Suppress ClassCastException for payload type mismatch as well

Closes gh-26349

Author: jhoeller

spring-context/src/main/java/org/springframework/context/PayloadApplicationEvent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -16,18 +16,21 @@
 
 package org.springframework.context;
 
+import java.util.function.Consumer;
+
 import org.springframework.core.ResolvableType;
 import org.springframework.core.ResolvableTypeProvider;
 import org.springframework.util.Assert;
 
 /**
  * An {@link ApplicationEvent} that carries an arbitrary payload.
  *
- * <p>Mainly intended for internal use within the framework.
- *
  * @author Stephane Nicoll
+ * @author Juergen Hoeller
  * @since 4.2
  * @param <T> the payload type of the event
+ * @see ApplicationEventPublisher#publishEvent(Object)
+ * @see ApplicationListener#forPayload(Consumer)
  */
 @SuppressWarnings("serial")
 public class PayloadApplicationEvent<T> extends ApplicationEvent implements ResolvableTypeProvider {

spring-context/src/main/java/org/springframework/context/event/SimpleApplicationEventMulticaster.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -24,6 +24,7 @@
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationListener;
+import org.springframework.context.PayloadApplicationEvent;
 import org.springframework.core.ResolvableType;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ErrorHandler;
@@ -55,6 +56,9 @@ public class SimpleApplicationEventMulticaster extends AbstractApplicationEventM
 	@Nullable
 	private ErrorHandler errorHandler;
 
+	@Nullable
+	private volatile Log lazyLogger;
+
 
 	/**
 	 * Create a new SimpleApplicationEventMulticaster.
@@ -173,12 +177,18 @@ private void doInvokeListener(ApplicationListener listener, ApplicationEvent eve
 		}
 		catch (ClassCastException ex) {
 			String msg = ex.getMessage();
-			if (msg == null || matchesClassCastMessage(msg, event.getClass())) {
+			if (msg == null || matchesClassCastMessage(msg, event.getClass()) ||
+					(event instanceof PayloadApplicationEvent &&
+							matchesClassCastMessage(msg, ((PayloadApplicationEvent) event).getPayload().getClass()))) {
 				// Possibly a lambda-defined listener which we could not resolve the generic event type for
-				// -> let's suppress the exception and just log a debug message.
-				Log logger = LogFactory.getLog(getClass());
-				if (logger.isTraceEnabled()) {
-					logger.trace("Non-matching event type for listener: " + listener, ex);
+				// -> let's suppress the exception.
+				Log loggerToUse = this.lazyLogger;
+				if (loggerToUse == null) {
+					loggerToUse = LogFactory.getLog(getClass());
+					this.lazyLogger = loggerToUse;
+				}
+				if (loggerToUse.isTraceEnabled()) {
+					loggerToUse.trace("Non-matching event type for listener: " + listener, ex);
 				}
 			}
 			else {

spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -49,9 +49,11 @@ public void testEventClassWithInterface() {
 	public void testProgrammaticEventListener() {
 		List<Auditable> events = new ArrayList<>();
 		ApplicationListener<AuditablePayloadEvent<String>> listener = events::add;
+		ApplicationListener<AuditablePayloadEvent<Integer>> mismatch = (event -> event.getPayload().intValue());
 
 		ConfigurableApplicationContext ac = new GenericApplicationContext();
 		ac.addApplicationListener(listener);
+		ac.addApplicationListener(mismatch);
 		ac.refresh();
 
 		AuditablePayloadEvent<String> event = new AuditablePayloadEvent<>(this, "xyz");
@@ -63,9 +65,11 @@ public void testProgrammaticEventListener() {
 	public void testProgrammaticPayloadListener() {
 		List<String> events = new ArrayList<>();
 		ApplicationListener<PayloadApplicationEvent<String>> listener = ApplicationListener.forPayload(events::add);
+		ApplicationListener<PayloadApplicationEvent<Integer>> mismatch = ApplicationListener.forPayload(payload -> payload.intValue());
 
 		ConfigurableApplicationContext ac = new GenericApplicationContext();
 		ac.addApplicationListener(listener);
+		ac.addApplicationListener(mismatch);
 		ac.refresh();
 
 		AuditablePayloadEvent<String> event = new AuditablePayloadEvent<>(this, "xyz");