java applet上关于HTML运行的问题
package chapter16;
import chapter13.MessagePanel;
import javax.swing.*;
public class DisplayMessageApp extends JApplet{
public void init(){
String message=getParameter("MESSAGE");
int x=Integer.parseInt(getParameter("X"));
int y=Integer.parseInt(getParameter("Y"));
MessagePanel messagePanel=new MessagePanel(message);
messagePanel.setXc(x);
messagePanel.setYc(y);
add(messagePanel);
}
}
<!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=UTF-8">
<title>DispalymessageApp</title>
</head>
<body>
<p>This applets gets a message from the HTML page and displays it.</p>
<applet
code="DisplayMessageApp.class"
width=200
height=50
alt="you must have a java-2"
>
<param name=MESSAGE value="welcome to java" />
<param name=X value=20 />
<param name=Y value=20 />
</applet>
</body>
</html>
完全照书上来的，可是总是提示我如下：
java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at chapter16.DisplayMessageApp.init(DisplayMessageApp.java:7)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
求救啊！！！！！！ Java HTML Applet --------------------编程问答-------------------- 目测X和Y没传过来。
补充：Java , Eclipse
