Java에서 버튼 클릭을 사용하여 JPanel에 선을 그리는 방법은 무엇입니까?

public void paint(Graphics graphics)
{
    graphics.drawLine(10, 20, 300, 310);
}

public class MouseHandler extends MouseAdapter {

    @Override
    public void mouseClicked(MouseEvent arg0) {


        /////////////


    }
}

JLabel label = new JLabel("New label");
label.addMouseListener(new MouseHandler() {
   @Override
   public void mouseClicked(MouseEvent arg0) {


    /////////////


   }
});
contentPane.add(label);

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;

public class Main {

    private ArrayList<Point> points = new ArrayList<>();
    private boolean drawing;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Main().display();
            }
        });
    }

    private void display() {
        JFrame f = new JFrame("LinePanel");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel();
        panel.setPreferredSize(new Dimension(640, 480));
        panel.addMouseListener(new MouseHandler());
        panel.addMouseMotionListener(new MouseHandler());
        f.add(panel);

        JButton clearButton = new JButton("Clear");
        clearButton.addActionListener(new AbstractAction() {

            @Override
            public void actionPerformed(ActionEvent e) {
                points.clear();
                panel.repaint();
            }
        });
        f.add(clearButton, BorderLayout.SOUTH);

        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    private class MouseHandler extends MouseAdapter {

        @Override
        public void mousePressed(MouseEvent e) {
            drawing = true;
            points.add(e.getPoint());
            panel.repaint();
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            drawing = false;
            panel.repaint();
        }

        @Override
        public void mouseDragged(MouseEvent e) {
            if (drawing) {
                points.add(e.getPoint());
                panel.repaint();
            }
        }
    }
}