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ActiveMQ example source code file (ConsumerBean.java)

This example ActiveMQ source code file (ConsumerBean.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

arraylist, caught, caught, consumerbean, end, end, interruptedexception, interruptedexception, list, list, logger, messagelistener, received, util, waiting

The ActiveMQ ConsumerBean.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.spring;

import java.util.ArrayList;
import java.util.List;

import javax.jms.Message;
import javax.jms.MessageListener;

import junit.framework.Assert;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ConsumerBean extends Assert implements MessageListener {
    private static final Logger LOG = LoggerFactory.getLogger(ConsumerBean.class);
    private final List<Message> messages = new ArrayList();
    private boolean verbose;

    /**
     * Constructor.
     */
    public ConsumerBean() {
    }

    
    /**
     * @return all the messages on the list so far, clearing the buffer
     */
    public List<Message> flushMessages() {
        List<Message> answer = null;
        synchronized(messages) {
        answer = new ArrayList<Message>(messages);
        messages.clear();
        }
        return answer;
    }

    /**
     * Method implemented from MessageListener interface.
     *
     * @param message
     */
    public void onMessage(Message message) {
        synchronized (messages) {
            messages.add(message);
            if (verbose) {
                LOG.info("Received: " + message);
            }
            messages.notifyAll();
        }
    }

    /**
     * Use to wait for a single message to arrive.
     */
    public void waitForMessageToArrive() {
        LOG.info("Waiting for message to arrive");

        long start = System.currentTimeMillis();

        try {
            if (hasReceivedMessage()) {
                synchronized (messages) {
                    messages.wait(4000);
                }
            }
        } catch (InterruptedException e) {
            LOG.info("Caught: " + e);
        }
        long end = System.currentTimeMillis() - start;

        LOG.info("End of wait for " + end + " millis");
    }

    /**
     * Used to wait for a message to arrive given a particular message count.
     *
     * @param messageCount
     */
    public void waitForMessagesToArrive(int messageCount) {
        long maxRemainingMessageCount = Math.max(0, messageCount - messages.size());
        LOG.info("Waiting for (" + maxRemainingMessageCount + ") message(s) to arrive");
        long start = System.currentTimeMillis();
        long maxWaitTime = start + 120 * 1000;
        while (maxRemainingMessageCount > 0) {
            try {
                synchronized (messages) {
                    messages.wait(1000);
                }
                if (hasReceivedMessages(messageCount) || System.currentTimeMillis() > maxWaitTime) {
                    break;
                }
            } catch (InterruptedException e) {
                LOG.info("Caught: " + e);
            }
            maxRemainingMessageCount = Math.max(0, messageCount - messages.size());
        }
        long end = System.currentTimeMillis() - start;
        LOG.info("End of wait for " + end + " millis");
    }

    public void assertMessagesArrived(int total) {
        waitForMessagesToArrive(total);
        synchronized (messages) {
            int count = messages.size();

            assertEquals("Messages received", total, count);
        }
    }

    public boolean isVerbose() {
        return verbose;
    }

    public void setVerbose(boolean verbose) {
        this.verbose = verbose;
    }

    /**
     * Identifies if the message is empty.
     *
     * @return
     */
    protected boolean hasReceivedMessage() {
        return messages.isEmpty();
    }

    /**
     * Identifies if the message count has reached the total size of message.
     *
     * @param messageCount
     * @return
     */
    protected boolean hasReceivedMessages(int messageCount) {
        synchronized (messages) {
            return messages.size() >= messageCount;
        }
    }
}

Other ActiveMQ examples (source code examples)

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

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