Polish async method execution infrastructure

In anticipation of substantive changes required to implement @Async
executor qualification, the following updates have been made to the
components and infrastructure supporting @Async functionality:

 - Fix trailing whitespace and indentation errors
 - Fix generics warnings
 - Add Javadoc where missing, update to use {@code} tags, etc.
 - Avoid NPE in AopUtils#canApply
 - Organize imports to follow conventions
 - Remove System.out.println statements from tests
 - Correct various punctuation and grammar problems

Issue: SPR-9443
Backport-Issue: SPR-6847
Backport-Commit: 3fb11870d9

org.springframework.context/src/main/java/org/springframework/scheduling/annotation/Async.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -28,13 +28,13 @@ import java.lang.annotation.Target;
  * considered as asynchronous.
  *
  * <p>In terms of target method signatures, any parameter types are supported.
- * However, the return type is constrained to either <code>void</code> or
- * <code>java.util.concurrent.Future</code>. In the latter case, the Future handle
- * returned from the proxy will be an actual asynchronous Future that can be used
+ * However, the return type is constrained to either {@code void} or
+ * {@link java.util.concurrent.Future}. In the latter case, the {@code Future} handle
+ * returned from the proxy will be an actual asynchronous {@code Future} that can be used
  * to track the result of the asynchronous method execution. However, since the
  * target method needs to implement the same signature, it will have to return
- * a temporary Future handle that just passes the return value through: e.g.
- * Spring's {@link AsyncResult} or EJB 3.1's <code>javax.ejb.AsyncResult</code>.
+ * a temporary {@code Future} handle that just passes the return value through: e.g.
+ * Spring's {@link AsyncResult} or EJB 3.1's {@link javax.ejb.AsyncResult}.
  *
  * @author Juergen Hoeller
  * @since 3.0

org.springframework.context/src/main/java/org/springframework/scheduling/annotation/AsyncAnnotationAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -45,11 +45,12 @@ import org.springframework.util.Assert;
  *
  * @author Juergen Hoeller
  * @since 3.0
- * @see PersistenceExceptionTranslationAdvisor
+ * @see org.springframework.dao.annotation.PersistenceExceptionTranslationAdvisor
  * @see org.springframework.stereotype.Repository
  * @see org.springframework.dao.DataAccessException
  * @see org.springframework.dao.support.PersistenceExceptionTranslator
  */
+@SuppressWarnings("serial")
 public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor {
 
 	private Advice advice;
@@ -58,14 +59,14 @@ public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor {
 
 
 	/**
-	 * Create a new ConcurrencyAnnotationBeanPostProcessor for bean-style configuration.
+	 * Create a new {@code AsyncAnnotationAdvisor} for bean-style configuration.
 	 */
 	public AsyncAnnotationAdvisor() {
 		this(new SimpleAsyncTaskExecutor());
 	}
 
 	/**
-	 * Create a new ConcurrencyAnnotationBeanPostProcessor for the given task executor.
+	 * Create a new {@code AsyncAnnotationAdvisor} for the given task executor.
 	 * @param executor the task executor to use for asynchronous methods
 	 */
 	@SuppressWarnings("unchecked")
@@ -74,7 +75,7 @@ public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor {
 		asyncAnnotationTypes.add(Async.class);
 		ClassLoader cl = AsyncAnnotationAdvisor.class.getClassLoader();
 		try {
-			asyncAnnotationTypes.add((Class) cl.loadClass("javax.ejb.Asynchronous"));
+			asyncAnnotationTypes.add((Class<? extends Annotation>) cl.loadClass("javax.ejb.Asynchronous"));
 		}
 		catch (ClassNotFoundException ex) {
 			// If EJB 3.1 API not present, simply ignore.
@@ -126,8 +127,8 @@ public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor {
 	}
 
 	/**
-	 * Calculate a pointcut for the given target class, if any.
-	 * @param targetClass the class to introspect
+	 * Calculate a pointcut for the given async annotation types, if any.
+	 * @param asyncAnnotationTypes the async annotation types to introspect
 	 * @return the applicable Pointcut object, or <code>null</code> if none
 	 */
 	protected Pointcut buildPointcut(Set<Class<? extends Annotation>> asyncAnnotationTypes) {

org.springframework.context/src/main/resources/org/springframework/scheduling/config/spring-task-3.1.xsd

@@ -35,7 +35,7 @@
 					<xsd:documentation><![CDATA[
 	Specifies the java.util.Executor instance to use when invoking asynchronous methods.
 	If not provided, an instance of org.springframework.core.task.SimpleAsyncTaskExecutor
-	will be used by default
+	will be used by default.
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>

org.springframework.context/src/test/java/org/springframework/scheduling/annotation/AsyncExecutionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -18,8 +18,6 @@ package org.springframework.scheduling.annotation;
 
 import java.util.concurrent.Future;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 import org.junit.Test;
 
 import org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator;
@@ -27,7 +25,8 @@ import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.support.GenericApplicationContext;
-import org.springframework.scheduling.annotation.AsyncResult;
+
+import static org.junit.Assert.*;
 
 /**
  * @author Juergen Hoeller
@@ -155,7 +154,6 @@ public class AsyncExecutionTests {
 
 		@Async
 		public void doSomething(int i) {
-			System.out.println(Thread.currentThread().getName() + ": " + i);
 			assertTrue(!Thread.currentThread().getName().equals(originalThreadName));
 		}
 
@@ -171,7 +169,6 @@ public class AsyncExecutionTests {
 	public static class AsyncClassBean {
 
 		public void doSomething(int i) {
-			System.out.println(Thread.currentThread().getName() + ": " + i);
 			assertTrue(!Thread.currentThread().getName().equals(originalThreadName));
 		}
 
@@ -194,7 +191,6 @@ public class AsyncExecutionTests {
 	public static class AsyncInterfaceBean implements AsyncInterface {
 
 		public void doSomething(int i) {
-			System.out.println(Thread.currentThread().getName() + ": " + i);
 			assertTrue(!Thread.currentThread().getName().equals(originalThreadName));
 		}
 
@@ -224,7 +220,6 @@ public class AsyncExecutionTests {
 		}
 
 		public void doSomething(int i) {
-			System.out.println(Thread.currentThread().getName() + ": " + i);
 			assertTrue(!Thread.currentThread().getName().equals(originalThreadName));
 		}
 
@@ -235,7 +230,7 @@ public class AsyncExecutionTests {
 	}
 
 
-	public static class AsyncMethodListener implements ApplicationListener {
+	public static class AsyncMethodListener implements ApplicationListener<ApplicationEvent> {
 
 		@Async
 		public void onApplicationEvent(ApplicationEvent event) {
@@ -246,7 +241,7 @@ public class AsyncExecutionTests {
 
 
 	@Async
-	public static class AsyncClassListener implements ApplicationListener {
+	public static class AsyncClassListener implements ApplicationListener<ApplicationEvent> {
 
 		public AsyncClassListener() {
 			listenerConstructed++;

org.springframework.context/src/test/java/org/springframework/scheduling/annotation/EnableAsyncTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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 +16,15 @@
 
 package org.springframework.scheduling.annotation;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.Matchers.startsWith;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
-
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
+
 import java.util.concurrent.Executor;
 
 import org.junit.Test;
+
 import org.springframework.aop.Advisor;
 import org.springframework.aop.framework.Advised;
 import org.springframework.aop.support.AopUtils;
@@ -39,6 +36,11 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.Matchers.startsWith;
+
+import static org.junit.Assert.*;
+
 /**
  * Tests use of @EnableAsync on @Configuration classes.
  *