From 4be41e9e266f45d7502127d9cb3bbd3e5388a3be Mon Sep 17 00:00:00 2001
From: Juergen Hoeller <jhoeller@pivotal.io>
Date: Mon, 25 Feb 2019 17:18:07 +0100
Subject: [PATCH] Only use payload if it actually matches declared event type

Closes gh-22426
---
 .../ApplicationListenerMethodAdapter.java     | 18 ++---
 .../event/PayloadApplicationEventTests.java   | 72 +++++++++++++++++++
 2 files changed, 82 insertions(+), 8 deletions(-)
 create mode 100644 spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java

diff --git a/spring-context/src/main/java/org/springframework/context/event/ApplicationListenerMethodAdapter.java b/spring-context/src/main/java/org/springframework/context/event/ApplicationListenerMethodAdapter.java
index 6cbe6e0cd3..e81ff3633c 100644
--- a/spring-context/src/main/java/org/springframework/context/event/ApplicationListenerMethodAdapter.java
+++ b/spring-context/src/main/java/org/springframework/context/event/ApplicationListenerMethodAdapter.java
@@ -188,9 +188,9 @@ public class ApplicationListenerMethodAdapter implements GenericApplicationListe
 
 	/**
 	 * Resolve the method arguments to use for the specified {@link ApplicationEvent}.
-	 * <p>These arguments will be used to invoke the method handled by this instance. Can
-	 * return {@code null} to indicate that no suitable arguments could be resolved and
-	 * therefore the method should not be invoked at all for the specified event.
+	 * <p>These arguments will be used to invoke the method handled by this instance.
+	 * Can return {@code null} to indicate that no suitable arguments could be resolved
+	 * and therefore the method should not be invoked at all for the specified event.
 	 */
 	@Nullable
 	protected Object[] resolveArguments(ApplicationEvent event) {
@@ -201,13 +201,15 @@ public class ApplicationListenerMethodAdapter implements GenericApplicationListe
 		if (this.method.getParameterCount() == 0) {
 			return new Object[0];
 		}
-		if (!ApplicationEvent.class.isAssignableFrom(declaredEventType.toClass()) &&
+		Class<?> declaredEventClass = declaredEventType.toClass();
+		if (!ApplicationEvent.class.isAssignableFrom(declaredEventClass) &&
 				event instanceof PayloadApplicationEvent) {
-			return new Object[] {((PayloadApplicationEvent) event).getPayload()};
-		}
-		else {
-			return new Object[] {event};
+			Object payload = ((PayloadApplicationEvent) event).getPayload();
+			if (declaredEventClass.isInstance(payload)) {
+				return new Object[] {payload};
+			}
 		}
+		return new Object[] {event};
 	}
 
 	protected void handleResult(Object result) {
diff --git a/spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java b/spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java
new file mode 100644
index 0000000000..c9f9c17996
--- /dev/null
+++ b/spring-context/src/test/java/org/springframework/context/event/PayloadApplicationEventTests.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2002-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.event;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.PayloadApplicationEvent;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.stereotype.Component;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ */
+public class PayloadApplicationEventTests {
+
+	@Test
+	public void testEventClassWithInterface() {
+		ApplicationContext ac = new AnnotationConfigApplicationContext(Listener.class);
+		MyEventClass event = new MyEventClass<>(this, "xyz");
+		ac.publishEvent(event);
+		assertTrue(ac.getBean(Listener.class).events.contains(event));
+	}
+
+
+	public interface Auditable {
+	}
+
+
+	public static class MyEventClass<GT> extends PayloadApplicationEvent<GT> implements Auditable {
+
+		public MyEventClass(Object source, GT payload) {
+			super(source, payload);
+		}
+
+		public String toString() {
+			return "Payload: " + getPayload();
+		}
+	}
+
+
+	@Component
+	public static class Listener {
+
+		public final List<Auditable> events = new ArrayList<>();
+
+		@EventListener
+		public void onEvent(Auditable event) {
+			events.add(event);
+		}
+	}
+
+}