Java paintComponent调整大小/最小化将删除除最后绘制的组件之外的所有组件

Question

标题中指定了问题。我跑了，在这里和那里做几行。当我调整窗口大小或最小化窗口时，除了绘制的最后一行之外的所有内容都将从jframe窗口中删除。这是一个更大的相册计划的一部分。最终，我希望能够保存绘图并添加到相册中。我相信下面的代码就是问题所在。我这整个晚上一直在摸不着头脑。我想如果我创建了两个arraylists并遍历它们，repaint（）会重新绘制所有内容，但事实并非如此。请帮忙！这是我的代码：

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Draw extends JPanel implements MouseListener, MouseMotionListener, ActionListener
{
private static final long serialVersionUID = 1L;
private ArrayList<ArrayList<Point>> lines;
private ArrayList<Point> points;
private Graphics g;
private Button clearButton;

public Draw()
{
    clearButton = new Button("Clear slate");
    g = getGraphics();
    points = new ArrayList<Point>();
    lines = new ArrayList<ArrayList<Point>>(); 
    setPreferredSize(new Dimension(500, 500));
    setBounds(0,0,500,500);
    addMouseListener(this);
    addMouseMotionListener(this);

    clearButton.addActionListener(this);        

    this.add(clearButton, BorderLayout.SOUTH);
}
@Override
public void mouseClicked(MouseEvent e) {}

@Override
public void mouseDragged(MouseEvent e) 
{
    // TODO Auto-generated method stub
    points.add(e.getPoint());
    lines.add(points);
    repaint();      
}

public void paint(Graphics g)
{
    super.paintComponents(g);

    for(ArrayList<Point> p : lines)
    {
        for(int i = 0; i < points.size()-1; i++)
            g.drawLine(points.get(i).x, points.get(i).y, points.get(i+1).x, points.get(i+1).y);
    }
}

@Override
public void mouseEntered(MouseEvent e)  {}
@Override
public void mouseExited(MouseEvent e)   {}
@Override 
public void mousePressed(MouseEvent e)  
{
    points = new ArrayList<Point>();
    points.add(e.getPoint());
    repaint();
}
@Override
public void mouseReleased(MouseEvent e) {}
@Override
public void mouseMoved(MouseEvent e)    {}
@Override
public void actionPerformed(ActionEvent evt) 
{
    if(evt.getSource()== clearButton)
    {
        lines.clear();
        points.clear();
        repaint();
    }

}




}

主要方法：

import javax.swing.JFrame;

public class MainDriver 
{
    public static void main(String a[])
    {
    JFrame frame = new JFrame();
    Draw d = new Draw();
    frame.add(d);
    frame.pack();

    frame.setVisible(true);
}

}