Using Midi

Question

I want a midi to be playing during my game. Board is the display class and the driver is simulation. when i run it, i get a nullpointer exception for i think getDocumentbase()
here is some of the code for board that uses audioclip.
public class Board extends Applet implements KeyListener, AudioClip
AudioClip ac = getAudioClip(getDocumentBase(), "battle.mid");
public Board( )
setSize( 900, 900 );
setVisible( true );
addKeyListener( this );
setBounds( 100, 100, 650, 600 );;
setVisible( true );
ac.loop();
// Play audio clip
public void play()
// Stop playing audio clip
public void stop()
// Play audio clip continuously
public void loop()
}

Answer 1

    public void init() {
        // Load audio clip
        AudioClip ac = getAudioClip(getDocumentBase(), "battle.mid");
        // Play audio clip continuously
        ac.loop();
    }