Revert "Manage asynchronous EventListener with replies"

This reverts commit bee1b77.

Author: snicoll

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

@@ -35,10 +35,8 @@
 import org.springframework.core.BridgeMethodResolver;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.annotation.AnnotatedElementUtils;
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.annotation.Order;
 import org.springframework.expression.EvaluationContext;
-import org.springframework.scheduling.annotation.Async;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.ReflectionUtils;
@@ -84,7 +82,6 @@ public class ApplicationListenerMethodAdapter implements GenericApplicationListe
 
 
 	public ApplicationListenerMethodAdapter(String beanName, Class<?> targetClass, Method method) {
-		validateMethod(method);
 		this.beanName = beanName;
 		this.method = method;
 		this.targetClass = targetClass;
@@ -93,14 +90,6 @@ public ApplicationListenerMethodAdapter(String beanName, Class<?> targetClass, M
 		this.methodKey = new AnnotatedElementKey(this.method, this.targetClass);
 	}
 
-	private static void validateMethod(Method method) {
-		if (method.getReturnType() != void.class &&
-				AnnotationUtils.findAnnotation(method, Async.class) != null) {
-			throw new IllegalStateException(
-					"Asynchronous @EventListener method is not allowed to return reply events: " + method);
-		}
-	}
-
 
 	/**
 	 * Initialize this instance.

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

@@ -155,19 +155,6 @@ public void methodSignatureNoEvent() {
 		failingContext.refresh();
 	}
 
-	@Test
-	public void asyncWithReplyEventListener() {
-		AnnotationConfigApplicationContext failingContext =
-				new AnnotationConfigApplicationContext();
-		failingContext.register(BasicConfiguration.class,
-				InvalidAsyncEventListener.class);
-
-		this.thrown.expect(BeanInitializationException.class);
-		this.thrown.expectMessage(InvalidAsyncEventListener.class.getName());
-		this.thrown.expectMessage("asyncCannotUseReply");
-		failingContext.refresh();
-	}
-
 	@Test
 	public void simpleReply() {
 		load(TestEventListener.class, ReplyEventListener.class);
@@ -669,17 +656,6 @@ public void cannotBeCalled(String s, Integer what) {
 		}
 	}
 
-	@Component
-	static class InvalidAsyncEventListener {
-
-		@EventListener
-		@Async
-		public Integer asyncCannotUseReply(String payload) {
-			return 42;
-		}
-
-	}
-
 
 	@Component
 	static class ReplyEventListener extends AbstractTestEventListener {
@@ -790,7 +766,6 @@ public void handleAsync(AnotherTestEvent event) {
 			this.eventCollector.addEvent(this, event);
 			this.countDownLatch.countDown();
 		}
-
 	}
 
 
@@ -894,6 +869,7 @@ public void handleString(GenericEventPojo<String> value) {
 	}
 
 
+
 	@EventListener
 	@Retention(RetentionPolicy.RUNTIME)
 	public @interface ConditionalEvent {