济南站到北京的火车:请java高手帮我看看程序

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;

public class Addition extends Applet implements ActionListener
{
Label label1 = new Label("+");
Label label2 = new Label("=");
TextField field1 = new TextField(6);
TextField field2 = new TextField(6);
TextField field3 = new TextField(6);
Button button = new Button("相加");

public void init()
{
add(field1);
add(label1);
add(field2);
add(label2);
add(field3);
add(button);
button.addActionListener(this);
}

public void actionPerformed(ActionEvent e)
{
int x=Integer.parseInt(field1.getText())+Integer.parseInt(field2.getText());
field3.setText(Integer.toString(x));
}
}
//<applet code=Addition width=300 height=100></applet>

-----------------以上保存在Addition.java中------------------

在cmd下用javac编译后运行appletviewer Addition.java

import java.lang.Integer;
导入一个Integer包就可以了

你想知道什么??