请问:com.mkjdelove.www.ScribllePane1不是抽象的，未能覆盖java.awt.event.MouseLister中的抽象方法mouseClcked(java.awt.event.MouseEv

原程序：
package com.mkjdelove.www;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.MouseListener;
public class ScribblePane1 extends JPanel implements MouseListener,MouseMotionListener{
protected int last_x,last_y;
public ScribblePane1(){
this.addMouseListener(this);
this.addMouseMotionListener(this);
setPreferredSize(new Dimension(450,200));
}
public void mousePressed(MouseEvent e){
last_x=e.getX();
last_y=e.getY();
}
public void mouseDragged(MouseEvent e){
int x=e.getX();
int y=e.getY();
this.getGraphics().drawLine(last_x,last_y,x,y);
last_x=x;
last_y=y;
}
public void mouseReleased(MouseEvent e){}
public void mouseClick(MouseEvent e){}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mouseMoved(MouseEvent e){}
}