001/*
002 * Copyright 2002-2013 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.messaging.core;
018
019import org.springframework.beans.BeansException;
020import org.springframework.beans.factory.BeanFactory;
021import org.springframework.beans.factory.BeanFactoryAware;
022import org.springframework.messaging.MessageChannel;
023import org.springframework.util.Assert;
024
025/**
026 * An implementation of {@link DestinationResolver} that interprets a destination
027 * name as the bean name of a {@link MessageChannel} and looks up the bean in
028 * the configured {@link BeanFactory}.
029 *
030 * @author Mark Fisher
031 * @since 4.0
032 */
033public class BeanFactoryMessageChannelDestinationResolver
034                implements DestinationResolver<MessageChannel>, BeanFactoryAware {
035
036        private BeanFactory beanFactory;
037
038
039        /**
040         * A default constructor that can be used when the resolver itself is configured
041         * as a Spring bean and will have the {@code BeanFactory} injected as a result
042         * of ing having implemented {@link BeanFactoryAware}.
043         */
044        public BeanFactoryMessageChannelDestinationResolver() {
045        }
046
047        /**
048         * A constructor that accepts a {@link BeanFactory} useful if instantiating this
049         * resolver manually rather than having it defined as a Spring-managed bean.
050         * @param beanFactory the bean factory to perform lookups against
051         */
052        public BeanFactoryMessageChannelDestinationResolver(BeanFactory beanFactory) {
053                Assert.notNull(beanFactory, "beanFactory must not be null");
054                this.beanFactory = beanFactory;
055        }
056
057
058        @Override
059        public void setBeanFactory(BeanFactory beanFactory) {
060                this.beanFactory = beanFactory;
061        }
062
063
064        @Override
065        public MessageChannel resolveDestination(String name) {
066                Assert.state(this.beanFactory != null, "No BeanFactory configured");
067                try {
068                        return this.beanFactory.getBean(name, MessageChannel.class);
069                }
070                catch (BeansException ex) {
071                        throw new DestinationResolutionException(
072                                        "Failed to find MessageChannel bean with name '" + name + "'", ex);
073                }
074        }
075
076}