/*
* Copyright 2009 Red Hat, Inc.
* Red Hat 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.hornetq.jms.example;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.jms.BytesMessage;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.naming.InitialContext;
import org.hornetq.common.example.HornetQExample;
/**
* This example demonstrates the ability of HornetQ to send and consume a very large message, much
* bigger than can fit in RAM.
*
* @author <a href="tim.fox@jboss.com">Tim Fox</a>
* @author <a href="clebert.suconic@jboss.com">Clebert Suconic</a>
*/
public class LargeMessageExample extends HornetQExample
{
public static void main(final String[] args)
{
new LargeMessageExample().run(args);
}
// The message we will send is size 10GiB, even though we are only running in 50MB of RAM on both client and server.
// This may take some considerable time to create, send and consume - if it takes too long or you don't have
// enough disk space just reduce the file size here
// private final long FILE_SIZE = 256L * 1024 * 1024;
private final long FILE_SIZE = 10L * 1024 * 1024 * 1024; // 10 GiB message
@Override
public boolean runExample() throws Exception
{
Connection connection = null;
InitialContext initialContext = null;
try
{
// Step 1. Create an initial context to perform the JNDI lookup.
initialContext = getContext(0);
// Step 2. Perfom a lookup on the queue
Queue queue = (Queue)initialContext.lookup("/queue/exampleQueue");
// Step 3. Perform a lookup on the Connection Factory. This ConnectionFactory has a special attribute set on
// it.
// Messages with more than 10K are considered large
ConnectionFactory cf = (ConnectionFactory)initialContext.lookup("/ConnectionFactory");
// Step 4. Create the JMS objects
connection = cf.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageProducer producer = session.createProducer(queue);
// Step 5. Create a huge file - this will form the body of the message we will send.
System.out.println("Creating a file to send of size " + FILE_SIZE +
" bytes. This may take a little while... " +
"If this is too big for your disk you can easily change the FILE_SIZE in the example.");
File fileInput = new File("huge_message_to_send.dat");
createFile(fileInput, FILE_SIZE);
System.out.println("File created.");
// Step 6. Create a BytesMessage
BytesMessage message = session.createBytesMessage();
// Step 7. We set the InputStream on the message. When sending the message will read the InputStream
// until it gets EOF. In this case we point the InputStream at a file on disk, and it will suck up the entire
// file, however we could use any InputStream not just a FileInputStream.
FileInputStream fileInputStream = new FileInputStream(fileInput);
BufferedInputStream bufferedInput = new BufferedInputStream(fileInputStream);
message.setObjectProperty("JMS_HQ_InputStream", bufferedInput);
System.out.println("Sending the huge message.");
// Step 9. Send the Message
producer.send(message);
System.out.println("Large Message sent");
System.out.println("Stopping server.");
// Step 10. To demonstrate that that we're not simply streaming the message from sending to consumer, we stop
// the server and restart it before consuming the message. This demonstrates that the large message gets
// persisted, like a
// normal persistent message, on the server. If you look at ./build/data/largeMessages you will see the
// largeMessage stored on disk the server
connection.close();
initialContext.close();
stopServer(0);
// Give the server a little time to shutdown properly
Thread.sleep(5000);
startServer(0);
System.out.println("Server restarted.");
// Step 11. Now the server is restarted we can recreate the JMS Objects, and start the new connection
initialContext = getContext(0);
queue = (Queue)initialContext.lookup("/queue/exampleQueue");
cf = (ConnectionFactory)initialContext.lookup("/ConnectionFactory");
connection = cf.createConnection();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageConsumer messageConsumer = session.createConsumer(queue);
connection.start();
System.out.println("Receiving message.");
// Step 12. Receive the message. When we receive the large message we initially just receive the message with
// an empty body.
BytesMessage messageReceived = (BytesMessage)messageConsumer.receive(120000);
System.out.println("Received message with: " + messageReceived.getBodyLength() +
" bytes. Now streaming to file on disk.");
// Step 13. We set an OutputStream on the message. This causes the message body to be written to the
// OutputStream until there are no more bytes to be written.
// You don't have to use a FileOutputStream, you can use any OutputStream.
// You may choose to use the regular BytesMessage or
// StreamMessage interface but this method is much faster for large messages.
File outputFile = new File("huge_message_received.dat");
FileOutputStream fileOutputStream = new FileOutputStream(outputFile);
BufferedOutputStream bufferedOutput = new BufferedOutputStream(fileOutputStream);
// Step 14. This will save the stream and wait until the entire message is written before continuing.
messageReceived.setObjectProperty("JMS_HQ_SaveStream", bufferedOutput);
fileOutputStream.close();
System.out.println("File streamed to disk. Size of received file on disk is " + outputFile.length());
return true;
}
finally
{
// Step 12. Be sure to close our resources!
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}
}
/**
* @param file
* @param fileSize
* @throws FileNotFoundException
* @throws IOException
*/
private void createFile(final File file, final long fileSize) throws FileNotFoundException, IOException
{
FileOutputStream fileOut = new FileOutputStream(file);
BufferedOutputStream buffOut = new BufferedOutputStream(fileOut);
byte[] outBuffer = new byte[1024 * 1024];
for (long i = 0; i < fileSize; i += outBuffer.length)
{
buffOut.write(outBuffer);
}
buffOut.close();
}
}