添加声音 但是为什么听不到志声音？

package javaDaZuoYe;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
/*
 * 添加声音 但是为什么听不到志声音？
 */
public class AudioJApplet extends JApplet implements ActionListener{
    AudioClip au;
    JButton JBstart=new JButton("Play");
    JButton JBpause=new JButton("Pause");
    
    public void init(){
        au=getAudioClip(getCodeBase(),"1.mid");
        this.setLayout(new FlowLayout());
        this.add(JBstart);
        this.add(JBpause);
        JBstart.addActionListener(this);
        JBpause.addActionListener(this);
    }
    
    public void actionPerformed(ActionEvent e){
        String cmd=e.getActionCommand();
        if(cmd.equals("Play")){
            au.loop();
        }
        else if(cmd.equals("Pause")){
            au.stop();
        }
        
    }
    
    public void stop(){
        au.stop();
        
    }
    
}