java 华容道，为什么键盘事件没有用哦！！各位，拜托了!!
mport java.awt.Color;
import java.awt.Font;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;

/**
 *
 * @author Administrator
 */
public class Test_ShuaRDao {
    public static void main(String[] args) {
        new  HU_R_D("华容道游戏");
    }
    
}

class Person extends JButton implements FocusListener{
    int number;
    Color c=Color.lightGray;
    public Person(int number,String s){
        //super(s);
        this.setText(s);
        this.setFont(new Font("宋体", 1,20));
        this.setBackground(c);
        this.number=number;
        this.addFocusListener(this);
    }
    
     @Override
    public void focusGained(FocusEvent e) {
        this.setBackground(Color.red);
        System.out.println("sdfs");
    }

    @Override
    public void focusLost(FocusEvent e) {
        this.setBackground(c);
    }
    
}

class HU_R_D extends JFrame implements ActionListener,KeyListener,MouseListener{
    Person person[] =new Person[10];
    JButton up ,left,right,below;
    JButton restart=new JButton("重新开始玩");
    public HU_R_D (String s){
        super(s);
        init();
        this.setBounds(20, 20, 500, 650);
        this.setBackground(Color.white);
        this.validate();
        //this.pack();
        this.setVisible(true);
        this.addWindowListener(new WindowAdapter(){
            @Override
            public void windowClosing(WindowEvent e){
                System.exit(0);
            }
        });
    }
    public void init(){