新手

新手求助!
题目要求 "用鼠标按下时,面板为红色,放开时为白色 "下面是我编的程序,可是我觉得没有错误啊,就是不行,请各位前辈帮小弟解决一下啊,不胜感激!
package   使用鼠标设置背景色;
import   java.awt.*;

import   javax.swing.*;

import   java.awt.event.*;

public   class   GroundPanel   extends   JPanel   implements   MouseListener{



boolean   f1=false;
boolean   f2   =false;

public   GroundPanel(){

addMouseListener(this);

}
public   void   mouseClicked(MouseEvent   e){

 

}

public   void   mouseEntered(MouseEvent   e){

}

public   void   mouseExited(MouseEvent   e){

}

public   void   mouseReleased(MouseEvent   e){

f2=true;
}

public   void   mousePressed(MouseEvent   e){

f1=true;

}

protected   void   paintComponent(Graphics   g){
 
  super.paintComponent(g);
 

if(true==f1)  

  {

 
  System.out.println( "f1   is   true ");
 
  g.setColor(Color.black);
 

f1=false;


}
if(true==f2)  

  {

 
  System.out.println( "f2   is   true ");
 
  g.setColor(Color.red);
 

f2=false;


}




}
}


------解决方案--------------------
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ShowColor
{
JFrame f;
JPanel center;
public ShowColor()
{
f = new JFrame();
Container c = f.getContentPane();
center = new JPanel();
c.add(center, "Center ");
f.setSize(300,300);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent me)
{
center.setBackground(Color.red);
}
public void mouseReleased(MouseEvent me)
{
center.setBackground(Color.white);
}
});
}
public static void main(String args[])
{
new ShowColor();
}
}
------解决方案--------------------
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ShowColor
{
JFrame f;
JPanelColor center;
public ShowColor()
{
f = new JFrame();
Container c = f.getContentPane();
center = new JPanelColor();
c.add(center, "Center ");
f.setSize(300,300);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String args[])
{
new ShowColor();
}
}

class JPanelColor extends JPanel
{

public JPanelColor()
{
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent me)