为什么我的代码执行了两次paintComponent(Graphics page)?

This is getting on my nerves and it probably something silly on my part but I can't figure out why my paintComponent is being called twice, if you run my code it outputs REPEAT? REPEAT? twice, I don't want it to do that.. So why does it do it and how can I fix it?

import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.*;

public class Main extends JPanel {


    public Main()
    {      
     /*code here*/
    }

    public void paintComponent(Graphics page)
    {
     clear(page);

        /*code here*/

        System.out.println("REpEAT?"); 

    }

    protected void clear(Graphics page) {
        super.paintComponent(page);
      }

    public static void main (String[] args)
    {
        JFrame frame = new JFrame ("Circles");
        frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);
        frame.getContentPane().add(new Main());
        frame.setVisible(true);

    }



}

推荐答案

我也打印了两次.

但是，我认为这不必担心.Swing 决定何时需要重新粉刷.例如，如果您调整窗口大小或最小化/最大化，Swing 将重新绘制.它可能取决于您运行的操作系统/硬件.