org.springframework.scheduling.annotation.AsyncAnnotationBeanPostProcessor Maven / Gradle / Ivy
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/*
* Copyright 2002-2015 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.concurrent.Executor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.framework.AbstractAdvisingBeanPostProcessor;
import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.core.task.TaskExecutor;
import org.springframework.util.Assert;
/**
* Bean post-processor that automatically applies asynchronous invocation
* behavior to any bean that carries the {@link Async} annotation at class or
* method-level by adding a corresponding {@link AsyncAnnotationAdvisor} to the
* exposed proxy (either an existing AOP proxy or a newly generated proxy that
* implements all of the target's interfaces).
*
* The {@link TaskExecutor} responsible for the asynchronous execution may
* be provided as well as the annotation type that indicates a method should be
* invoked asynchronously. If no annotation type is specified, this post-
* processor will detect both Spring's {@link Async @Async} annotation as well
* as the EJB 3.1 {@code javax.ejb.Asynchronous} annotation.
*
*
For methods having a {@code void} return type, any exception thrown
* during the asynchronous method invocation cannot be accessed by the
* caller. An {@link AsyncUncaughtExceptionHandler} can be specified to handle
* these cases.
*
*
Note: The underlying async advisor applies before existing advisors by default,
* in order to switch to async execution as early as possible in the invocation chain.
*
* @author Mark Fisher
* @author Juergen Hoeller
* @author Stephane Nicoll
* @since 3.0
* @see Async
* @see AsyncAnnotationAdvisor
* @see #setBeforeExistingAdvisors
* @see ScheduledAnnotationBeanPostProcessor
*/
@SuppressWarnings("serial")
public class AsyncAnnotationBeanPostProcessor extends AbstractAdvisingBeanPostProcessor implements BeanFactoryAware {
/**
* The default name of the {@link TaskExecutor} bean to pick up: "taskExecutor".
*
Note that the initial lookup happens by type; this is just the fallback
* in case of multiple executor beans found in the context.
*/
public static final String DEFAULT_TASK_EXECUTOR_BEAN_NAME = "taskExecutor";
protected final Log logger = LogFactory.getLog(getClass());
private Class asyncAnnotationType;
private Executor executor;
private AsyncUncaughtExceptionHandler exceptionHandler;
public AsyncAnnotationBeanPostProcessor() {
setBeforeExistingAdvisors(true);
}
/**
* Set the 'async' annotation type to be detected at either class or method
* level. By default, both the {@link Async} annotation and the EJB 3.1
* {@code javax.ejb.Asynchronous} annotation will be detected.
*
This setter property exists so that developers can provide their own
* (non-Spring-specific) annotation type to indicate that a method (or all
* methods of a given class) should be invoked asynchronously.
* @param asyncAnnotationType the desired annotation type
*/
public void setAsyncAnnotationType(Class asyncAnnotationType) {
Assert.notNull(asyncAnnotationType, "'asyncAnnotationType' must not be null");
this.asyncAnnotationType = asyncAnnotationType;
}
/**
* Set the {@link Executor} to use when invoking methods asynchronously.
*/
public void setExecutor(Executor executor) {
this.executor = executor;
}
/**
* Set the {@link AsyncUncaughtExceptionHandler} to use to handle uncaught
* exceptions thrown by asynchronous method executions.
* @since 4.1
*/
public void setExceptionHandler(AsyncUncaughtExceptionHandler exceptionHandler) {
this.exceptionHandler = exceptionHandler;
}
@Override
public void setBeanFactory(BeanFactory beanFactory) {
Executor executorToUse = this.executor;
if (executorToUse == null) {
try {
// Search for TaskExecutor bean... not plain Executor since that would
// match with ScheduledExecutorService as well, which is unusable for
// our purposes here. TaskExecutor is more clearly designed for it.
executorToUse = beanFactory.getBean(TaskExecutor.class);
}
catch (NoUniqueBeanDefinitionException ex) {
try {
executorToUse = beanFactory.getBean(DEFAULT_TASK_EXECUTOR_BEAN_NAME, TaskExecutor.class);
}
catch (NoSuchBeanDefinitionException ex2) {
throw new IllegalStateException("More than one TaskExecutor bean exists within the context, " +
"and none is named 'taskExecutor'. Mark one of them as primary or name it " +
"'taskExecutor' (possibly as an alias); or specify the AsyncConfigurer interface " +
"and implement getAsyncExecutor() accordingly.", ex);
}
}
catch (NoSuchBeanDefinitionException ex) {
logger.debug("Could not find default TaskExecutor bean", ex);
// Giving up -> falling back to default executor within the advisor...
}
}
AsyncAnnotationAdvisor advisor = new AsyncAnnotationAdvisor(executorToUse, this.exceptionHandler);
if (this.asyncAnnotationType != null) {
advisor.setAsyncAnnotationType(this.asyncAnnotationType);
}
advisor.setBeanFactory(beanFactory);
this.advisor = advisor;
}
}