Assuming your program is in Java (...why did you give it three language tags?) You have a few options. You could use a proper synchronization event, e.g.:
// fields
Object playerStopEvent = new Object();
boolean isPlaying;
// in your media player, when playback is complete:
synchronized (playerStopEvent) {
isPlaying = false;
playerStopEvent.notifyAll();
}
// elsewhere, when waiting for playback to complete:
synchronized (playerStopEvent) {
while (isPlaying) {
try {
playerStopEvent.wait();
} catch (InterruptedException x) {
// abort or ignore, up to you
}
}
}
mediaPlayer.stop();
See the official tutorial on Guarded Blocks for more examples.
You could also just have mediaPlayer
call some callback when it is finished, and e.g. disable GUI components when you start playing and re-enable them when the finished callback is called (you could also use an event listener approach here).
Without more info, I recommend the latter, as it won't prevent you from doing other unrelated things (or keep your program from responding at all) while the player is playing, but the former may be more appropriate depending on your situation.
If it's in C or C++ the concept is the same. Use whatever equivalent of condition variables / events you have for the first option, or whatever equivalent of callbacks / listeners / signals+slots you have for the second.