/*
* Copyright 2002-2009 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.scheduling.annotation;
import java.lang.annotation.Annotation;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.concurrent.Executor;
import org.aopalliance.aop.Advice;
import org.springframework.aop.Pointcut;
import org.springframework.aop.interceptor.AsyncExecutionInterceptor;
import org.springframework.aop.support.AbstractPointcutAdvisor;
import org.springframework.aop.support.ComposablePointcut;
import org.springframework.aop.support.annotation.AnnotationMatchingPointcut;
import org.springframework.core.task.AsyncTaskExecutor;
import org.springframework.core.task.SimpleAsyncTaskExecutor;
import org.springframework.util.Assert;
/**
* Advisor that activates asynchronous method execution through the {@link Async}
* annotation. This annotation can be used at the method and type level in
* implementation classes as well as in service interfaces.
*
* <p>This advisor detects the EJB 3.1 <code>javax.ejb.Asynchronous</code>
* annotation as well, treating it exactly like Spring's own <code>Async</code>.
* Furthermore, a custom async annotation type may get specified through the
* {@link #setAsyncAnnotationType "asyncAnnotationType"} property.
*
* @author Juergen Hoeller
* @since 3.0
* @see PersistenceExceptionTranslationAdvisor
* @see org.springframework.stereotype.Repository
* @see org.springframework.dao.DataAccessException
* @see org.springframework.dao.support.PersistenceExceptionTranslator
*/
public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor {
private Advice advice;
private Pointcut pointcut;
/**
* Create a new ConcurrencyAnnotationBeanPostProcessor for bean-style configuration.
*/
public AsyncAnnotationAdvisor() {
this(new SimpleAsyncTaskExecutor());
}
/**
* Create a new ConcurrencyAnnotationBeanPostProcessor for the given task executor.
* @param executor the task executor to use for asynchronous methods
*/
@SuppressWarnings("unchecked")
public AsyncAnnotationAdvisor(Executor executor) {
Set<Class<? extends Annotation>> asyncAnnotationTypes = new LinkedHashSet<Class<? extends Annotation>>(2);
asyncAnnotationTypes.add(Async.class);
ClassLoader cl = AsyncAnnotationAdvisor.class.getClassLoader();
try {
asyncAnnotationTypes.add((Class) cl.loadClass("javax.ejb.Asynchronous"));
}
catch (ClassNotFoundException ex) {
// If EJB 3.1 API not present, simply ignore.
}
this.advice = buildAdvice(executor);
this.pointcut = buildPointcut(asyncAnnotationTypes);
}
/**
* Specify the task executor to use for asynchronous methods.
*/
public void setTaskExecutor(Executor executor) {
this.advice = buildAdvice(executor);
}
/**
* Set the 'async' annotation type.
* <p>The default async annotation type is the {@link Async} annotation, as well
* as the EJB 3.1 <code>javax.ejb.Asynchronous</code> annotation (if present).
* <p>This setter property exists so that developers can provide their own
* (non-Spring-specific) annotation type to indicate that a method is to
* be executed asynchronously.
* @param asyncAnnotationType the desired annotation type
*/
public void setAsyncAnnotationType(Class<? extends Annotation> asyncAnnotationType) {
Assert.notNull(asyncAnnotationType, "'asyncAnnotationType' must not be null");
Set<Class<? extends Annotation>> asyncAnnotationTypes = new HashSet<Class<? extends Annotation>>();
asyncAnnotationTypes.add(asyncAnnotationType);
this.pointcut = buildPointcut(asyncAnnotationTypes);
}
public Advice getAdvice() {
return this.advice;
}
public Pointcut getPointcut() {
return this.pointcut;
}
protected Advice buildAdvice(Executor executor) {
if (executor instanceof AsyncTaskExecutor) {
return new AsyncExecutionInterceptor((AsyncTaskExecutor) executor);
}
else {
return new AsyncExecutionInterceptor(executor);
}
}
/**
* Calculate a pointcut for the given target class, if any.
* @param targetClass the class to introspect
* @return the applicable Pointcut object, or <code>null</code> if none
*/
protected Pointcut buildPointcut(Set<Class<? extends Annotation>> asyncAnnotationTypes) {
ComposablePointcut result = null;
for (Class<? extends Annotation> asyncAnnotationType : asyncAnnotationTypes) {
Pointcut cpc = new AnnotationMatchingPointcut(asyncAnnotationType, true);
Pointcut mpc = new AnnotationMatchingPointcut(null, asyncAnnotationType);
if (result == null) {
result = new ComposablePointcut(cpc).union(mpc);
}
else {
result.union(cpc).union(mpc);
}
}
return result;
}
}
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