Fixed event listener caching through equals/hashCode on SyntheticParameterizedType

Issue: SPR-13540

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

@@ -60,7 +60,7 @@ public abstract class AbstractApplicationEventMulticaster
 
 	private final ListenerRetriever defaultRetriever = new ListenerRetriever(false);
 
-	private final Map<ListenerCacheKey, ListenerRetriever> retrieverCache =
+	final Map<ListenerCacheKey, ListenerRetriever> retrieverCache =
 			new ConcurrentHashMap<ListenerCacheKey, ListenerRetriever>(64);
 
 	private ClassLoader beanClassLoader;
@@ -303,13 +303,13 @@ public abstract class AbstractApplicationEventMulticaster
 				return true;
 			}
 			ListenerCacheKey otherKey = (ListenerCacheKey) other;
-			return ObjectUtils.nullSafeEquals(this.eventType, otherKey.eventType) &&
-					ObjectUtils.nullSafeEquals(this.sourceType, otherKey.sourceType);
+			return (ObjectUtils.nullSafeEquals(this.eventType, otherKey.eventType) &&
+					ObjectUtils.nullSafeEquals(this.sourceType, otherKey.sourceType));
 		}
 
 		@Override
 		public int hashCode() {
-			return ObjectUtils.nullSafeHashCode(this.eventType) * 29 + ObjectUtils.nullSafeHashCode(this.sourceType);
+			return (ObjectUtils.nullSafeHashCode(this.eventType) * 29 + ObjectUtils.nullSafeHashCode(this.sourceType));
 		}
 	}
 

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

@@ -34,6 +34,7 @@ import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.BeanThatBroadcasts;
 import org.springframework.context.BeanThatListens;
+import org.springframework.context.PayloadApplicationEvent;
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.context.support.StaticApplicationContext;
@@ -101,8 +102,7 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 		multicastEvent(false, StringEventListener.class, new SmartGenericTestEvent<>(this, 123L), null);
 	}
 
-	private void multicastEvent(boolean match, Class<?> listenerType,
-			ApplicationEvent event, ResolvableType eventType) {
+	private void multicastEvent(boolean match, Class<?> listenerType, ApplicationEvent event, ResolvableType eventType) {
 		@SuppressWarnings("unchecked")
 		ApplicationListener<ApplicationEvent> listener =
 				(ApplicationListener<ApplicationEvent>) mock(listenerType);
@@ -111,7 +111,8 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 
 		if (eventType != null) {
 			smc.multicastEvent(event, eventType);
-		} else {
+		}
+		else {
 			smc.multicastEvent(event);
 		}
 		int invocation = match ? 1 : 0;
@@ -267,6 +268,31 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 		assertTrue(listener1.seenEvents.contains(event3));
 		assertTrue(listener1.seenEvents.contains(event4));
 
+		AbstractApplicationEventMulticaster multicaster = context.getBean(AbstractApplicationEventMulticaster.class);
+		assertEquals(2, multicaster.retrieverCache.size());
+
+		context.close();
+	}
+
+	@Test
+	public void listenersInApplicationContextWithPayloadEvents() {
+		StaticApplicationContext context = new StaticApplicationContext();
+		context.registerBeanDefinition("listener", new RootBeanDefinition(MyPayloadListener.class));
+		context.refresh();
+
+		MyPayloadListener listener = context.getBean("listener", MyPayloadListener.class);
+		context.publishEvent("event1");
+		context.publishEvent("event2");
+		context.publishEvent("event3");
+		context.publishEvent("event4");
+		assertTrue(listener.seenPayloads.contains("event1"));
+		assertTrue(listener.seenPayloads.contains("event2"));
+		assertTrue(listener.seenPayloads.contains("event3"));
+		assertTrue(listener.seenPayloads.contains("event4"));
+
+		AbstractApplicationEventMulticaster multicaster = context.getBean(AbstractApplicationEventMulticaster.class);
+		assertEquals(2, multicaster.retrieverCache.size());
+
 		context.close();
 	}
 
@@ -278,7 +304,7 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 		nestedChild.setInitMethodName("refresh");
 		context.registerBeanDefinition("nestedChild", nestedChild);
 		RootBeanDefinition listener1Def = new RootBeanDefinition(MyOrderedListener1.class);
-		listener1Def.setDependsOn(new String[] {"nestedChild"});
+		listener1Def.setDependsOn("nestedChild");
 		context.registerBeanDefinition("listener1", listener1Def);
 		context.refresh();
 
@@ -431,6 +457,17 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 	}
 
 
+	public static class MyPayloadListener implements ApplicationListener<PayloadApplicationEvent> {
+
+		public final Set<Object> seenPayloads = new HashSet<Object>();
+
+		@Override
+		public void onApplicationEvent(PayloadApplicationEvent event) {
+			this.seenPayloads.add(event.getPayload());
+		}
+	}
+
+
 	public static class MyNonSingletonListener implements ApplicationListener<ApplicationEvent> {
 
 		public static final Set<ApplicationEvent> seenEvents = new HashSet<ApplicationEvent>();

spring-core/src/main/java/org/springframework/core/ResolvableType.java

@@ -27,6 +27,7 @@ import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.lang.reflect.WildcardType;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.IdentityHashMap;
 import java.util.Map;
@@ -1393,8 +1394,8 @@ public class ResolvableType implements Serializable {
 		}
 
 		@Override
-		public Type[] getActualTypeArguments() {
-			return this.typeArguments;
+		public Type getOwnerType() {
+			return null;
 		}
 
 		@Override
@@ -1403,8 +1404,26 @@ public class ResolvableType implements Serializable {
 		}
 
 		@Override
-		public Type getOwnerType() {
-			return null;
+		public Type[] getActualTypeArguments() {
+			return this.typeArguments;
+		}
+
+		@Override
+		public boolean equals(Object other) {
+			if (this == other) {
+				return true;
+			}
+			if (!(other instanceof ParameterizedType)) {
+				return false;
+			}
+			ParameterizedType otherType = (ParameterizedType) other;
+			return (otherType.getOwnerType() == null && this.rawType.equals(otherType.getRawType()) &&
+					Arrays.equals(this.typeArguments, otherType.getActualTypeArguments()));
+		}
+
+		@Override
+		public int hashCode() {
+			return (this.rawType.hashCode() * 31 + Arrays.hashCode(this.typeArguments));
 		}
 	}
 

spring-core/src/main/java/org/springframework/core/ResolvableTypeProvider.java

@@ -18,11 +18,11 @@ package org.springframework.core;
 
 /**
  * Any object can implement this interface to provide its actual {@link ResolvableType}.
- * <p>
- * Such information is very useful when figuring out if the instance matches a generic
+ *
+ * <p>Such information is very useful when figuring out if the instance matches a generic
  * signature as Java does not convey the signature at runtime.
- * <p>
- * Users of this interface should be careful in complex hierarchy scenarios, especially
+ *
+ * <p>Users of this interface should be careful in complex hierarchy scenarios, especially
  * when the generic type signature of the class changes in sub-classes. It is always
  * possible to return {@code null} to fallback on a default behaviour.
  *
@@ -32,8 +32,8 @@ package org.springframework.core;
 public interface ResolvableTypeProvider {
 
 	/**
-	 * Return the {@link ResolvableType} describing this instance or {@code null} if some
-	 * sort of default should be applied instead.
+	 * Return the {@link ResolvableType} describing this instance
+	 * (or {@code null} if some sort of default should be applied instead).
 	 */
 	ResolvableType getResolvableType();