/*
* 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.artemis.jms.example;
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 java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.activemq.artemis.util.ServerUtil;
/**
* This example demonstrates the ability of ActiveMQ Artemis to send and consume a very large message, much
* bigger than can fit in RAM.
*/
public class LargeMessageExample {
/**
* The message we will send is size 2GiB, even though we are only running in 50MB of RAM on both
* client and server.
* <p>
* 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 static final long FILE_SIZE = 2L;// * 1024 * 1024 * 1024; // 2 GiB message
public static void main(final String[] args) throws Exception {
Process server = null;
Connection connection = null;
InitialContext initialContext = null;
File inputFile = null;
File outputFile = null;
boolean deleteFiles = Boolean.parseBoolean(args[1]);
try {
server = ServerUtil.startServer(args[0], LargeMessageExample.class.getSimpleName(), 0, 5000);
// Step 1. Create an initial context to perform the JNDI lookup.
initialContext = new InitialContext();
// 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.");
inputFile = new File("huge_message_to_send.dat");
createFile(inputFile, 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(inputFile);
BufferedInputStream bufferedInput = new BufferedInputStream(fileInputStream);
message.setObjectProperty("JMS_AMQ_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();
ServerUtil.killServer(server);
server = ServerUtil.startServer(args[0], "LargeMessageExample", 0, 5000);
System.out.println("Server restarted.");
// Step 11. Now the server is restarted we can recreate the JMS Objects, and start the new connection
initialContext = new InitialContext();
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.getLongProperty("_AMQ_LARGE_SIZE") +
" 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.
outputFile = new File("huge_message_received.dat");
try (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_AMQ_SaveStream", bufferedOutput);
}
System.out.println("File streamed to disk. Size of received file on disk is " + outputFile.length());
} finally {
// Step 12. Be sure to close our resources!
if (initialContext != null) {
initialContext.close();
}
if (connection != null) {
connection.close();
}
if (inputFile != null && deleteFiles) {
inputFile.delete();
}
if (outputFile != null && deleteFiles) {
outputFile.delete();
}
ServerUtil.killServer(server);
}
}
private static void createFile(final File file, final long fileSize) throws IOException {
FileOutputStream fileOut = new FileOutputStream(file);
try (BufferedOutputStream buffOut = new BufferedOutputStream(fileOut)) {
byte[] outBuffer = new byte[1024 * 1024];
for (long i = 0; i < fileSize; i += outBuffer.length) {
buffOut.write(outBuffer);
}
}
}
}