ActiveMQ example source code file (AdvisoryConsumer.java)

This example ActiveMQ source code file (AdvisoryConsumer.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

activemqdestination, activemqtempdestination, activemqtempdestination, advisoryconsumer, advisoryconsumer, consumerid, consumerinfo, datastructure, failed, jmsexception, jmsexception, logger, messageack, messageack

The ActiveMQ AdvisoryConsumer.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;

import javax.jms.JMSException;

import org.apache.activemq.advisory.AdvisorySupport;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQTempDestination;
import org.apache.activemq.command.ConsumerId;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.DataStructure;
import org.apache.activemq.command.DestinationInfo;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageDispatch;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class AdvisoryConsumer implements ActiveMQDispatcher {
    private static final transient Logger LOG = LoggerFactory.getLogger(AdvisoryConsumer.class);

    int deliveredCounter;

    private final ActiveMQConnection connection;
    private ConsumerInfo info;
    private boolean closed;

    public AdvisoryConsumer(ActiveMQConnection connection, ConsumerId consumerId) throws JMSException {
        this.connection = connection;
        info = new ConsumerInfo(consumerId);
        info.setDestination(AdvisorySupport.TEMP_DESTINATION_COMPOSITE_ADVISORY_TOPIC);
        info.setPrefetchSize(1000);
        info.setNoLocal(true);

        this.connection.addDispatcher(info.getConsumerId(), this);
        this.connection.syncSendPacket(this.info);
    }

    public synchronized void dispose() {
        if (!closed) {
            try {
                this.connection.asyncSendPacket(info.createRemoveCommand());
            } catch (JMSException e) {
                LOG.debug("Failed to send remove command: " + e, e);
            }
            this.connection.removeDispatcher(info.getConsumerId());
            closed = true;
        }
    }

    public void dispatch(MessageDispatch md) {

        // Auto ack messages when we reach 75% of the prefetch
        deliveredCounter++;
        if (deliveredCounter > (0.75 * info.getPrefetchSize())) {
            try {
                MessageAck ack = new MessageAck(md, MessageAck.STANDARD_ACK_TYPE, deliveredCounter);
                connection.asyncSendPacket(ack);
                deliveredCounter = 0;
            } catch (JMSException e) {
                connection.onClientInternalException(e);
            }
        }

        DataStructure o = md.getMessage().getDataStructure();
        if (o != null && o.getClass() == DestinationInfo.class) {
            processDestinationInfo((DestinationInfo)o);
        } else {
            //This can happen across networks
            if (LOG.isDebugEnabled()) {
                LOG.debug("Unexpected message was dispatched to the AdvisoryConsumer: "+md);
            }
        }

    }

    private void processDestinationInfo(DestinationInfo dinfo) {
        ActiveMQDestination dest = dinfo.getDestination();
        if (!dest.isTemporary()) {
            return;
        }

        ActiveMQTempDestination tempDest = (ActiveMQTempDestination)dest;
        if (dinfo.getOperationType() == DestinationInfo.ADD_OPERATION_TYPE) {
            connection.activeTempDestinations.put(tempDest, tempDest);
        } else if (dinfo.getOperationType() == DestinationInfo.REMOVE_OPERATION_TYPE) {
            connection.activeTempDestinations.remove(tempDest);
        }
    }

}