Question

The play method below is from a class which, upon instantiation, reads a .wav file into a byte array called data, and stores the sound format in an AudioFormat object called format.

I have a program that calls play from a java.util.Timer. When I go into the folder with all the relevant .class files and I run the program using the command java MainClass, everything works as expected. However, when I put all the .class files in an executable .jar and run the program using the command java -jar MyProgram.jar, sounds played using the play method are cut off after something like 50 to 150 ms.

public void play() throws LineUnavailableException {
    final Clip clip = (Clip)AudioSystem.getLine(new DataLine.Info(Clip.class, format));
    clip.open(format, data, 0, data.length);
    new Thread() {
        public void run() {
            clip.start();
            try {
                Thread.sleep(300); // all sounds are less than 300 ms long
            } catch (InterruptedException ex) { /* i know, i know... */ }
            clip.close();
        }
    }.start();
}

A few comments:

• I’ve tried increasing the sleep time in the play method up to 1000 ms, with no change in behavior.

• Timing the Thread.sleep using System.nanoTime confirms that the thread is sleeping exactly as long as expected.

• Since the sound file to be played is pre-loaded into memory, I don’t think the act of extracting the sound resource from the .jar can be causing the problem.

• I’ve tried running the program from both inside and outside the jar using the memory pool size options -Xms2m and -Xmx64m (separately), with no change in behavior.

I’m running OpenJDK Java 6 on Ubuntu 11.04. Any idea what’s going on?

Answer 1

It is likely the loading of the byte[] that is the problem.