java applet audioclip没有声音播放

Question

我正在编写一个键盘小程序，但按下按钮时无法播放声音文件。没有出现错误，我已经尝试将文件转换为.au，但它仍然没有播放。请帮忙。

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.applet.*;

public class Keyboard extends Applet
implements ActionListener
{
Button menu;
Button[] black;
Button[] white;
AudioClip[] bnote;
AudioClip[] wnote;

public void init ()
{
    setLayout (null);
    setBackground (Color.orange);
    menu = new Button ("Back to Menu");
    menu.setBounds (20, 200, 100, 30);
    add (menu);

    black = new Button [5];
    int x = 45;
    for (int i = 0 ; i < 5 ; i++)
    {
        if (i == 2 || i == 5 || i == 7 || i == 10)
        {
            x = x + 40;
        }
        black [i] = new Button ();
        black [i].setBounds (x, 20, 30, 90);
        black [i].setBackground (Color.black);
        add (black [i]);
        black [i].addActionListener (this);
        x = x + 40;
    }
    white = new Button [7];
    x = 20;
    for (int i = 0 ; i < 7 ; i++)
    {
        white [i] = new Button ();
        white [i].setBounds (x, 20, 40, 150);
        white [i].setBackground (Color.white);
        add (white [i]);
        white [i].addActionListener (this);
        x = x + 40;
    }

    wnote = new AudioClip [7];
    wnote [0] = getAudioClip (getCodeBase (), "C.wav");
    wnote [1] = getAudioClip (getCodeBase (), "D.wav");
    wnote [2] = getAudioClip (getCodeBase (), "E.wav");
    wnote [3] = getAudioClip (getCodeBase (), "F.wav");
    wnote [4] = getAudioClip (getCodeBase (), "G.wav");
    wnote [5] = getAudioClip (getCodeBase (), "A.wav");
    wnote [6] = getAudioClip (getCodeBase (), "B.wav");

    bnote = new AudioClip [5];
    bnote [0] = getAudioClip (getCodeBase (), "Db.wav");
    bnote [1] = getAudioClip (getCodeBase (), "Eb.wav");
    bnote [2] = getAudioClip (getCodeBase (), "F#.wav");
    bnote [3] = getAudioClip (getCodeBase (), "Ab.wav");
    bnote [4] = getAudioClip (getCodeBase (), "Bb.wav");
}


public void actionPerformed (ActionEvent evt)
{
    int num = 0;
    for (int i = 0 ; i < 7 ; i++)
    {
        if (evt.getSource () == white [i])
        {
            wnote [i].play ();
        }
    }
    for (int i = 0 ; i < 5 ; i++)
    {
        if (evt.getSource () == black [i])
        {
            bnote [i].play ();
        }
    }
}

}