001/*
002 * Copyright 2002-2015 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.scheduling.annotation;
018
019import java.util.Collection;
020import java.util.concurrent.Executor;
021
022import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
023import org.springframework.beans.factory.annotation.Autowired;
024import org.springframework.context.annotation.Configuration;
025import org.springframework.context.annotation.ImportAware;
026import org.springframework.core.annotation.AnnotationAttributes;
027import org.springframework.core.type.AnnotationMetadata;
028import org.springframework.util.CollectionUtils;
029
030/**
031 * Abstract base {@code Configuration} class providing common structure for enabling
032 * Spring's asynchronous method execution capability.
033 *
034 * @author Chris Beams
035 * @author Stephane Nicoll
036 * @since 3.1
037 * @see EnableAsync
038 */
039@Configuration
040public abstract class AbstractAsyncConfiguration implements ImportAware {
041
042        protected AnnotationAttributes enableAsync;
043
044        protected Executor executor;
045
046        protected AsyncUncaughtExceptionHandler exceptionHandler;
047
048
049        @Override
050        public void setImportMetadata(AnnotationMetadata importMetadata) {
051                this.enableAsync = AnnotationAttributes.fromMap(
052                                importMetadata.getAnnotationAttributes(EnableAsync.class.getName(), false));
053                if (this.enableAsync == null) {
054                        throw new IllegalArgumentException(
055                                        "@EnableAsync is not present on importing class " + importMetadata.getClassName());
056                }
057        }
058
059        /**
060         * Collect any {@link AsyncConfigurer} beans through autowiring.
061         */
062        @Autowired(required = false)
063        void setConfigurers(Collection<AsyncConfigurer> configurers) {
064                if (CollectionUtils.isEmpty(configurers)) {
065                        return;
066                }
067                if (configurers.size() > 1) {
068                        throw new IllegalStateException("Only one AsyncConfigurer may exist");
069                }
070                AsyncConfigurer configurer = configurers.iterator().next();
071                this.executor = configurer.getAsyncExecutor();
072                this.exceptionHandler = configurer.getAsyncUncaughtExceptionHandler();
073        }
074
075}