import java.awt.*;import java.awt.event.*;import javax.swing.*;public class MouseDemo extends JFrame implements MouseListener, MouseMotionListener { int flag; //flag=1代表Mouse Moved,flag=2代表Mouse Dragged int x = 0; int y = 0; int startx, starty, endx, endy;//起始坐標與終點坐標 public MouseDemo() { Container contentPane = getContentPane(); contentPane.addMouseListener(this); contentPane.addMouseMotionListener(this); setSize(300, 300); show(); addWindowListener(new WindowAdapter() {  public void windowClosing(WindowEvent e) {  System.exit(0);  } }); } /*由mousePressed(),mouseReleased()取得鼠標拖曳的開始與結束坐標*/ public void mousePressed(MouseEvent e) { startx = e.getX(); starty = e.getY(); } public void mouseReleased(MouseEvent e) { endx = e.getX(); endy = e.getY(); } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } public void mouseClicked(MouseEvent e) { } /*mouseMoved(),mouseDragged()取得鼠標移動的每一個坐標，并調用repaint()方法*/ public void mouseMoved(MouseEvent e) { flag = 1; x = e.getX(); y = e.getY(); repaint(); } public void mouseDragged(MouseEvent e) { flag = 2; x = e.getX(); y = e.getY(); repaint(); } public void update(Graphics g) { g.setColor(this.getBackground()); g.fillRect(0, 0, getWidth(), getHeight()); //清除當前的窗口內容 paint(g); } public void paint(Graphics g) { g.setColor(Color.black); if (flag == 1) {  g.drawString("鼠標坐標：(" + x + "," + y + ")", 10, 50);  g.drawLine(startx, starty, endx, endy); } if (flag == 2) {  g.drawString("拖曳鼠標價坐標：(" + x + "," + y + ")", 10, 50);  g.drawLine(startx, starty, x, y); } } public static void main(String[] args) { new MouseDemo(); }}