Fix warnings in snippeteditor code and re-generate snippetsupport.jar

- updated line reference to actual one
- fixed deprecated warnings after Java 17 update
- fixed resource leak warnings after Java 17 update
- re-generated snippetsupport.jar

See
- #210
- #217

org.eclipse.jdt.debug.ui/Snippet Support/org/eclipse/jdt/internal/debug/ui/snippeteditor/ScrapbookMain.java

@@ -14,19 +14,22 @@
 package org.eclipse.jdt.internal.debug.ui.snippeteditor;
 
 
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.security.CodeSource;
 import java.security.ProtectionDomain;
 
 /**
  * Support class for launching a snippet evaluation.
  * <p>
- * CAUTION: This class gets compiled with target=jsr14, see scripts/buildExtraJAR.xml. Don't use URLClassLoader#close() or other post-1.4 APIs!
+ * CAUTION: This class gets compiled with target=1.7, see scripts/buildExtraJAR.xml.
  */
 public class ScrapbookMain {
 
@@ -40,25 +43,19 @@ public static void main(String[] args) {
 		while (true) {
 			try {
 				evalLoop(urls);
-			} catch (ClassNotFoundException e) {
-				return;
-			} catch (NoSuchMethodException e) {
-				return;
-			} catch (InvocationTargetException e) {
-				return;
-			} catch (IllegalAccessException e) {
+			} catch (ClassNotFoundException | NoSuchMethodException | InvocationTargetException | IllegalAccessException | IOException e) {
 				return;
 			}
 		}
 
 	}
 
-	static void evalLoop(URL[] urls) throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
-		@SuppressWarnings("resource")
-		ClassLoader cl= new URLClassLoader(urls, null);
-		Class<?> clazz= cl.loadClass("org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain1"); //$NON-NLS-1$
-		Method method= clazz.getDeclaredMethod("eval", new Class[] {Class.class}); //$NON-NLS-1$
-		method.invoke(null, new Object[] {ScrapbookMain.class});
+	static void evalLoop(URL[] urls) throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, IOException {
+		try (URLClassLoader cl = new URLClassLoader(urls, null)) {
+			Class<?> clazz = cl.loadClass(JavaSnippetEditor.SCRAPBOOK_MAIN1_TYPE);
+			Method method = clazz.getDeclaredMethod(JavaSnippetEditor.SCRAPBOOK_MAIN1_METHOD, new Class[] { Class.class });
+			method.invoke(null, new Object[] {ScrapbookMain.class});
+		}
 	}
 
 	/**
@@ -77,13 +74,13 @@ public static void nop() {
 	static URL[] getClasspath(String[] urlStrings) {
 
 		//The URL Strings MUST be properly encoded
-		//using URLEncoder...see ScrapbookLauncher for details
+		// using URLEncoder...see ScrapbookLauncher.getEncodedURL(File)
 		URL[] urls= new URL[urlStrings.length + 1];
 
 		for (int i = 0; i < urlStrings.length; i++) {
 			try {
-				urls[i + 1] = new URL(URLDecoder.decode(urlStrings[i]));
-			} catch (MalformedURLException e) {
+				urls[i + 1] = new URL(URLDecoder.decode(urlStrings[i], StandardCharsets.UTF_8.name()));
+			} catch (MalformedURLException | UnsupportedEncodingException e) {
 				return null;
 			}
 		}

org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/snippeteditor/JavaSnippetEditor.java

@@ -134,14 +134,14 @@
  */
 public class JavaSnippetEditor extends AbstractDecoratedTextEditor implements IDebugEventFilter, IEvaluationListener, IValueDetailListener {
 
-	private static final String SCRAPBOOK_MAIN1_TYPE = "org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain1"; //$NON-NLS-1$
-	private static final String SCRAPBOOK_MAIN1_METHOD = "eval"; //$NON-NLS-1$
+	static final String SCRAPBOOK_MAIN1_TYPE = "org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain1"; //$NON-NLS-1$
+	static final String SCRAPBOOK_MAIN1_METHOD = "eval"; //$NON-NLS-1$
 
 	/**
-	 * Last instruction line in org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain1.eval() 
+	 * Last instruction line in org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain1.eval()
 	 * method that corresponds to the code compiled and checked into org.eclipse.jdt.debug.ui/snippetsupport.jar
 	 */
-	private static final int SCRAPBOOK_MAIN1_LAST_LINE = 28;
+	private static final int SCRAPBOOK_MAIN1_LAST_LINE = 31;
 
 	public static final String IMPORTS_CONTEXT = "SnippetEditor.imports"; //$NON-NLS-1$
 

org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/snippeteditor/ScrapbookLauncher.java

@@ -361,11 +361,8 @@ protected URL getEncodedURL(File file) throws MalformedURLException, Unsupported
 		while (tokenizer.hasMoreElements()) {
 			encoded.append(urlDelimiter);
 			String token= tokenizer.nextToken();
-			try {
-				encoded.append(URLEncoder.encode(token, ResourcesPlugin.getEncoding()));
-			} catch (UnsupportedEncodingException e) {
-				encoded.append(URLEncoder.encode(token, "UTF-8")); //$NON-NLS-1$
-			}
+			// should use same encoding as org.eclipse.jdt.internal.debug.ui.snippeteditor.ScrapbookMain.getClasspath(String[])
+			encoded.append(URLEncoder.encode(token, "UTF-8")); //$NON-NLS-1$
 		}
 		if (file.isDirectory()) {
 			encoded.append(urlDelimiter);