Using Compressed JMS Messages

If you are publishing large XML messages onto a JMS topic or queue, compression will give you much better performance because less data is sent over the network. Also, your JMS server can hold more messages and there is less risk of running out of memory. XML messages are great candidates for compression, due to the repetitive nature of XML.

Compressing JMS messages
The following code shows how you can create a compressed BytesMessage and publish it onto a topic:

InputStream in = null;
GZIPOutputStream out = null;
try {
  ByteArrayOutputStream bos = new
                            ByteArrayOutputStream(1024 * 64);
  out = new GZIPOutputStream(bos);

  String filename = "input.xml";
  in = new BufferedInputStream(new FileInputStream(filename));

  byte[] buf = new byte[1024 * 4];
  int len;
  while ((len = in.read(buf)) > 0) {
      out.write(buf, 0, len);
  }
  out.finish();

  //publish it
  BytesMessage msg = session.createBytesMessage();
  msg.writeBytes(bos.toByteArray());
  publisher.publish(msg);
}
catch (IOException e) {
  e.printStackTrace();
}
finally {
  if (in != null) {
    try {
        in.close();
    }
    catch (IOException ignore) {
    }
  }
  if (out != null) {
    try {
        out.close();
    }
    catch (IOException ignore) {
    }
  }
}

Decompressing JMS messages
The following code shows how you can decompress a JMS BytesMessage when your subscriber receives it and write it to file:

if (mesg instanceof BytesMessage) {
 final BytesMessage bMesg = (BytesMessage) mesg;

 byte[] sourceBytes;
 try {
    sourceBytes = new byte[(int) bMesg.getBodyLength()];
    bMesg.readBytes(sourceBytes);
    System.out.println("Read " + sourceBytes.length + " bytes");
 }
 catch (JMSException e1) {
    throw new RuntimeException(e1);
 }
 GZIPInputStream in = null;
 OutputStream out = null;
 try {
    in = new GZIPInputStream(
         new ByteArrayInputStream(sourceBytes));
    String filename = "message.xml";
    out = new FileOutputStream(filename);
    byte[] buf = new byte[1024 * 4];
    int len;
    while ((len = in.read(buf)) > 0) {
        out.write(buf, 0, len);
    }
    System.out.println("Wrote to " + filename);
 }
 catch (IOException e) {
    e.printStackTrace();
 }
 finally {
    if (in != null)
        try {
            in.close();
        }
        catch (IOException ignore) {
        }
    if (out != null)
        try {
            out.close();
        }
        catch (IOException ignore) {
        }
 }
}