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ActiveMQ example source code file (CamelMessageConsumer.java)

This example ActiveMQ source code file (CamelMessageConsumer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - ActiveMQ tags/keywords

activemqsession, camelmessageconsumer, consumer, endpoint, exception, exception, exchange, jmsexception, jmsexception, message, message, messagelistener, string, string

The ActiveMQ CamelMessageConsumer.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.activemq.camel;

import javax.jms.IllegalStateException;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;

import org.apache.activemq.ActiveMQSession;
import org.apache.activemq.util.JMSExceptionSupport;
import org.apache.camel.Consumer;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.PollingConsumer;
import org.apache.camel.Processor;

/**
 * A JMS {@link javax.jms.MessageConsumer} which consumes message exchanges from
 * a Camel {@link Endpoint}
 * 
 * 
 */
public class CamelMessageConsumer implements MessageConsumer {
    private final CamelDestination destination;
    private final Endpoint endpoint;
    private final ActiveMQSession session;
    private final String messageSelector;
    private final boolean noLocal;
    private MessageListener messageListener;
    private Consumer consumer;
    private PollingConsumer pollingConsumer;
    private boolean closed;

    public CamelMessageConsumer(CamelDestination destination, Endpoint endpoint, ActiveMQSession session, String messageSelector, boolean noLocal) {
        this.destination = destination;
        this.endpoint = endpoint;
        this.session = session;
        this.messageSelector = messageSelector;
        this.noLocal = noLocal;
    }

    public void close() throws JMSException {
        if (!closed) {
            closed = true;
            try {
                if (consumer != null) {
                    consumer.stop();
                }
                if (pollingConsumer != null) {
                    pollingConsumer.stop();
                }
            } catch (JMSException e) {
                throw e;
            } catch (Exception e) {
                throw JMSExceptionSupport.create(e);
            }
        }
    }

    public MessageListener getMessageListener() throws JMSException {
        return messageListener;
    }

    public void setMessageListener(MessageListener messageListener) throws JMSException {
        this.messageListener = messageListener;
        if (messageListener != null && consumer == null) {
            consumer = createConsumer();
        }
    }

    public Message receive() throws JMSException {
        Exchange exchange = getPollingConsumer().receive();
        return createMessage(exchange);
    }

    public Message receive(long timeoutMillis) throws JMSException {
        Exchange exchange = getPollingConsumer().receive(timeoutMillis);
        return createMessage(exchange);
    }

    public Message receiveNoWait() throws JMSException {
        Exchange exchange = getPollingConsumer().receiveNoWait();
        return createMessage(exchange);
    }

    // Properties
    // -----------------------------------------------------------------------

    public CamelDestination getDestination() {
        return destination;
    }

    public Endpoint getEndpoint() {
        return endpoint;
    }

    public String getMessageSelector() {
        return messageSelector;
    }

    public boolean isNoLocal() {
        return noLocal;
    }

    public ActiveMQSession getSession() {
        return session;
    }

    // Implementation methods
    // -----------------------------------------------------------------------

    protected PollingConsumer getPollingConsumer() throws JMSException {
        try {
            if (pollingConsumer == null) {
                pollingConsumer = endpoint.createPollingConsumer();
                pollingConsumer.start();
            }
            return pollingConsumer;
        } catch (JMSException e) {
            throw e;
        } catch (Exception e) {
            throw JMSExceptionSupport.create(e);
        }
    }

    protected Message createMessage(Exchange exchange) throws JMSException {
        if (exchange != null) {
            Message message = destination.getBinding().makeJmsMessage(exchange, session);
            return message;
        } else {
            return null;
        }
    }

    protected Consumer createConsumer() throws JMSException {
        try {
            Consumer answer = endpoint.createConsumer(new Processor() {
                public void process(Exchange exchange) throws Exception {
                    Message message = createMessage(exchange);
                    getMessageListener().onMessage(message);
                }
            });
            answer.start();
            return answer;
        } catch (JMSException e) {
            throw e;
        } catch (Exception e) {
            throw JMSExceptionSupport.create(e);
        }
    }

    protected void checkClosed() throws javax.jms.IllegalStateException {
        if (closed) {
            throw new IllegalStateException("The producer is closed");
        }
    }
}

Other ActiveMQ examples (source code examples)

Here is a short list of links related to this ActiveMQ CamelMessageConsumer.java source code file:

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