GH-9878: Fix ConcurrentModificationException in SpringIntegrationTestExecutionListener

    Fixes: gh-9878

    * return new list in MockIntegrationContext.getAutoStartupCandidates()

Signed-off-by: Alexander Hain <[email protected]>

Author: clf-ahain

spring-integration-test/src/main/java/org/springframework/integration/test/context/MockIntegrationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2024 the original author or authors.
+ * Copyright 2017-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import reactor.core.publisher.Mono;
@@ -59,6 +60,7 @@
  *
  * @author Artem Bilan
  * @author Yicheng Feng
+ * @author Alexander Hain
  *
  * @since 5.0
  *
@@ -111,21 +113,21 @@ public void afterSingletonsInstantiated() {
 	}
 
 	List<AbstractEndpoint> getAutoStartupCandidates() {
-		return this.autoStartupCandidates;
+		return Collections.unmodifiableList(this.autoStartupCandidates);
 	}
 
 	/**
 	 * Reinstate the mocked beans after execution test to their real state.
 	 * Typically, this method is used from JUnit clean up methods.
+	 *
 	 * @param beanNames the bean names to reset.
-	 * If {@code null}, all the mocked beans are reset
+	 *                  If {@code null}, all the mocked beans are reset
 	 */
 	public void resetBeans(String... beanNames) {
 		final Collection<String> names;
 		if (!ObjectUtils.isEmpty(beanNames)) {
 			names = Arrays.asList(beanNames);
-		}
-		else {
+		} else {
 			names = null;
 		}
 
@@ -142,8 +144,7 @@ public void resetBeans(String... beanNames) {
 			for (String name : beanNames) {
 				this.beans.remove(name);
 			}
-		}
-		else {
+		} else {
 			this.beans.clear();
 		}
 	}
@@ -157,14 +158,11 @@ private void resetBean(Object endpoint, Object component) {
 		}
 		if (endpoint instanceof SourcePollingChannelAdapter && component instanceof MessageSource<?>) {
 			directFieldAccessor.setPropertyValue("source", component);
-		}
-		else if (endpoint instanceof IntegrationConsumer && component instanceof MessageHandler) {
+		} else if (endpoint instanceof IntegrationConsumer && component instanceof MessageHandler) {
 			directFieldAccessor.setPropertyValue(HANDLER, component);
-		}
-		else if (endpoint instanceof ReactiveStreamsConsumer && component instanceof ReactiveMessageHandler) {
+		} else if (endpoint instanceof ReactiveStreamsConsumer && component instanceof ReactiveMessageHandler) {
 			directFieldAccessor.setPropertyValue(REACTIVE_MESSAGE_HANDLER, component);
-		}
-		else if (component instanceof Trigger) {
+		} else if (component instanceof Trigger) {
 			directFieldAccessor.setPropertyValue("trigger", component);
 		}
 		if (lifecycle != null && lifecycle.isAutoStartup()) {
@@ -176,7 +174,8 @@ else if (component instanceof Trigger) {
 	 * Replace the real {@link MessageSource} in the {@link SourcePollingChannelAdapter} bean
 	 * with provided {@link MessageSource} instance.
 	 * Can be a mock object.
-	 * @param pollingAdapterId the endpoint bean name
+	 *
+	 * @param pollingAdapterId  the endpoint bean name
 	 * @param mockMessageSource the {@link MessageSource} to replace in the endpoint bean
 	 * @see org.springframework.integration.test.mock.MockIntegration#mockMessageSource
 	 */
@@ -189,13 +188,14 @@ public void substituteMessageSourceFor(String pollingAdapterId, MessageSource<?>
 	 * with provided {@link MessageSource} instance.
 	 * Can be a mock object.
 	 * The endpoint is not started when {@code autoStartup == false}.
-	 * @param pollingAdapterId the endpoint bean name
+	 *
+	 * @param pollingAdapterId  the endpoint bean name
 	 * @param mockMessageSource the {@link MessageSource} to replace in the endpoint bean
-	 * @param autoStartup start or not the endpoint after replacing its {@link MessageSource}
+	 * @param autoStartup       start or not the endpoint after replacing its {@link MessageSource}
 	 * @see org.springframework.integration.test.mock.MockIntegration#mockMessageSource
 	 */
 	public void substituteMessageSourceFor(String pollingAdapterId, MessageSource<?> mockMessageSource,
-			boolean autoStartup) {
+										   boolean autoStartup) {
 
 		substituteComponentFor(pollingAdapterId, mockMessageSource, SourcePollingChannelAdapter.class, "source",
 				autoStartup);
@@ -206,7 +206,7 @@ public void substituteMessageHandlerFor(String consumerEndpointId, MessageHandle
 	}
 
 	public void substituteMessageHandlerFor(String consumerEndpointId, // NOSONAR - complexity
-			MessageHandler mockMessageHandler, boolean autoStartup) {
+											MessageHandler mockMessageHandler, boolean autoStartup) {
 
 		Object endpoint = this.beanFactory.getBean(consumerEndpointId, IntegrationConsumer.class);
 		if (autoStartup && endpoint instanceof Lifecycle lifecycle) {
@@ -227,15 +227,13 @@ public void substituteMessageHandlerFor(String consumerEndpointId, // NOSONAR -
 			if (targetMessageHandler instanceof MessageProducer messageProducer) {
 				MessageChannel outputChannel = messageProducer.getOutputChannel();
 				mockMessageProducer.setOutputChannel(outputChannel);
-			}
-			else {
+			} else {
 				if (mockMessageHandler instanceof MockMessageHandler) {
 					if (TestUtils.getPropertyValue(mockMessageHandler, "hasReplies", Boolean.class)) {
 						throw new IllegalStateException("The [" + mockMessageHandler + "] " +
 								"with replies can't replace simple MessageHandler [" + targetMessageHandler + "]");
 					}
-				}
-				else {
+				} else {
 					throw new IllegalStateException("The MessageProducer handler [" + mockMessageHandler + "] " +
 							"can't replace simple MessageHandler [" + targetMessageHandler + "]");
 				}
@@ -257,8 +255,9 @@ public void substituteMessageHandlerFor(String consumerEndpointId, // NOSONAR -
 
 	/**
 	 * Replace the real {@link Trigger} in the {@link AbstractPollingEndpoint} bean with provided instance.
+	 *
 	 * @param pollingEndpointId the {@link AbstractPollingEndpoint} bean id to replace
-	 * @param trigger the {@link Trigger} to set into {@link AbstractPollingEndpoint}
+	 * @param trigger           the {@link Trigger} to set into {@link AbstractPollingEndpoint}
 	 * @since 6.3
 	 */
 	public void substituteTriggerFor(String pollingEndpointId, Trigger trigger) {
@@ -268,17 +267,18 @@ public void substituteTriggerFor(String pollingEndpointId, Trigger trigger) {
 	/**
 	 * Replace the real {@link Trigger} in the {@link AbstractPollingEndpoint} bean with provided instance.
 	 * The endpoint is not started when {@code autoStartup == false}.
+	 *
 	 * @param pollingEndpointId the {@link AbstractPollingEndpoint} bean id to replace
-	 * @param trigger the {@link Trigger} to set into {@link AbstractPollingEndpoint}
-	 * @param autoStartup start or not the endpoint after replacing its {@link MessageSource}
+	 * @param trigger           the {@link Trigger} to set into {@link AbstractPollingEndpoint}
+	 * @param autoStartup       start or not the endpoint after replacing its {@link MessageSource}
 	 * @since 6.3
 	 */
 	public void substituteTriggerFor(String pollingEndpointId, Trigger trigger, boolean autoStartup) {
 		substituteComponentFor(pollingEndpointId, trigger, AbstractPollingEndpoint.class, "trigger", autoStartup);
 	}
 
 	private void substituteComponentFor(String endpointId, Object messagingComponent, Class<?> endpointClass,
-			String property, boolean autoStartup) {
+										String property, boolean autoStartup) {
 
 		Object endpoint = this.beanFactory.getBean(endpointId, endpointClass);
 		if (autoStartup && endpoint instanceof Lifecycle lifecycle) {