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ActiveMQ example source code file (MessageListenerDeadLetterTest.java)

This example ActiveMQ source code file (MessageListenerDeadLetterTest.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

activemqconnection, activemqconnectionfactory, activemqqueue, atomicinteger, atomicinteger, error, error, exception, exception, override, redeliverypolicy, rollbackmessagelistener, rollbackmessagelistener, will

The ActiveMQ MessageListenerDeadLetterTest.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.broker.policy;

import java.util.concurrent.atomic.AtomicInteger;

import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.Session;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.RedeliveryPolicy;
import org.apache.activemq.command.ActiveMQQueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MessageListenerDeadLetterTest extends DeadLetterTestSupport {
    private static final Logger LOG = LoggerFactory
            .getLogger(MessageListenerDeadLetterTest.class);

    private int rollbackCount;

    private Session dlqSession;

    private final Error[] error = new Error[1];

    protected void doTest() throws Exception {
        messageCount = 200;
        connection.start();

        ActiveMQConnection amqConnection = (ActiveMQConnection) connection;
        rollbackCount = amqConnection.getRedeliveryPolicy().getMaximumRedeliveries() + 1;
        LOG.info("Will redeliver messages: " + rollbackCount + " times");

        makeConsumer();
        makeDlqConsumer();

        sendMessages();

        // now lets receive and rollback N times
        int maxRollbacks = messageCount * rollbackCount;
        consumer.setMessageListener(new RollbackMessageListener(maxRollbacks, rollbackCount));

        for (int i = 0; i < messageCount; i++) {
            Message msg = dlqConsumer.receive(4000);
            if (error[0] != null) {
                // error from message listener
                throw error[0];
            }
            assertMessage(msg, i);
            assertNotNull("Should be a DLQ message for loop: " + i, msg);
        }
        if (error[0] != null) {
            throw error[0];
        }
    }

    protected void makeDlqConsumer() throws JMSException {
        dlqDestination = createDlqDestination();

        LOG.info("Consuming from dead letter on: " + dlqDestination);
        dlqConsumer = dlqSession.createConsumer(dlqDestination);
    }

    @Override
    protected void setUp() throws Exception {
        transactedMode = true;
        super.setUp();
        dlqSession = connection.createSession(transactedMode, acknowledgeMode);
    }

    @Override
    protected void tearDown() throws Exception {
        dlqConsumer.close();
        dlqSession.close();
        session.close();
        super.tearDown();
    };

    protected ActiveMQConnectionFactory createConnectionFactory()
            throws Exception {
        ActiveMQConnectionFactory answer = super.createConnectionFactory();
        RedeliveryPolicy policy = new RedeliveryPolicy();
        policy.setMaximumRedeliveries(3);
        policy.setBackOffMultiplier((short) 1);
        policy.setRedeliveryDelay(0);
        policy.setInitialRedeliveryDelay(0);
        policy.setUseExponentialBackOff(false);
        answer.setRedeliveryPolicy(policy);
        return answer;
    }

    protected Destination createDlqDestination() {
        return new ActiveMQQueue("ActiveMQ.DLQ");
    }

    class RollbackMessageListener implements MessageListener {

        final int maxRollbacks;

        final int deliveryCount;

        AtomicInteger rollbacks = new AtomicInteger();

        RollbackMessageListener(int c, int delvery) {
            maxRollbacks = c;
            deliveryCount = delvery;
        }

        public void onMessage(Message message) {
            try {
                int expectedMessageId = rollbacks.get() / deliveryCount;
                LOG.info("expecting messageId: " + expectedMessageId);
                assertMessage(message, expectedMessageId);
                if (rollbacks.incrementAndGet() > maxRollbacks) {
                    fail("received too many messages, already done too many rollbacks: "
                            + rollbacks);
                }
                session.rollback();

            } catch (Throwable e) {
                LOG.error("unexpected exception:" + e, e);
                // propagating assertError to execution task will cause a hang
                // at shutdown
                if (e instanceof Error) {
                    error[0] = (Error) e;
                } else {
                    fail("unexpected exception: " + e);
                }

            }
        }
    }
}

Other ActiveMQ examples (source code examples)

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

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