java代码空指针

import java.applet.*;
import java.net.*;
public class TestApplet
{
public static void main(String[] args)throws Exception
{
try
{
Applet a = new Applet();
a.getAccessibleContext();
String str = a.getAppletInfo();
System.out.println(str);
System.out.println(a.isActive());
URL u = new URL("http://17iyy.jmppcyy.cn/2/166241.mp3");
a.play(u,"水煮鱼");
}catch(Exception e){e.printStackTrace();}
}
}上面代码空指针错误，我只是想实现运行程序，自动播放音乐该怎么实习呢，麻烦大家看一下，在线等待谢谢

我对APPLET了解不多，把你的程序debug了下。看到上面得到的就是a好像就是空的啊？

import java.applet.*;
import java.net.*;
public class TestApplet extends Applet {
public static void main(String[] args)throws Exception {
try {
TestApplet a = new TestApplet();
a.getAccessibleContext();
String str = a.getAppletInfo();
System.out.println(str);
System.out.println(a.isActive());
URL u = new URL("http://17iyy.jmppcyy.cn/2/166241.mp3");
a.play(u,"水煮鱼");
}catch(Exception e){e.printStackTrace();}
}
}

错误：
java.lang.NullPointerException
at java.applet.Applet.getAppletContext(Applet.java:181)
at java.applet.Applet.getAudioClip(Applet.java:289)
at java.applet.Applet.getAudioClip(Applet.java:309)
at java.applet.Applet.play(Applet.java:395)
at A.main(A.java:13)