和KeyPressed有关的这个程序出错了？

[huyanqieyu]

import java.awt.event.*;
import java.awt.*;

public class ww {
public static void main(String[] args) {
Button b = new Button("Press Me!");
b.addKeyListener(new KeyHandler());
Frame f = new Frame("MyFrame");
f.add(b);
f.setVisible(true);
}
}

class KeyHandler implements KeyListener {

public void keyPressed(KeyEvent e)
{
System.out.println("Action occurred");
}
}

[quanc_java]

import java.awt.event.*;
import java.awt.*;

public class ww {
public static void main(String[] args) {

Frame f = new Frame("MyFrame");
f.setSize(100,100);
Button b = new Button("Press Me!");
b.addKeyListener(new KeyHandler());
f.add(b);

//关闭窗口
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
f.setVisible(true);
}
}

class KeyHandler implements KeyListener {

public void keyPressed(KeyEvent e)
{
System.out.println("Action occurred");
}
public void keyTyped(KeyEvent e){

}
public void keyReleased(KeyEvent e){

}
}
因为你所实现的接口KeyListener中定义了三个方法keyPressed(KeyEvent e) ，keyTyped(KeyEvent e)，keyReleased(KeyEvent e),所以你在具体让一个类实现此接口的时候，你必须得实现其中的这些方法．还有因为keyListener是处理键盘事件的，不知你用个Button按钮是什么意思. 你可以用处理鼠标事件的接口MouseListener