Help with Mp3 player

[Crathes]

I think only once.
first I have the public class:

public class oppg2vaar2011Design extends JFrame implements ActionListener{

then i have this:

public oppg2vaar2011Design() {

and later i make it visible with this:

public static void main(String[] args) {
		oppg2vaar2011Design app = new oppg2vaar2011Design();
		app.setVisible(true);

[Crathes]

I have been checking the code, but i cant find anything wrong.

I tried removing stopthread.start();
This eliminated the error message, but it the playthread.interrupt() doesn't seem to do anything. Am doing the interrupt wrong?

[Fubarable]

I don't know as it's a bit of code and code I can't run. Until someone smarter comes here, you will likely want to simplify and isolate to try to get to the root of the problem.

[Crathes]

Thanks for trying :)
What do you mean with code you cant run?

I don't really know how i can simplify it. I need the threads because i have to be able to do press buttons while the program is doing something, and i think the threads are the source of the problem.

[Fubarable]

Thanks for trying :)
What do you mean with code you cant run?

I don't really know how i can simplify it. I need the threads because i have to be able to do press buttons while the program is doing something, and i think the threads are the source of the problem.

Your code depends on the AdvancedPlayer class and outside resources that I don't have access to including images and such.

[Crathes]

Its not hard to get, if you want to try. link

[Toll]

Try adding a "System.out.println(player)" just before you execute the "player.stop()". That will tell you if player really is null, or if there's something else fishy around.

[Crathes]

This is the message i get from System.out.println(player):
javazoom.jl.player.advanced.AdvancedPlayer@ 5d6d2633

[Toll]

That means that it's not player that is null; thus it's something else that's throwing the nullpointerexception. Try putting another System.out.println("stuff" right after the player.stop() line. If that one fires, then it's definitely not that line. Otherwise... I assume that AdvancedPlayer isn't something you've written yourself?

[Toll]

Looking closer at the stacktrace, I'm starting to lean more and more towards something in AdvancedPlayer throwing a NullPointerException. Perhaps it is intended and indicative of something specific? Read through the docs to see if there are any hints in there about why it throws it.

[Fubarable]

Looking closer at the stacktrace, I'm starting to lean more and more towards something in AdvancedPlayer throwing a NullPointerException. Perhaps it is intended and indicative of something specific? Read through the docs to see if there are any hints in there about why it throws it.

Like I said -- wait for someone smarter to come along, and here he is. :)

[Crathes]

That means that it's not player that is null; thus it's something else that's throwing the nullpointerexception. Try putting another System.out.println("stuff" right after the player.stop() line. If that one fires, then it's definitely not that line. Otherwise... I assume that AdvancedPlayer isn't something you've written yourself?

When i put System.out.println("stuff") right after player.stop() i get nothing.
When i put it in the if statement for the stop button, right after trying to stop and start the two threads it writes out "stuff".

No, the advanced player is an external library i downloaded from Javazoom.net.

Looking closer at the stacktrace, I'm starting to lean more and more towards something in AdvancedPlayer throwing a NullPointerException. Perhaps it is intended and indicative of something specific? Read through the docs to see if there are any hints in there about why it throws it.

I cannot find any information about AdvancedPlayer throwing NullPointerException. The only Exception they have information on is the JavaLayerException.

[Toll]

Well, right now everything points towards something within AdvancedPlayer throwing a NullPointerException. The documentation doesn't help much either, unfortunately.. I can far from guarantee that it will help, but try adding a PlaybackListener to the player. It could be that it doesn't check if the listener is null when trying to stop the player. If that doesn't work... well, can't help much.

[Toll]

Looking through the code, it's no wonder you get a NPE there without a listener. This is all the code that is executed in the stop() function:

	public void stop()
	{
		listener.playbackFinished(createEvent(PlaybackEvent.STOPPED));
		close();
	}

So yeah... Add a listener and the NPE should go away. Hopefully. You can also try calling close() instead of stop().

[Crathes]

EDIT: never mind

[Crathes]

When i added the playbackListener nothing new happened. I'm not sure if i did it correctly though. I'll update the code in OP to include it.

When i say player.close() instead of player.stop(), the player actually stops. I hope i will be able to use this method in a pause button as well.

[Crathes]

I have spent several hours trying to figure out how to do a button with a pause function for my mp3 player now, and I do not have any clue. Do any of you guys have any ideas?