在继承JPanel里面是否能在其本身里面加背景

Question

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;public class CursorTest
    extends JFrame {
   ChessBoard p;  private JButton b = new JButton("Void");
  public CursorTest() 
  {
    super("cursorTest");
    this.setSize(300, 200);
    p=new ChessBoard();
    Container cp = getContentPane();
    cp.add(BorderLayout.CENTER, p);
    cp.add(BorderLayout.SOUTH, b);
    this.setVisible(true);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }
  public static void main(String args[]) 
  {
    CursorTest test = new CursorTest();
  }}
 class ChessBoard extends JPanel
{
  }

Answer 1

比如说JPanel里加一张图片，使得JPanel里的其他组件更美观．我的要求是在不能改变JPanel的前提．不能在JPanel里面加一个组件，在组件上显示图片，只能在JPanel下加．谢谢！！！

Answer 2

import java.awt.event.*;                                
import javax.swing.*;                                   
import java.awt.*;                                      
                                                        
public class CursorTest  extends JFrame {                                    
   ChessBoard p;                                        
                                                        
  private JButton b = new JButton("Void");              
  public CursorTest()                                   
  {                                                     
    super("cursorTest");                                
    this.setSize(300, 200);                             
    p=new ChessBoard();                                 
    Container cp = getContentPane();                    
    cp.add(BorderLayout.CENTER, p);                     
    cp.add(BorderLayout.SOUTH, b);                      
    this.setVisible(true);                              
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }                                                    
  public static void main(String args[])                
  {                                                     
    CursorTest test = new CursorTest();                 
  }                                                     
                                                        
}                                                       
 class ChessBoard extends JPanel                        
{       
public ChessBoard()
{
super();
setBackground(Color.RED);  // 背景为红色
}
                                             
 }

Answer 3

overwrite这个方法
public void paintComponent(Graphics g) {
                  String url="你放置图片的地址";
                  image = (new ImageIcon(url)).getImage();
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
if (image != null) {
g2d.drawImage(image, 0, 0, this.WIDTH,this.HEIGHT,this);
System.out.println("this.WIDTH: "+ this.RIGHT_ALIGNMENT);
System.out.println("this.HEIGHT: "+ this.BOTTOM_ALIGNMENT);
}
}