Fix race condition for ApplicationEventListeningMessageProducer

The `ContextStoppedEvent` and `ContextClosedEvent` are emitted when the
application context is not in an active state anymore.
Therefore, dispatching those events into beans (`MessageChannel` in our case)
is not what possible to handle because endpoints are stopped (or destroyed)

* Fix `ApplicationEventListeningMessageProducer` to ignore `ContextStoppedEvent` and `ContextClosedEvent`
altogether for output channel of `AbstractMessageChannel`.
The warning we emit in that case should be enough to indicate what is going on and what could be done
to mitigate situation with custom `MessageChannel` implementation.
* Improve error message for the `MessageDispatchingException` in the `AbstractMessageChannel.assertApplicationRunning()`
to indicate what exactly channel is in the problem.

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/channel/AbstractMessageChannel.java

@@ -371,11 +371,12 @@ private void assertApplicationRunning(Message<?> message) {
 		if (!this.applicationRunning) {
 			throw new MessageDispatchingException(message,
 					"""
-							The application context is not ready to dispatch messages. \
+							The application context is not ready (or stopped) to dispatch messages to '%s' channel. \
 							It has to be refreshed or started first. \
 							Also, messages must not be emitted from initialization phase, \
 							like 'afterPropertiesSet()', '@PostConstruct' or bean definition methods. \
-							Consider to use 'SmartLifecycle.start()' instead.""");
+							Consider to use 'SmartLifecycle.start()' instead."""
+							.formatted(getComponentName()));
 		}
 	}
 

spring-integration-core/src/test/java/org/springframework/integration/bus/ApplicationContextMessageBusTests.java

@@ -76,6 +76,7 @@ public void endpointRegistrationWithInputChannelReference() throws ClassNotFound
 						ClassUtils.forName(
 								IntegrationContextUtils.BASE_PACKAGE + ".config.ApplicationRunningController", null)));
 		QueueChannel sourceChannel = new QueueChannel();
+		sourceChannel.setBeanName("sourceChannel");
 		sourceChannel.setApplicationContext(this.context);
 		QueueChannel targetChannel = new QueueChannel();
 		this.context.registerChannel("sourceChannel", sourceChannel);
@@ -84,7 +85,8 @@ public void endpointRegistrationWithInputChannelReference() throws ClassNotFound
 				.setReplyChannelName("targetChannel").build();
 		assertThatExceptionOfType(MessageDispatchingException.class)
 				.isThrownBy(() -> sourceChannel.send(message))
-				.withMessageStartingWith("The application context is not ready to dispatch messages.");
+				.withMessageStartingWith(
+						"The application context is not ready (or stopped) to dispatch messages to 'sourceChannel'");
 		AbstractReplyProducingMessageHandler handler = new AbstractReplyProducingMessageHandler() {
 
 			@Override
@@ -106,7 +108,8 @@ public Object handleRequestMessage(Message<?> message) {
 
 		assertThatExceptionOfType(MessageDispatchingException.class)
 				.isThrownBy(() -> sourceChannel.send(message))
-				.withMessageStartingWith("The application context is not ready to dispatch messages.");
+				.withMessageStartingWith(
+						"The application context is not ready (or stopped) to dispatch messages to 'sourceChannel'");
 	}
 
 	@Test

spring-integration-event/src/main/java/org/springframework/integration/event/inbound/ApplicationEventListeningMessageProducer.java

@@ -114,23 +114,24 @@ public void onApplicationEvent(ApplicationEvent event) {
 
 			if (contextFinished && getRequiredOutputChannel() instanceof AbstractMessageChannel) {
 				logger.warn("Messages for 'ContextStoppedEvent' or 'ContextClosedEvent' cannot be dispatched " +
-						"via 'AbstractMessageChannel' beans: the application context is in the finished state." +
+						"via 'AbstractMessageChannel' beans: the application context is in the finished state. " +
 						"Consider to use custom 'MessageChannel' implementation without dispatching logic.");
 			}
-
-			if (event.getSource() instanceof Message<?> message) {
-				sendMessage(message);
-			}
 			else {
-				Message<?> message;
-				Object result = extractObjectToSend(event);
-				if (result instanceof Message) {
-					message = (Message<?>) result;
+				if (event.getSource() instanceof Message<?> message) {
+					sendMessage(message);
 				}
 				else {
-					message = getMessageBuilderFactory().withPayload(result).build();
+					Message<?> message;
+					Object result = extractObjectToSend(event);
+					if (result instanceof Message) {
+						message = (Message<?>) result;
+					}
+					else {
+						message = getMessageBuilderFactory().withPayload(result).build();
+					}
+					sendMessage(message);
 				}
-				sendMessage(message);
 			}
 		}
 	}