JAVA创建的窗口关闭不了

package aej;

import java.awt.Frame;

import java.awt.Window;

public class MyTyping {

public static void main(String[] args) {

Frame f = new Frame();

f.setLocationRelativeTo(null);

f.setSize(880, 600);

MyPanel p = new MyPanel();

f.add(p);

f.addKeyListener(p);

p.addKeyListener(p);

Thread t = new Thread(p);

t.start();

//f.show();

f.setVisible(true);

}

}

Frame f = new Frame();

改为

JFrame f = new JFrame();

MyPanel 是自定义的吗？