Java clip.open hangs indefinitely

Question

I am trying to open a .wav file and play it using a Clip. But when I call myClip.open(...), the thread freezes and never resumes. No errors are thrown. Here is a simple version of my code:

try {
    AudioInputStream mySound = AudioSystem.getAudioInputStream(new File("sounds/myAudioFile.wav"));
    myClip = AudioSystem.getClip();
    myClip.open(mySound); //This is where it hangs
    myClip.start(); //This is never executed
} catch (Exception e) {e.printStackTrace();}

EDIT: An alternate version of my code (also doesn't work):

Clip myClip = null;

new Thread(new Runnable() {
     public void run() {
          try {
              AudioInputStream mySound = AudioSystem.getAudioInputStream(new File("sounds/myAudioFile.wav"));
              myClip = AudioSystem.getClip();
              System.out.println("Before open");
              myClip.open(mySound); //This is where it hangs
              System.out.println("After open"); //never executed
              //This thread runs indefinitely, whether or not clip.start() is called
          } catch (Exception e) {e.printStackTrace();}
     }
}).start();

try{  Thread.sleep(1000);  }catch(Exception e){} //give it a second to open

myClip.start(); //Executed, but doesn't make a sound
System.out.println("Started clip");

Output:

Before open
Started clip

I know what causes this, but I can't figure out a way the thread from freezing eternally. It freezes because the sound drivers on my computer occasionally stop working, and prevent any sound from any program from playing. I just need some way to force the clip.open method (or thread) to timeout after about 2 to 3 seconds. Calling clip.start() in another thread works, but plays no sound because the clip hasn't opened. And the thread containing clip.open(...) runs forever, even after calling clip.start().

Try to write it in a thread. Otherwise it will block your main thread, which feels like freezing. — Boola, Jun 21 '16 at 06:14

Boola · Answer 1 · 2016-06-21T06:24:05.300

0

public static synchronized void playSound(final String url) {
  new Thread(new Runnable() {
  // The wrapper thread is unnecessary, unless it blocks on the
  // Clip finishing; see comments.
    public void run() {
      try {
        Clip clip = AudioSystem.getAudioInputStream(new File("sounds/myAudioFile.wav"));       // you can pass it in url
        clip.open(inputStream);
      } catch (Exception e) {
        System.err.println(e.getMessage());
      }
    }
  }).start();
}

One more point: You haven't started your clip. use clip.start() In this case, you won't have to use different thread as clip.start() spawns a new thread itself.

edited Jun 21 '16 at 06:24

answered Jun 21 '16 at 06:17

Boola

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14

That does fix my freezing problem, but it also creates a new thread that will never end. I suppose that isn't a problem, right? – Daniel Williams Jun 21 '16 at 06:52
I wrote already a way to avoid that. As soon as you use clip.start(), it will spawn a new thread. actual problem in your code is you are just opening the clip but never starting it. so it waits for clip to start. – Boola Jun 21 '16 at 06:56
May be this can help :(though I am not sure it will solve your problem or not): http://stackoverflow.com/questions/5241822/is-it-good-way-to-stop-java-thread-forcefully – Boola Jun 22 '16 at 07:17

Java clip.open hangs indefinitely

1 Answers1