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ActiveMQ example source code file (StompSubscription.java)

This example ActiveMQ source code file (StompSubscription.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, auto_ack, client_ack, consumerinfo, individual_ack, io, messageack, messageack, messagedispatch, messagedispatch, messageid, messageid, stompsubscription, string, string, util

The ActiveMQ StompSubscription.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.transport.stomp;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Map.Entry;

import javax.jms.JMSException;

import org.apache.activemq.command.ActiveMQBytesMessage;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQMessage;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageDispatch;
import org.apache.activemq.command.MessageId;
import org.apache.activemq.command.TransactionId;

/**
 * Keeps track of the STOMP subscription so that acking is correctly done.
 *
 * @author <a href="http://hiramchirino.com">chirino
 */
public class StompSubscription {

    public static final String AUTO_ACK = Stomp.Headers.Subscribe.AckModeValues.AUTO;
    public static final String CLIENT_ACK = Stomp.Headers.Subscribe.AckModeValues.CLIENT;
    public static final String INDIVIDUAL_ACK = Stomp.Headers.Subscribe.AckModeValues.INDIVIDUAL;

    private final ProtocolConverter protocolConverter;
    private final String subscriptionId;
    private final ConsumerInfo consumerInfo;

    private final LinkedHashMap<MessageId, MessageDispatch> dispatchedMessage = new LinkedHashMap();
    private final LinkedList<MessageDispatch> unconsumedMessage = new LinkedList();

    private String ackMode = AUTO_ACK;
    private ActiveMQDestination destination;
    private String transformation;


    public StompSubscription(ProtocolConverter stompTransport, String subscriptionId, ConsumerInfo consumerInfo, String transformation) {
        this.protocolConverter = stompTransport;
        this.subscriptionId = subscriptionId;
        this.consumerInfo = consumerInfo;
        this.transformation = transformation;
    }

    void onMessageDispatch(MessageDispatch md) throws IOException, JMSException {
        ActiveMQMessage message = (ActiveMQMessage)md.getMessage();
        if (ackMode == CLIENT_ACK) {
            synchronized (this) {
                dispatchedMessage.put(message.getMessageId(), md);
            }
        } else if (ackMode == INDIVIDUAL_ACK) {
            synchronized (this) {
                dispatchedMessage.put(message.getMessageId(), md);
            }
        } else if (ackMode == AUTO_ACK) {
            MessageAck ack = new MessageAck(md, MessageAck.STANDARD_ACK_TYPE, 1);
            protocolConverter.getStompTransport().sendToActiveMQ(ack);
        }

        boolean ignoreTransformation = false;

        if (transformation != null && !( message instanceof ActiveMQBytesMessage ) ) {
       		message.setReadOnlyProperties(false);
        	message.setStringProperty(Stomp.Headers.TRANSFORMATION, transformation);
        } else {
        	if (message.getStringProperty(Stomp.Headers.TRANSFORMATION) != null) {
        		ignoreTransformation = true;
        	}
        }

        StompFrame command = protocolConverter.convertMessage(message, ignoreTransformation);

        command.setAction(Stomp.Responses.MESSAGE);
        if (subscriptionId != null) {
            command.getHeaders().put(Stomp.Headers.Message.SUBSCRIPTION, subscriptionId);
        }

        protocolConverter.getStompTransport().sendToStomp(command);
    }

    synchronized void onStompAbort(TransactionId transactionId) {
    	unconsumedMessage.clear();
    }

    synchronized void onStompCommit(TransactionId transactionId) {
    	for (Iterator iter = dispatchedMessage.entrySet().iterator(); iter.hasNext();) {
            Map.Entry entry = (Entry)iter.next();
            MessageId id = (MessageId)entry.getKey();
            MessageDispatch msg = (MessageDispatch)entry.getValue();
            if (unconsumedMessage.contains(msg)) {
            	iter.remove();
            }
    	}
    	unconsumedMessage.clear();
    }

    synchronized MessageAck onStompMessageAck(String messageId, TransactionId transactionId) {

    	MessageId msgId = new MessageId(messageId);

        if (!dispatchedMessage.containsKey(msgId)) {
            return null;
        }

        MessageAck ack = new MessageAck();
        ack.setDestination(consumerInfo.getDestination());
        ack.setConsumerId(consumerInfo.getConsumerId());

        if (ackMode == CLIENT_ACK) {
        	ack.setAckType(MessageAck.STANDARD_ACK_TYPE);
            int count = 0;
            for (Iterator iter = dispatchedMessage.entrySet().iterator(); iter.hasNext();) {

                Map.Entry entry = (Entry)iter.next();
                MessageId id = (MessageId)entry.getKey();
                MessageDispatch msg = (MessageDispatch)entry.getValue();

                if (ack.getFirstMessageId() == null) {
                    ack.setFirstMessageId(id);
                }

                if (transactionId != null) {
                	if (!unconsumedMessage.contains(msg)) {
                		unconsumedMessage.add(msg);
                	}
                } else {
                	iter.remove();
                }


                count++;

                if (id.equals(msgId)) {
                    ack.setLastMessageId(id);
                    break;
                }

            }
            ack.setMessageCount(count);
            if (transactionId != null) {
            	ack.setTransactionId(transactionId);
            }
        }
        else if (ackMode == INDIVIDUAL_ACK) {
            ack.setAckType(MessageAck.INDIVIDUAL_ACK_TYPE);
            ack.setMessageID(msgId);
            if (transactionId != null) {
            	unconsumedMessage.add(dispatchedMessage.get(msgId));
            	ack.setTransactionId(transactionId);
            }
            dispatchedMessage.remove(msgId);
        }
        return ack;
    }

    public String getAckMode() {
        return ackMode;
    }

    public void setAckMode(String ackMode) {
        this.ackMode = ackMode;
    }

    public String getSubscriptionId() {
        return subscriptionId;
    }

    public void setDestination(ActiveMQDestination destination) {
        this.destination = destination;
    }

    public ActiveMQDestination getDestination() {
        return destination;
    }

    public ConsumerInfo getConsumerInfo() {
        return consumerInfo;
    }

}

Other ActiveMQ examples (source code examples)

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

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