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ActiveMQ example source code file (ActiveMQOutputStream.java)

This example ActiveMQ source code file (ActiveMQOutputStream.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

activemqbytesmessage, activemqoutputstream, amq_stream_chunk_size, integer, io, ioexception, ioexception, jmsexception, jmsexception, map, object, object, producerinfo, string, string, util

The ActiveMQ ActiveMQOutputStream.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 java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.jms.InvalidDestinationException;
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.MessageId;
import org.apache.activemq.command.ProducerId;
import org.apache.activemq.command.ProducerInfo;
import org.apache.activemq.util.IOExceptionSupport;

/**
 * 
 */
public class ActiveMQOutputStream extends OutputStream implements Disposable {

    protected int count;

    final byte buffer[];

    private final ActiveMQConnection connection;
    private final Map<String, Object> properties;
    private final ProducerInfo info;

    private long messageSequence;
    private boolean closed;
    private final int deliveryMode;
    private final int priority;
    private final long timeToLive;

    /**
     * JMS Property which is used to specify the size (in kb) which is used as chunk size when splitting the stream. Default is 64kb
     */
    public final static String AMQ_STREAM_CHUNK_SIZE = "AMQ_STREAM_CHUNK_SIZE";

    public ActiveMQOutputStream(ActiveMQConnection connection, ProducerId producerId, ActiveMQDestination destination, Map<String, Object> properties, int deliveryMode, int priority,
                                long timeToLive) throws JMSException {
        this.connection = connection;
        this.deliveryMode = deliveryMode;
        this.priority = priority;
        this.timeToLive = timeToLive;
        this.properties = properties == null ? null : new HashMap<String, Object>(properties);

        Integer chunkSize = this.properties == null ? null : (Integer) this.properties.get(AMQ_STREAM_CHUNK_SIZE);
        if (chunkSize == null) {
            chunkSize = 64 * 1024;
        } else {
            if (chunkSize < 1) {
                throw new IllegalArgumentException("Chunk size must be greater then 0");
            } else {
                chunkSize *= 1024;
            }
        }

        buffer = new byte[chunkSize];

        if (destination == null) {
            throw new InvalidDestinationException("Don't understand null destinations");
        }

        this.info = new ProducerInfo(producerId);
        this.info.setDestination(destination);

        this.connection.addOutputStream(this);
        this.connection.asyncSendPacket(info);
    }

    public void close() throws IOException {
        if (!closed) {
            flushBuffer();
            try {
                // Send an EOS style empty message to signal EOS.
                send(new ActiveMQMessage(), true);
                dispose();
                this.connection.asyncSendPacket(info.createRemoveCommand());
            } catch (JMSException e) {
                IOExceptionSupport.create(e);
            }
        }
    }

    public void dispose() {
        if (!closed) {
            this.connection.removeOutputStream(this);
            closed = true;
        }
    }

    public synchronized void write(int b) throws IOException {
        buffer[count++] = (byte) b;
        if (count == buffer.length) {
            flushBuffer();
        }
    }

    public synchronized void write(byte b[], int off, int len) throws IOException {
        while (len > 0) {
            int max = Math.min(len, buffer.length - count);
            System.arraycopy(b, off, buffer, count, max);

            len -= max;
            count += max;
            off += max;

            if (count == buffer.length) {
                flushBuffer();
            }
        }
    }

    public synchronized void flush() throws IOException {
        flushBuffer();
    }

    private void flushBuffer() throws IOException {
        if (count != 0) {
            try {
                ActiveMQBytesMessage msg = new ActiveMQBytesMessage();
                msg.writeBytes(buffer, 0, count);
                send(msg, false);
            } catch (JMSException e) {
                throw IOExceptionSupport.create(e);
            }
            count = 0;
        }
    }

    /**
     * @param msg
     * @throws JMSException
     */
    private void send(ActiveMQMessage msg, boolean eosMessage) throws JMSException {
        if (properties != null) {
            for (Iterator iter = properties.keySet().iterator(); iter.hasNext();) {
                String key = (String) iter.next();
                Object value = properties.get(key);
                msg.setObjectProperty(key, value);
            }
        }
        msg.setType("org.apache.activemq.Stream");
        msg.setGroupID(info.getProducerId().toString());
        if (eosMessage) {
            msg.setGroupSequence(-1);
        } else {
            msg.setGroupSequence((int) messageSequence);
        }
        MessageId id = new MessageId(info.getProducerId(), messageSequence++);
        connection.send(info.getDestination(), msg, id, deliveryMode, priority, timeToLive, !eosMessage);
    }

    public String toString() {
        return "ActiveMQOutputStream { producerId=" + info.getProducerId() + " }";
    }

}

Other ActiveMQ examples (source code examples)

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