找着书上写，第一回运行有声音，接下来就没了

package csxc;

import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.io.File;
import java.net.URI;
import java.net.URL;

import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.Box;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.KeyStroke;

public class csxc4 extends Applet{
			public static void main(String[] asd){
					new MusicWindow1();
				}

}
			class MusicWindow1 extends JFrame{
						Police listener;
						JButton musicButton[];
						File musicFile;
						URI uri;
						URL url;
						AudioClip clip;
						String[] musicName={"E:/1.wav","E:/1.wav","E:/1.wav","E:/1.wav","E:/1.wav","E:/1.wav","E:/1.wav"};
						MusicWindow1(){
						musicButton=new JButton[7];
						Box musicBox=Box.createHorizontalBox();
						listener=new Police();
						for(int i=0;i<musicButton.length;i++){
						musicButton[i]=new JButton(""+(i+1));
						/**
						 * 首先这里你没有加事件监听。然后这个appletaudio 好像不能放MP3，能放wav,你可以试试
						 */
						musicButton[i].addActionListener(new Police());
						musicBox.add(musicButton[i]);
						InputMap inputmap=musicButton[i].getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
						inputmap.put(KeyStroke.getKeyStroke(((""+(i+1)))),"dog");
						ActionMap actionmap=musicButton[i].getActionMap();
						actionmap.put("dog", listener);
						}
						setLayout(new FlowLayout());
						add(musicBox);
						setBounds(120,125,290,150);
						setVisible(true);
						setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
						
						}

	class Police extends AbstractAction{

			@Override
			public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			JButton button=(JButton) e.getSource();
			if(clip!=null) clip.stop();
			for(int i=0;i<musicButton.length;i++){
			if(button==musicButton[i]){
			
				System.out.println(i);
				musicFile=new File(musicName[i]);
				uri=musicFile.toURI();
			try{url=uri.toURL();
				
			}catch(Exception exp){
			
			}
			clip=Applet.newAudioClip(url);
				clip.play();
			}
			}
			
			}
}
}