https://github.com/spring-projects/spring-framework: Spring Context (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 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 java.util.function.Supplier;

import org.aopalliance.aop.Advice;

import org.springframework.aop.Pointcut;
import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.aop.support.AbstractPointcutAdvisor;
import org.springframework.aop.support.ComposablePointcut;
import org.springframework.aop.support.annotation.AnnotationMatchingPointcut;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.function.SingletonSupplier;


Advisor that activates asynchronous method execution through the Async annotation. This annotation can be used at the method and type level in implementation classes as well as in service interfaces. 
This advisor detects the EJB 3.1 javax.ejb.Asynchronous annotation as well, treating it exactly like Spring's own Async. Furthermore, a custom async annotation type may get specified through the "asyncAnnotationType" property. 
Author:Juergen Hoeller
See Also:
Since:3.0
/**
 * 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}
 * annotation as well, treating it exactly like Spring's own {@code Async}.
 * Furthermore, a custom async annotation type may get specified through the
 * {@link #setAsyncAnnotationType "asyncAnnotationType"} property.
 *
 * @author Juergen Hoeller
 * @since 3.0
 * @see Async
 * @see AnnotationAsyncExecutionInterceptor
 */
@SuppressWarnings("serial")
public class AsyncAnnotationAdvisor extends AbstractPointcutAdvisor implements BeanFactoryAware {

	private Advice advice;

	private Pointcut pointcut;


	
Create a new AsyncAnnotationAdvisor for bean-style configuration. 
/**
	 * Create a new {@code AsyncAnnotationAdvisor} for bean-style configuration.
	 */
	public AsyncAnnotationAdvisor() {
		this((Supplier<Executor>) null, (Supplier<AsyncUncaughtExceptionHandler>) null);
	}

	
Create a new AsyncAnnotationAdvisor for the given task executor. 
Params:
  • executor – the task executor to use for asynchronous methods (can be null to trigger default executor resolution)
  • exceptionHandler – the AsyncUncaughtExceptionHandler to use to handle unexpected exception thrown by asynchronous method executions
See Also:
/**
	 * Create a new {@code AsyncAnnotationAdvisor} for the given task executor.
	 * @param executor the task executor to use for asynchronous methods
	 * (can be {@code null} to trigger default executor resolution)
	 * @param exceptionHandler the {@link AsyncUncaughtExceptionHandler} to use to
	 * handle unexpected exception thrown by asynchronous method executions
	 * @see AnnotationAsyncExecutionInterceptor#getDefaultExecutor(BeanFactory)
	 */
	@SuppressWarnings("unchecked")
	public AsyncAnnotationAdvisor(
			@Nullable Executor executor, @Nullable AsyncUncaughtExceptionHandler exceptionHandler) {

		this(SingletonSupplier.ofNullable(executor), SingletonSupplier.ofNullable(exceptionHandler));
	}

	
Create a new AsyncAnnotationAdvisor for the given task executor. 
Params:
  • executor – the task executor to use for asynchronous methods (can be null to trigger default executor resolution)
  • exceptionHandler – the AsyncUncaughtExceptionHandler to use to handle unexpected exception thrown by asynchronous method executions
See Also:
Since:5.1
/**
	 * Create a new {@code AsyncAnnotationAdvisor} for the given task executor.
	 * @param executor the task executor to use for asynchronous methods
	 * (can be {@code null} to trigger default executor resolution)
	 * @param exceptionHandler the {@link AsyncUncaughtExceptionHandler} to use to
	 * handle unexpected exception thrown by asynchronous method executions
	 * @since 5.1
	 * @see AnnotationAsyncExecutionInterceptor#getDefaultExecutor(BeanFactory)
	 */
	@SuppressWarnings("unchecked")
	public AsyncAnnotationAdvisor(
			@Nullable Supplier<Executor> executor, @Nullable Supplier<AsyncUncaughtExceptionHandler> exceptionHandler) {

		Set<Class<? extends Annotation>> asyncAnnotationTypes = new LinkedHashSet<>(2);
		asyncAnnotationTypes.add(Async.class);
		try {
			asyncAnnotationTypes.add((Class<? extends Annotation>)
					ClassUtils.forName("javax.ejb.Asynchronous", AsyncAnnotationAdvisor.class.getClassLoader()));
		}
		catch (ClassNotFoundException ex) {
			// If EJB 3.1 API not present, simply ignore.
		}
		this.advice = buildAdvice(executor, exceptionHandler);
		this.pointcut = buildPointcut(asyncAnnotationTypes);
	}


	
Set the 'async' annotation type.

The default async annotation type is the Async annotation, as well as the EJB 3.1 javax.ejb.Asynchronous annotation (if present). 
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.

Params:
  • asyncAnnotationType – the desired annotation type
/**
	 * 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} 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<>();
		asyncAnnotationTypes.add(asyncAnnotationType);
		this.pointcut = buildPointcut(asyncAnnotationTypes);
	}

	
Set the BeanFactory to be used when looking up executors by qualifier. 
/**
	 * Set the {@code BeanFactory} to be used when looking up executors by qualifier.
	 */
	@Override
	public void setBeanFactory(BeanFactory beanFactory) {
		if (this.advice instanceof BeanFactoryAware) {
			((BeanFactoryAware) this.advice).setBeanFactory(beanFactory);
		}
	}


	@Override
	public Advice getAdvice() {
		return this.advice;
	}

	@Override
	public Pointcut getPointcut() {
		return this.pointcut;
	}


	protected Advice buildAdvice(
			@Nullable Supplier<Executor> executor, @Nullable Supplier<AsyncUncaughtExceptionHandler> exceptionHandler) {

		AnnotationAsyncExecutionInterceptor interceptor = new AnnotationAsyncExecutionInterceptor(null);
		interceptor.configure(executor, exceptionHandler);
		return interceptor;
	}

	
Calculate a pointcut for the given async annotation types, if any.

Params:
  • asyncAnnotationTypes – the async annotation types to introspect
Returns:the applicable Pointcut object, or null if none
/**
	 * 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} 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, true);
			if (result == null) {
				result = new ComposablePointcut(cpc);
			}
			else {
				result.union(cpc);
			}
			result = result.union(mpc);
		}
		return (result != null ? result : Pointcut.TRUE);
	}

}