KafkaMessageListenerContainer Code Cleanup

Fixes: #3079 

* Add method consumerWakeIfNecessary() to reuse consumer.wakeIfNecessary().
* Add method getTxProducer().
* Optimize determineListenerType().
* Change OffsetMetadata type to record.

Author: Wzy19930507

Diff for: spring-kafka/src/main/java/org/springframework/kafka/listener/KafkaMessageListenerContainer.java

@@ -305,8 +305,7 @@ public boolean isContainerPaused() {
 
 	@Override
 	public boolean isPartitionPaused(TopicPartition topicPartition) {
-		return this.listenerConsumer != null && this.listenerConsumer
-				.isPartitionPaused(topicPartition);
+		return this.listenerConsumer != null && this.listenerConsumer.isPartitionPaused(topicPartition);
 	}
 
 	@Override
@@ -317,33 +316,28 @@ public boolean isInExpectedState() {
 	@Override
 	public void enforceRebalance() {
 		this.thisOrParentContainer.enforceRebalanceRequested.set(true);
-		KafkaMessageListenerContainer<K, V>.ListenerConsumer consumer = this.listenerConsumer;
-		if (consumer != null) {
-			consumer.wakeIfNecessary();
-		}
+		consumerWakeIfNecessary();
 	}
 
 	@Override
 	public void pause() {
 		super.pause();
-		KafkaMessageListenerContainer<K, V>.ListenerConsumer consumer = this.listenerConsumer;
-		if (consumer != null) {
-			consumer.wakeIfNecessary();
-		}
+		consumerWakeIfNecessary();
 	}
 
 	@Override
 	public void resume() {
 		super.resume();
-		KafkaMessageListenerContainer<K, V>.ListenerConsumer consumer = this.listenerConsumer;
-		if (consumer != null) {
-			consumer.wakeIfNecessary();
-		}
+		consumerWakeIfNecessary();
 	}
 
 	@Override
 	public void resumePartition(TopicPartition topicPartition) {
 		super.resumePartition(topicPartition);
+		consumerWakeIfNecessary();
+	}
+
+	private void consumerWakeIfNecessary() {
 		KafkaMessageListenerContainer<K, V>.ListenerConsumer consumer = this.listenerConsumer;
 		if (consumer != null) {
 			consumer.wakeIfNecessary();
@@ -422,15 +416,11 @@ private void checkAckMode(ContainerProperties containerProperties) {
 	}
 
 	private ListenerType determineListenerType(GenericMessageListener<?> listener) {
-		ListenerType listenerType = ListenerUtils.determineListenerType(listener);
-		if (listener instanceof DelegatingMessageListener) {
-			Object delegating = listener;
-			while (delegating instanceof DelegatingMessageListener<?> dml) {
-				delegating = dml.getDelegate();
-			}
-			listenerType = ListenerUtils.determineListenerType(delegating);
+		Object delegating = listener;
+		while (delegating instanceof DelegatingMessageListener<?> dml) {
+			delegating = dml.getDelegate();
 		}
-		return listenerType;
+		return ListenerUtils.determineListenerType(delegating);
 	}
 
 	@Override
@@ -1586,7 +1576,7 @@ private void fixTxOffsetsIfNeeded() {
 					this.lastCommits.forEach((tp, oamd) -> {
 						long position = this.consumer.position(tp);
 						Long saved = this.savedPositions.get(tp);
-						if (saved != null && saved.longValue() != position) {
+						if (saved != null && saved != position) {
 							this.logger.debug(() -> "Skipping TX offset correction - seek(s) have been performed; "
 									+ "saved: " + this.savedPositions + ", "
 									+ "committed: " + oamd + ", "
@@ -1609,9 +1599,7 @@ private void fixTxOffsetsIfNeeded() {
 						}
 						else {
 							this.transactionTemplate.executeWithoutResult(status -> {
-								doSendOffsets(((KafkaResourceHolder) TransactionSynchronizationManager
-										.getResource(this.kafkaTxManager.getProducerFactory()))
-										.getProducer(), toFix);
+								doSendOffsets(getTxProducer(), toFix);
 							});
 						}
 					}
@@ -2195,9 +2183,7 @@ private void invokeBatchListenerInTx(final ConsumerRecords<K, V> records,
 					@Override
 					public void doInTransactionWithoutResult(TransactionStatus s) {
 						if (ListenerConsumer.this.kafkaTxManager != null) {
-							ListenerConsumer.this.producer = ((KafkaResourceHolder) TransactionSynchronizationManager
-									.getResource(ListenerConsumer.this.kafkaTxManager.getProducerFactory()))
-										.getProducer(); // NOSONAR nullable
+							ListenerConsumer.this.producer = getTxProducer();
 						}
 						RuntimeException aborted = doInvokeBatchListener(records, recordList);
 						if (aborted != null) {
@@ -2516,7 +2502,6 @@ private void invokeRecordListener(final ConsumerRecords<K, V> records) {
 		 * Invoke the listener with each record in a separate transaction.
 		 * @param records the records.
 		 */
-		@SuppressWarnings(RAWTYPES) // NOSONAR complexity
 		private void invokeRecordListenerInTx(final ConsumerRecords<K, V> records) {
 			Iterator<ConsumerRecord<K, V>> iterator = records.iterator();
 			while (iterator.hasNext()) {
@@ -2561,9 +2546,7 @@ private void invokeInTransaction(Iterator<ConsumerRecord<K, V>> iterator, final
 				@Override
 				public void doInTransactionWithoutResult(TransactionStatus s) {
 					if (ListenerConsumer.this.kafkaTxManager != null) {
-						ListenerConsumer.this.producer = ((KafkaResourceHolder) TransactionSynchronizationManager
-								.getResource(ListenerConsumer.this.kafkaTxManager.getProducerFactory()))
-										.getProducer(); // NOSONAR
+						ListenerConsumer.this.producer = getTxProducer();
 					}
 					RuntimeException aborted = doInvokeRecordListener(cRecord, iterator);
 					if (aborted != null) {
@@ -2755,6 +2738,13 @@ private void pauseForNackSleep() {
 			this.nackSleepDurationMillis = -1;
 		}
 
+		@SuppressWarnings(RAWTYPES)
+		private Producer<?, ?> getTxProducer() {
+			return ((KafkaResourceHolder) TransactionSynchronizationManager
+					.getResource(ListenerConsumer.this.kafkaTxManager.getProducerFactory()))
+					.getProducer(); // NOSONAR
+		}
+
 		/**
 		 * Actually invoke the listener.
 		 * @param cRecord the record.
@@ -3884,20 +3874,13 @@ private Long computeBackwardWhereTo(long offset, boolean toCurrent, TopicPartiti
 	}
 
 
-	private static final class OffsetMetadata {
-
-		final Long offset; // NOSONAR
-
-		final boolean relativeToCurrent; // NOSONAR
-
-		final SeekPosition seekPosition; // NOSONAR
-
-		OffsetMetadata(Long offset, boolean relativeToCurrent, SeekPosition seekPosition) {
-			this.offset = offset;
-			this.relativeToCurrent = relativeToCurrent;
-			this.seekPosition = seekPosition;
-		}
-
+	/**
+	 * Offset metadata record.
+	 * @param offset            current offset.
+	 * @param relativeToCurrent relative to current.
+	 * @param seekPosition      seek position strategy.
+	 */
+	private record OffsetMetadata(Long offset, boolean relativeToCurrent, SeekPosition seekPosition) {
 	}
 
 	private class StopCallback implements BiConsumer<Object, Throwable> {