如何防止 JPanel 将上次单击的 J Components 对象复制到其面板中？

如何解决如何防止 JPanel 将上次单击的 J Components 对象复制到其面板中？

我正在为我的大学做最后的项目。而且我没有太多的 Java 知识来调试代码。该错误是有问题的。我将在这里删除 3 个类 Java 代码，Drawing Panel、Jframe 和 main() 一个。

main() 代码：

package test;
public class main {
    public static void main(String[] agrs) {
          Aaa a = new Aaa();
    }
}

Aaa 代码（IDK 命名）：

package test;

import java.awt.*;

import javax.swing.*;

public class Aaa extends JFrame{
    JPanel panel = new JPanel();
    JLabel text = new JLabel("please try click on the button first,then drawing,then click and draw again.");
    JButton button = new JButton("bug here");
    DrawingPanel drawingPanel = new DrawingPanel();
    
    public Aaa() {
        this.add(panel,BorderLayout.norTH);
        panel.setBackground(Color.WHITE);
        panel.add(text);
        panel.add(button);
        this.add(drawingPanel,BorderLayout.CENTER);
        
        this.setSize(700,500);
        this.setTitle("Submit to StackOverFlow");
        this.setLocationRelativeto(null);
        this.setVisible(true);
        this.setResizable(false);
        this.setDefaultCloSEOperation(EXIT_ON_CLOSE);
    }
}

DrawingPanel() 类（个人怀疑这是 bug 所在。我在不同的项目中使用过它，它也有相同的 bug）：

package test;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class DrawingPanel extends JPanel implements MouseListener,MouseMotionListener{
    boolean mouse = false;
    private int x1,y1,x2,y2;
    protected int resetCount = 0;
    
    public DrawingPanel() {
        this.addMouseListener(this);
        this.addMouseMotionListener(this);
    }
    
    protected void paintComponent(Graphics g) {
        if (mouse) {
            if (resetCount == 0 ) {
                super.paintComponent(g);
                resetCount++;
            }
            g.setColor(Color.black);
            g.drawLine(x1,y2);
        }
    }
     
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {
    }
    public void mouseExited(MouseEvent e) {}
    
    public void mouseReleased(MouseEvent e) {
        mouse = false;
    }
    
    public void mousepressed(MouseEvent e) {
        mouse= true;
        x2 = (int) e.getPoint().getX();
        y2 = (int) e.getPoint().getY();
    }
    
    public void mouseMoved(MouseEvent e) {
    }
    public void mouseDragged(MouseEvent e) {
        x1 = x2;
        y1 = y2;
        x2 = (int) e.getPoint().getX();
        y2 = (int) e.getPoint().getY();
        repaint();
    }

}

将这 3 个代码一起运行，DrawingPanel 绘图面板会将 JButton 按钮复制到其面板的左上角。如果有 2 个或更多按钮，它将复制最后一个。第一次单击的按钮不会复制到其面板上。有时这个错误也适用于 JTextField。此外，我们可以在面板上绘画！这是图片 this

如果有人知道如何调试这个，我会全力修复它们，非常感谢！