repaint和paintComponent的问题，急~~~

Question

package com.test;import java.awt.Graphics;
import javax.swing.JPanel;
public class GamePanel extends JPanel{ private static final long serialVersionUID = 1L;
public void display(){
          System.out.println("display");
          this.repaint();
          System.out.println("repaint()");
    }    @Override
    protected void paintComponent(Graphics g) {
        System.out.println("paintComponent");
    }
    public static void main(String[] args){
        GamePanel gamePanel = new GamePanel();
        gamePanel.display();
    }
}
repaint()方法不是会自动调用paintComponent方法吗？为什么我的上面一段程序，不调用paintComponent（）方法呢？
请高手指教，先谢谢了~

Answer 1

javax.swing.JComponent类 
repaint()调用update() 
update()调用paint() 
paint()调用paintComponent(),paintBorder(),及paintChildren()自己搞定了，因为上面的代码，根本就没有开始显示JPanel，既然没有显示，怎么会调用paintComponent（）呢？
可以试试，调试下面一段代码用于理解~package com.test;
import java.awt.Color;
import java.awt.Graphics;import javax.swing.JFrame;
import javax.swing.JPanel;public class GamePanel extends JPanel{ private static final long serialVersionUID = 1L;
public GamePanel(){

} public void display(){
System.out.println("GmaePanel - display");

this.repaint();
} @Override
protected void paintComponent(Graphics g) {

System.out.println("GamePanel - ------------paintComponent");

g.setColor(new Color(0xcfcfcf));
}

@Override
public void paint(Graphics g) {
System.out.println("GamePanel - ------------paint");
super.paint(g);
} @Override
public void update(Graphics g) {
System.out.println("GamePanel - ------------update");
super.update(g);
} public static void main(String[] args){
JFrame frame = new JFrame();
frame.setSize(300,300);
GamePanel gp = new GamePanel();
frame.add(gp);
frame.setVisible(true);
gp.display();
}
}