org.springframework.integration.x.bus.MessageBusAwareChannelResolver.java Source code

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Here is the source code for org.springframework.integration.x.bus.MessageBusAwareChannelResolver.java

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/*
 * Copyright 2013 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.integration.x.bus;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.core.BeanFactoryMessageChannelDestinationResolver;

/**
 * A {@link org.springframework.integration.support.channel.ChannelResolver} implementation that first checks for any
 * channel whose name begins with a colon in the {@link MessageBus}.
 * 
 * @author Mark Fisher
 */
public class MessageBusAwareChannelResolver extends BeanFactoryMessageChannelDestinationResolver {

    private final Log logger = LogFactory.getLog(this.getClass());

    private final Map<String, MessageChannel> channels = new HashMap<String, MessageChannel>();

    private volatile MessageBus messageBus;

    @Override
    public void setBeanFactory(BeanFactory beanFactory) {
        super.setBeanFactory(beanFactory);
        try {
            messageBus = beanFactory.getBean(MessageBus.class);
        } catch (Exception e) {
            logger.warn("failed to locate a MessageBus in the BeanFactory", e);
        }
    }

    @Override
    public MessageChannel resolveDestination(String name) {
        MessageChannel channel = null;
        if (name.indexOf(":") != -1) {
            String channelName = name;
            channel = channels.get(channelName);
            if (channel == null && messageBus != null) {
                channel = new DirectChannel();
                messageBus.bindProducer(channelName, channel, true);
                channels.put(channelName, channel);
            }
        }
        if (channel == null) {
            channel = super.resolveDestination(name);
        }
        return channel;
    }

}