0.006868,
+                1024 * 32, 1024 * 29, 1024 * 123,
+                Generation.YOUNG,
+                false);
 
         AbstractGCEvent<?> event2 = model.get(2);
-        assertThat("event2 type", event2.getTypeAsString(), startsWith(Type.UJL_PAUSE_FULL.getName()));
-        assertThat("event2 pause", event2.getPause(), closeTo(0.013765, 0.00001));
-        assertThat("event2 heap before", event2.getPreUsed(), is(1024 * 62));
-        assertThat("event2 heap after", event2.getPostUsed(), is(1024 * 61));
-        assertThat("event2 total heap", event2.getTotal(), is(1024 * 123));
+        UnittestHelper.testMemoryPauseEvent(event2,
+                "pause full",
+                Type.UJL_PAUSE_FULL,
+                0.013765,
+                1024 * 62, 1024 * 61, 1024 * 123,
+                Generation.ALL,
+                true);
     }
 
     @Test
@@ -50,27 +55,39 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-parallel-gc-all,safepoint,os+cpu.txt");
         assertThat("size", model.size(), is(8));
         assertThat("amount of STW GC pause types", model.getGcEventPauses().size(), is(1));
+        assertThat("amount of gc events", model.getGCPause().getN(), is(4));
         assertThat("amount of STW Full GC pause types", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of full gc events", model.getFullGCPause().getN(), is(4));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(0));
 
         AbstractGCEvent<?> event1 = model.get(0);
-        assertThat("event1 type", event1.getTypeAsString(), startsWith(Type.UJL_PAUSE_YOUNG.getName()));
-        assertThat("event1 pause", event1.getPause(), closeTo(0.008112, 0.00001));
-        assertThat("event1 heap before", event1.getPreUsed(), is(1024 * 32));
-        assertThat("event1 heap after", event1.getPostUsed(), is(1024 * 29));
-        assertThat("event1 total heap", event1.getTotal(), is(1024 * 123));
+        UnittestHelper.testMemoryPauseEvent(event1,
+                "pause young",
+            Type.UJL_PAUSE_YOUNG,
+            0.008112,
+            1024 * 32, 1024 * 29, 1024 * 123,
+            Generation.YOUNG,
+            false);
 
         // GC(6) Pause Full (Ergonomics)
         AbstractGCEvent<?> event2 = model.get(6);
-        assertThat("event2 type", event2.getTypeAsString(), startsWith(Type.UJL_PAUSE_FULL.getName()));
-        assertThat("event2 pause", event2.getPause(), closeTo(0.008792, 0.00001));
-        assertThat("event2 timestamp", event2.getTimestamp(), closeTo(0.321, 0.0001));
+        UnittestHelper.testMemoryPauseEvent(event2,
+                "pause full",
+                Type.UJL_PAUSE_FULL,
+                0.008792,
+                1024 * 95, 1024 * 31, 1024 * 123,
+                Generation.ALL,
+                true);
 
         // GC(7) Pause Young (Allocation Failure)
         AbstractGCEvent<?> event3 = model.get(7);
-        assertThat("event3 type", event3.getTypeAsString(), startsWith(Type.UJL_PAUSE_YOUNG.getName()));
-        assertThat("event3 pause", event3.getPause(), closeTo(0.005794, 0.00001));
-        assertThat("event3 timestamp", event3.getTimestamp(), closeTo(0.330, 0.0001));
+        UnittestHelper.testMemoryPauseEvent(event3,
+                "pause young 2",
+                Type.UJL_PAUSE_YOUNG,
+                0.005794,
+                1024 * 63, 1024 * 63, 1024 * 123,
+                Generation.YOUNG,
+                false);
     }
 
 }
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
index 1140c69b..9698cd89 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLSerial.java
@@ -31,8 +31,10 @@ private GCModel getGCModelFromLogFile(String fileName) throws IOException {
     public void parseGcDefaults() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-serial-gc-defaults.txt");
         assertThat("size", model.size(), is(11));
-        assertThat("amount gc events", model.getGcEventPauses().size(), is(1));
-        assertThat("amount full gc events", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of gc event types", model.getGcEventPauses().size(), is(1));
+        assertThat("amount of gc events", model.getGCPause().getN(), is(8));
+        assertThat("amount of full gc events", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of full gc events", model.getFullGCPause().getN(), is(3));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(0));
 
         AbstractGCEvent<?> event1 = model.get(0);
@@ -41,6 +43,7 @@ public void parseGcDefaults() throws Exception {
         assertThat("event1 heap before", event1.getPreUsed(), is(1024 * 25));
         assertThat("event1 heap after", event1.getPostUsed(), is(1024 * 23));
         assertThat("event1 total heap", event1.getTotal(), is(1024 * 92));
+        assertThat("event1 not isFull", event1.isFull(), is(false));
 
         AbstractGCEvent<?> event2 = model.get(2);
         assertThat("event2 type", event2.getTypeAsString(), startsWith(Type.UJL_PAUSE_FULL.getName()));
@@ -48,6 +51,7 @@ public void parseGcDefaults() throws Exception {
         assertThat("event2 heap before", event2.getPreUsed(), is(1024 * 74));
         assertThat("event2 heap after", event2.getPostUsed(), is(1024 * 10));
         assertThat("event2 total heap", event2.getTotal(), is(1024 * 92));
+        assertThat("event2 isFull", event2.isFull(), is(true));
 
         // gc log says GC(10) for this event
         AbstractGCEvent<?> event3 = model.get(9);
@@ -63,7 +67,9 @@ public void parseGcAllSafepointOsCpu() throws Exception {
         GCModel model = getGCModelFromLogFile("sample-ujl-serial-gc-all,safepoint,os+cpu.txt");
         assertThat("size", model.size(), is(4));
         assertThat("amount of STW GC pause types", model.getGcEventPauses().size(), is(1));
+        assertThat("amount of STW GC pauses", model.getGCPause().getN(), is(3));
         assertThat("amount of STW Full GC pause types", model.getFullGcEventPauses().size(), is(1));
+        assertThat("amount of STW Full GC pauses", model.getFullGCPause().getN(), is(1));
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(0));
 
         AbstractGCEvent<?> event1 = model.get(0);
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
index f5afcf24..8c2fa449 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/imp/TestDataReaderUJLShenandoah.java
@@ -15,6 +15,7 @@
 import com.tagtraum.perf.gcviewer.model.ConcurrentGCEvent;
 import com.tagtraum.perf.gcviewer.model.GCEvent;
 import com.tagtraum.perf.gcviewer.model.GCModel;
+import com.tagtraum.perf.gcviewer.util.DateHelper;
 import org.junit.Test;
 
 /**
@@ -108,10 +109,10 @@ public void parseAggressiveHeuristics() throws Exception {
         assertThat("amount of concurrent pause types", model.getConcurrentEventPauses().size(), is(5));
 
         GCEvent event = (GCEvent) model.get(0);
-        assertThat("type", event.getTypeAsString(), is(AbstractGCEvent.Type.SHEN_STW_INIT_MARK.toString()));
+        assertThat("type", event.getTypeAsString(), is(AbstractGCEvent.Type.UJL_SHEN_INIT_MARK.toString()));
 
         ConcurrentGCEvent event2 = (ConcurrentGCEvent) model.get(1);
-        assertThat("type", event2.getTypeAsString(), is(AbstractGCEvent.Type.SHEN_CONCURRENT_CONC_MARK.toString()));
+        assertThat("type", event2.getTypeAsString(), is(AbstractGCEvent.Type.UJL_SHEN_CONCURRENT_CONC_MARK.toString()));
         assertThat("preUsed heap size", event2.getPreUsed(), is(90 * 1024));
         assertThat("postUsed heap size", event2.getPostUsed(), is(90 * 1024));
         assertThat("total heap size", event2.getTotal(), is(128 * 1024));
@@ -160,16 +161,16 @@ public void parseDateTimeStamps() throws Exception {
 
         GCEvent event = (GCEvent) model.get(0);
         assertThat("datestamp", event.getDatestamp(), is(ZonedDateTime.parse("2017-08-30T23:22:47.357+0300",
-                AbstractDataReaderSun.DATE_TIME_FORMATTER)));
+                DateHelper.DATE_TIME_FORMATTER)));
         assertThat("timestamp", event.getTimestamp(), is(0.0));
-        assertThat("type", event.getTypeAsString(), is(AbstractGCEvent.Type.SHEN_STW_INIT_MARK.toString()));
+        assertThat("type", event.getTypeAsString(), is(AbstractGCEvent.Type.UJL_SHEN_INIT_MARK.toString()));
         assertThat("generation", event.getGeneration(), is(AbstractGCEvent.Generation.TENURED));
 
         ConcurrentGCEvent event2 = (ConcurrentGCEvent) model.get(1);
         assertThat("datestamp", event.getDatestamp(), is(ZonedDateTime.parse("2017-08-30T23:22:47.357+0300",
-                AbstractDataReaderSun.DATE_TIME_FORMATTER)));
+                DateHelper.DATE_TIME_FORMATTER)));
         assertThat("timestamp", event2.getTimestamp(), closeTo(0.003, 0.001));
-        assertThat("type", event2.getTypeAsString(), is(AbstractGCEvent.Type.SHEN_CONCURRENT_CONC_MARK.toString()));
+        assertThat("type", event2.getTypeAsString(), is(AbstractGCEvent.Type.UJL_SHEN_CONCURRENT_CONC_MARK.toString()));
         assertThat("preUsed heap size", event2.getPreUsed(), is(90 * 1024));
         assertThat("postUsed heap size", event2.getPostUsed(), is(90 * 1024));
         assertThat("total heap size", event2.getTotal(), is(128 * 1024));
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/model/TestGcEvent.java b/src/test/java/com/tagtraum/perf/gcviewer/model/TestGcEvent.java
index 6ccb8cfe..79c75f10 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/model/TestGcEvent.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/model/TestGcEvent.java
@@ -1,12 +1,14 @@
 package com.tagtraum.perf.gcviewer.model;
 
-import static org.junit.Assert.*;
-
-import org.junit.Before;
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.ExtendedType;
 import com.tagtraum.perf.gcviewer.model.AbstractGCEvent.Type;
+import org.hamcrest.Matchers;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Tests for class {@link GCEvent}.
@@ -84,4 +86,15 @@ public void testGetInferredTenuredGcEvent() {
         assertEquals("pause", 0.0543079, tenured.getPause(), 0.000001);
     }
 
+    @Test
+    public void testCloneAndMerge() throws Exception {
+        // 87.707: [GC 87.707: [DefNew: 139904K->5655K(157376K), 0.0543079 secs] 194540K->60292K(506944K), 0.0544020 secs] [Times: user=0.03 sys=0.02, real=0.06 secs]
+        // 83.403: [Full GC 83.403: [Tenured: 38156K->54636K(349568K), 0.6013150 secs] 141564K->54636K(506944K), [Perm : 73727K->73727K(73728K)], 0.6014256 secs] [Times: user=0.58 sys=0.00, real=0.59 secs]
+        GCEvent detailEvent1 = new GCEvent(0.01, 100, 90, 1000, 0.25, Type.G1_YOUNG);
+        GCEvent detailEvent2 = new GCEvent(0.01, 500, 200, 1000, 0.29, Type.TENURED);
+        GCEvent clonedEvent = detailEvent1.cloneAndMerge(detailEvent2);
+        assertThat("name", clonedEvent.getTypeAsString(), Matchers.equalTo("GC pause (young)+Tenured"));
+        assertThat("heap before", clonedEvent.getPreUsed(), Matchers.is(100 + 500));
+    }
+
 }
diff --git a/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-g1-gc-all,safepoint,os+cpu-to-space-exhausted.txt b/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-g1-gc-all,safepoint,os+cpu-to-space-exhausted.txt
new file mode 100644
index 00000000..b2f9e9d6
--- /dev/null
+++ b/src/test/resources/openjdk/unified-jvm-logging/sample-ujl-g1-gc-all,safepoint,os+cpu-to-space-exhausted.txt
@@ -0,0 +1,15 @@
+[0.318s][info][gc,start      ] GC(12) Pause Young (G1 Evacuation Pause)
+[0.318s][info][gc,task       ] GC(12) Using 4 workers of 4 for evacuation
+[0.321s][info][gc            ] GC(12) To-space exhausted
+[0.321s][info][gc,phases     ] GC(12)   Pre Evacuate Collection Set: 0.0ms
+[0.321s][info][gc,phases     ] GC(12)   Evacuate Collection Set: 1.9ms
+[0.321s][info][gc,phases     ] GC(12)   Post Evacuate Collection Set: 0.6ms
+[0.321s][info][gc,phases     ] GC(12)   Other: 0.1ms
+[0.321s][info][gc,heap       ] GC(12) Eden regions: 1->0(1)
+[0.321s][info][gc,heap       ] GC(12) Survivor regions: 1->1(1)
+[0.321s][info][gc,heap       ] GC(12) Old regions: 13->14
+[0.321s][info][gc,heap       ] GC(12) Humongous regions: 0->0
+[0.321s][info][gc,metaspace  ] GC(12) Metaspace: 3648K->3648K(1056768K)
+[0.321s][info][gc            ] GC(12) Pause Young (G1 Evacuation Pause) 116M->119M(128M) 2.717ms
+[0.321s][info][gc,cpu        ] GC(12) User=0.00s Sys=0.00s Real=0.00s
+[0.321s][info][safepoint     ] Total time for which application threads were stopped: 0.0027879 seconds, Stopping threads took: 0.0000093 seconds

From 733442027b0b81c3c14e2e8ef944bd1e2ab72a31 Mon Sep 17 00:00:00 2001
From: chewiebug <jwu@gmx.ch>
Date: Sun, 25 Feb 2018 18:35:16 +0100
Subject: [PATCH 3/4] fix unittests on case sensitive file systems

---
 src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java    | 2 +-
 .../perf/gcviewer/util/TestHttpUrlConnectionHelper.java         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
index c916f4c6..5e1375cb 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/UnittestHelper.java
@@ -35,7 +35,7 @@ public enum FOLDER {
         IBM("ibm"),
         JROCKIT("jrockit"),
         OPENJDK(FOLDER_OPENJDK),
-        OPENJDK_UJL(OPENJDK + File.separator + "unified-jvm-logging"),
+        OPENJDK_UJL(OPENJDK.getFolderName() + File.separator + "unified-jvm-logging"),
         HTTP("http");
 
         private String folderName;
diff --git a/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java b/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
index 74d9ef56..5ea479e9 100644
--- a/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
+++ b/src/test/java/com/tagtraum/perf/gcviewer/util/TestHttpUrlConnectionHelper.java
@@ -32,7 +32,7 @@ public class TestHttpUrlConnectionHelper {
     private static final String SAMPLE_GCLOG_SUN1_6_0 = "SampleSun1_6_0PrintHeapAtGC.txt";
     private static final String SAMPLE_GCLOG_SUN1_6_0_GZ = SAMPLE_GCLOG_SUN1_6_0 + ".gz";  
     
-    private static final String PARENT_PATH = "src/test/resources/" + FOLDER.OPENJDK + "/";
+    private static final String PARENT_PATH = "src/test/resources/" + FOLDER.OPENJDK.getFolderName() + "/";
     private static final Charset UTF8 = StandardCharsets.UTF_8;
 
     private ByteArrayInputStream create404InputStream() {

From 54d504206a6d77c4264fc9e66c17201315360c36 Mon Sep 17 00:00:00 2001
From: chewiebug <jwu@gmx.ch>
Date: Sun, 25 Feb 2018 18:59:15 +0100
Subject: [PATCH 4/4] update javadoc comments

---
 .../ctrl/GCModelLoaderGroupTracker.java       |  2 ++
 .../ctrl/impl/ViewMenuController.java         |  2 +-
 .../gcviewer/imp/AbstractDataReaderSun.java   |  4 +++-
 .../perf/gcviewer/imp/DataReaderFacade.java   |  8 +++----
 .../gcviewer/imp/DataReaderIBMi5OS1_4_2.java  |  3 ++-
 .../perf/gcviewer/model/AbstractGCEvent.java  |  2 +-
 .../util/HttpUrlConnectionHelper.java         | 21 +++++++++----------
 .../gcviewer/view/GCViewerGuiMenuBar.java     |  2 +-
 .../view/StayOpenCheckBoxMenuItem.java        |  9 ++++++++
 .../gcviewer/view/model/GCResourceGroup.java  |  1 -
 10 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/src/main/java/com/tagtraum/perf/gcviewer/ctrl/GCModelLoaderGroupTracker.java b/src/main/java/com/tagtraum/perf/gcviewer/ctrl/GCModelLoaderGroupTracker.java
index c534d174..66e42944 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/ctrl/GCModelLoaderGroupTracker.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/ctrl/GCModelLoaderGroupTracker.java
@@ -13,6 +13,7 @@
   */
 public interface GCModelLoaderGroupTracker extends PropertyChangeListener {
     /**
+     * @param listener The PropertyChangeListener to be added
      * @see java.beans.PropertyChangeSupport#addPropertyChangeListener(java.beans.PropertyChangeListener)
      */
     void addPropertyChangeListener(PropertyChangeListener listener);
@@ -36,6 +37,7 @@ public interface GCModelLoaderGroupTracker extends PropertyChangeListener {
     void propertyChange(PropertyChangeEvent evt);
 
     /**
+     * @param listener The PropertyChangeListener to be removed
      * @see java.beans.PropertyChangeSupport#removePropertyChangeListener(java.beans.PropertyChangeListener)
      */
     void removePropertyChangeListener(PropertyChangeListener listener);
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/ctrl/impl/ViewMenuController.java b/src/main/java/com/tagtraum/perf/gcviewer/ctrl/impl/ViewMenuController.java
index 29825926..dd7f11d8 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/ctrl/impl/ViewMenuController.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/ctrl/impl/ViewMenuController.java
@@ -24,7 +24,7 @@ public class ViewMenuController implements ActionListener, PropertyChangeListene
     private GCViewerGui gui;
 
     /**
-     * @param gui
+     * @param gui gui to listen for actions
      */
     public ViewMenuController(GCViewerGui gui) {
         this.gui = gui;
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
index b7889dbe..3e57c6e0 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/AbstractDataReaderSun.java
@@ -55,7 +55,9 @@ public abstract class AbstractDataReaderSun extends AbstractDataReader {
     protected GcLogType gcLogType;
 
     /**
-     * Create an instance of this class passing an inputStream an the type of the logfile.
+     * Create an instance of this class passing an inputStream and the type of the logfile.
+     *
+     * @param gcResource information about the resource to be parsed
      * @param in inputstream to the log file
      * @param gcLogType type of the logfile
      * @throws UnsupportedEncodingException if ASCII is not supported
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderFacade.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderFacade.java
index 4fd5c764..cb944ca4 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderFacade.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderFacade.java
@@ -85,7 +85,7 @@ public GCModel loadModel(GCResource gcResource) throws DataReaderException {
      *
      * @param gcResource the {@link GcResourceSeries} to load
      * @return a {@link GCModel} containing all events found in the given {@link GCResource}s that were readable
-     * @throws DataReaderException
+     * @throws DataReaderException thrown in case of some parser failure
      */
     protected GCModel loadModelFromSeries(GcResourceSeries gcResource) throws DataReaderException {
         GcSeriesLoader seriesLoader = new GcSeriesLoader(this);
@@ -106,12 +106,12 @@ private GCModel readModel(GcResourceFile gcResource) throws IOException {
         InputStream in = null;
         try {
             if (url.getProtocol().startsWith("http")) {
-                AtomicLong cl = new AtomicLong();
+                AtomicLong atomicContentLength = new AtomicLong();
                 URLConnection conn = url.openConnection();
                 in = HttpUrlConnectionHelper.openInputStream((HttpURLConnection) conn,
                         HttpUrlConnectionHelper.GZIP,
-                        cl);
-                contentLength = cl.get();
+                        atomicContentLength);
+                contentLength = atomicContentLength.get();
             }
             else {
                 in = url.openStream();
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderIBMi5OS1_4_2.java b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderIBMi5OS1_4_2.java
index c24e123e..a5f5e834 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderIBMi5OS1_4_2.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/imp/DataReaderIBMi5OS1_4_2.java
@@ -27,8 +27,9 @@ public class DataReaderIBMi5OS1_4_2 extends AbstractDataReader {
 
     /**
      * Constructor for the IBM i5/OS GC reader.
+     * @param gcResource information about the resource to be parsed
      * @param in InputStream delivering the GC data
-     * @throws UnsupportedEncodingException
+     * @throws UnsupportedEncodingException thrown in case the desired encoding is not supported
      */
     public DataReaderIBMi5OS1_4_2(GCResource gcResource, InputStream in) throws UnsupportedEncodingException {
         super(gcResource, in);
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
index 4ced53e8..a43abc64 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/model/AbstractGCEvent.java
@@ -669,7 +669,7 @@ public String toString() {
      *     <li><code>GC</code>: just the name of the event type</li>
      *     <li><code>PAUSE</code>: length of a pause</li>
      *     <li><code>DURATION</code>: cycle time of a (usually concurrent) event</li>
-     *     <li><code>MEMORY</code>: information about heap changes</li></li>
+     *     <li><code>MEMORY</code>: information about heap changes</li>
      *     <li><code>REGION</code>: information about number of regions used (only G1 up to now)</li>
      * </ul>
      */
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/util/HttpUrlConnectionHelper.java b/src/main/java/com/tagtraum/perf/gcviewer/util/HttpUrlConnectionHelper.java
index d6f13234..fb4a9778 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/util/HttpUrlConnectionHelper.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/util/HttpUrlConnectionHelper.java
@@ -96,15 +96,14 @@ private static String readAndCloseErrorStream(InputStream in,
     /**
      *  Sets request properties, connects and opens the input stream depending on the HTTP response.
      *
-     *  @param httpConn            The HTTP connection
-     *  @param acceptEncoding  Content-encoding (gzip,defate or null)
+     *  @param httpConn The HTTP connection
+     *  @param acceptEncoding Content-encoding (gzip, deflate or null)
+     *  @param contentLength length of content (output parameter)
      *  @return The input stream
      *  @throws IOException if problem occured.
      */
-    public static InputStream openInputStream(HttpURLConnection httpConn,
-            String acceptEncoding,
-            AtomicLong cl)
-                    throws IOException {
+    public static InputStream openInputStream(HttpURLConnection httpConn, String acceptEncoding, AtomicLong contentLength)
+            throws IOException {
 
         // set request properties
         httpConn.setRequestProperty(ACCEPT_ENCODING, acceptEncoding);
@@ -113,20 +112,20 @@ public static InputStream openInputStream(HttpURLConnection httpConn,
         // from here we're reading the server's response
         String contentEncoding = httpConn.getContentEncoding();
         String contentType = httpConn.getContentType();
-        long contentLength = httpConn.getContentLengthLong();
+        long contentLengthLong = httpConn.getContentLengthLong();
         long lastModified = httpConn.getLastModified();
-        LOGGER.log(Level.INFO, "Reading " + (contentLength < 0L
+        LOGGER.log(Level.INFO, "Reading " + (contentLengthLong < 0L
                  ? "?"
-                 : Long.toString(contentLength) ) + " bytes from " + httpConn.getURL() +
+                 : Long.toString(contentLengthLong) ) + " bytes from " + httpConn.getURL() +
                    "; contentType = " + contentType +
                    "; contentEncoding = " + contentEncoding +
                    "; last modified = " + (lastModified <= 0L ? "-" : new Date(lastModified).toString()));
 
         final int responseCode = httpConn.getResponseCode();
         if (responseCode/100 == 2) {
-        	if (cl != null) {
+        	if (contentLength != null) {
         		// abuse of AtomicLong, but I need a pointer to long (or FileInformation)
-        		cl.set(contentLength);
+        		contentLength.set(contentLengthLong);
         	}
         } else {
             String responseMessage = httpConn.getResponseMessage();
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/view/GCViewerGuiMenuBar.java b/src/main/java/com/tagtraum/perf/gcviewer/view/GCViewerGuiMenuBar.java
index 8d6ac43d..94a0ccd8 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/view/GCViewerGuiMenuBar.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/view/GCViewerGuiMenuBar.java
@@ -120,7 +120,7 @@ public void addToWindowMenuGroup(JCheckBoxMenuItem menuItem) {
     
     /**
      * Remove a menuItem from the window menu including removal of the group. 
-     * @param menuItem
+     * @param menuItem menuItem to be removed
      */
     public void removeFromWindowMenuGroup(JMenuItem menuItem) {
         windowMenu.remove(menuItem);
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/view/StayOpenCheckBoxMenuItem.java b/src/main/java/com/tagtraum/perf/gcviewer/view/StayOpenCheckBoxMenuItem.java
index 86ac6e08..bff4342f 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/view/StayOpenCheckBoxMenuItem.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/view/StayOpenCheckBoxMenuItem.java
@@ -38,6 +38,7 @@ public StayOpenCheckBoxMenuItem() {
     }
 
     /**
+     * @param a action, where properties are taken from to create MenuItem
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(Action)
      */
     public StayOpenCheckBoxMenuItem(Action a) {
@@ -45,6 +46,7 @@ public StayOpenCheckBoxMenuItem(Action a) {
     }
 
     /**
+     * @param icon icon for menu item
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(Icon)
      */
     public StayOpenCheckBoxMenuItem(Icon icon) {
@@ -52,6 +54,7 @@ public StayOpenCheckBoxMenuItem(Icon icon) {
     }
 
     /**
+     * @param text text for menu item
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(String)
      */
     public StayOpenCheckBoxMenuItem(String text) {
@@ -59,6 +62,8 @@ public StayOpenCheckBoxMenuItem(String text) {
     }
 
     /**
+     * @param text text for menu item
+     * @param selected initial state of checkbox
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(String, boolean)
      */
     public StayOpenCheckBoxMenuItem(String text, boolean selected) {
@@ -66,6 +71,8 @@ public StayOpenCheckBoxMenuItem(String text, boolean selected) {
     }
 
     /**
+     * @param text text for menu item
+     * @param icon icon for menu item
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(String, Icon)
      */
     public StayOpenCheckBoxMenuItem(String text, Icon icon) {
@@ -73,6 +80,8 @@ public StayOpenCheckBoxMenuItem(String text, Icon icon) {
     }
 
     /**
+     * @param text text for menu item
+     * @param selected initial state for checkbox
      * @see JCheckBoxMenuItem#JCheckBoxMenuItem(String, Icon, boolean)
      */
     public StayOpenCheckBoxMenuItem(String text, Icon icon, boolean selected) {
diff --git a/src/main/java/com/tagtraum/perf/gcviewer/view/model/GCResourceGroup.java b/src/main/java/com/tagtraum/perf/gcviewer/view/model/GCResourceGroup.java
index 07bd9519..98529212 100644
--- a/src/main/java/com/tagtraum/perf/gcviewer/view/model/GCResourceGroup.java
+++ b/src/main/java/com/tagtraum/perf/gcviewer/view/model/GCResourceGroup.java
@@ -16,7 +16,6 @@
 
 /**
  * <p>Holds a group of resource names (those displayed in the same GCDocument).</p>
- * <p>
  * <p>This class was refactored from "URLSet".</p>
  *
  * @author <a href="mailto:gcviewer@gmx.ch">Joerg Wuethrich</a>