GH-2817: KafkaTemplate: No double error timers (#2823)

* GH-2817: KafkaTemplate: No double error timers

Fixes #2817

An observation in `KafkaTemplate` can be marked with error from a `Callback`.
Then `Future` is evaluated and its exception is thrown back to the `observeSend()`.
Here this exception is caught and reported to the observation again.
This creates a second timer in the Micrometer, but with different error tag

* Check for error presence in the `observeSend()` `catch` block and skip
second report

**Cherry-pick to `3.0.x`**

* * Fix import order for Checkstyle rule

spring-kafka/src/main/java/org/springframework/kafka/core/KafkaTemplate.java

@@ -756,8 +756,11 @@ private CompletableFuture<SendResult<K, V>> observeSend(final ProducerRecord<K,
 			return doSend(producerRecord, observation);
 		}
 		catch (RuntimeException ex) {
-			observation.error(ex);
-			observation.stop();
+			// The error is added from org.apache.kafka.clients.producer.Callback
+			if (observation.getContext().getError() == null) {
+				observation.error(ex);
+				observation.stop();
+			}
 			throw ex;
 		}
 	}
@@ -783,7 +786,7 @@ protected CompletableFuture<SendResult<K, V>> doSend(final ProducerRecord<K, V>
 		}
 		Future<RecordMetadata> sendFuture =
 				producer.send(producerRecord, buildCallback(producerRecord, producer, future, sample, observation));
-		// May be an immediate failure
+		// Maybe an immediate failure
 		if (sendFuture.isDone()) {
 			try {
 				sendFuture.get();

spring-kafka/src/test/java/org/springframework/kafka/support/micrometer/ObservationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.kafka.support.micrometer;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.awaitility.Awaitility.await;
 import static org.mockito.Mockito.mock;
 
@@ -33,6 +34,7 @@
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.clients.consumer.ConsumerRecord;
 import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.errors.InvalidTopicException;
 import org.apache.kafka.common.header.Headers;
 import org.junit.jupiter.api.Test;
 
@@ -41,6 +43,7 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
+import org.springframework.kafka.KafkaException;
 import org.springframework.kafka.annotation.EnableKafka;
 import org.springframework.kafka.annotation.KafkaListener;
 import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
@@ -81,8 +84,9 @@
 
 /**
  * @author Gary Russell
- * @since 3.0
+ * @author Artem Bilan
  *
+ * @since 3.0
  */
 @SpringJUnitConfig
 @EmbeddedKafka(topics = { "observation.testT1", "observation.testT2", "ObservationTests.testT3" })
@@ -216,6 +220,14 @@ public KeyValues getLowCardinalityKeyValues(KafkaRecordReceiverContext context)
 				.getPropertyValue(endpointRegistry.getListenerContainer("obs3"), "containers", List.class).get(0);
 		cAdmin = KafkaTestUtils.getPropertyValue(container, "listenerConsumer.kafkaAdmin", KafkaAdmin.class);
 		assertThat(cAdmin).isSameAs(config.mockAdmin);
+
+		assertThatExceptionOfType(KafkaException.class)
+				.isThrownBy(() -> template.send("wrong%Topic", "data"))
+				.withCauseExactlyInstanceOf(InvalidTopicException.class);
+
+		MeterRegistryAssert.assertThat(meterRegistry)
+				.hasTimerWithNameAndTags("spring.kafka.template", KeyValues.of("error", "InvalidTopicException"))
+				.doesNotHaveMeterWithNameAndTags("spring.kafka.template", KeyValues.of("error", "KafkaException"));
 	}
 
 	@Configuration
@@ -235,15 +247,15 @@ KafkaAdmin admin(EmbeddedKafkaBroker broker) {
 		@Bean
 		ProducerFactory<Integer, String> producerFactory(EmbeddedKafkaBroker broker) {
 			Map<String, Object> producerProps = KafkaTestUtils.producerProps(broker);
-			producerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,  broker.getBrokersAsString() + ","
+			producerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, broker.getBrokersAsString() + ","
 					+ broker.getBrokersAsString());
 			return new DefaultKafkaProducerFactory<>(producerProps);
 		}
 
 		@Bean
 		ConsumerFactory<Integer, String> consumerFactory(EmbeddedKafkaBroker broker) {
 			Map<String, Object> consumerProps = KafkaTestUtils.consumerProps("obs", "false", broker);
-			consumerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,  broker.getBrokersAsString() + ","
+			consumerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, broker.getBrokersAsString() + ","
 					+ broker.getBrokersAsString() + "," + broker.getBrokersAsString());
 			return new DefaultKafkaConsumerFactory<>(consumerProps);
 		}