applet 运行时出问题了

来源：互联网发布：中国电信云计算编辑：程序博客网时间：2024/04/28 02:52

我编写了个applet小程序，结果在网页上出不来，大家帮我看看吧。

我第一个写的是html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>第一个网页</title>
</head>

</body>
</html>

我第二个写的是applet

import java.applet.Applet;
import java.awt.Graphics;
public class Exam4_1 extends Applet
{

  String str;
  public void init()
  {
   str="here is an Applet";
  }
  public void paint(Graphics g)
  {
   g.drawString(str, 100, 100);
  }

}

结果出现了下面问题，大家帮帮忙吧！

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException: component argument pData
at sun.awt.windows.Win32SurfaceData.initOps(Native Method)
at sun.awt.windows.Win32SurfaceData.<init>(Win32SurfaceData.java:448)
at sun.awt.windows.Win32SurfaceData.createData(Win32SurfaceData.java:316)
at sun.awt.Win32GraphicsConfig.createSurfaceData(Win32GraphicsConfig.java:357)
at sun.awt.windows.WComponentPeer.replaceSurfaceData(WComponentPeer.java:332)
at sun.awt.windows.WComponentPeer.replaceSurfaceData(WComponentPeer.java:313)
at sun.awt.windows.WComponentPeer$2.run(WComponentPeer.java:353)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)