Java画笔的简单实用方法

import java.awt.Graphics;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import javax.swing.JFrame;import javax.swing.JPanel;/** * 画笔的初始用 *  * @author M_WBCG *  */public class paintBrush extends JFrame implements MouseListener {	// 画笔初始化	Graphics g;	// 坐标的起点和终点的初始化	int x1, y1, x2, y2;	public paintBrush() {		// TODO Auto-generated constructor stub		// 创建获得画笔的面板		JPanel drawPanel = new JPanel();		// 给窗体添加面板		add(drawPanel);		setTitle("画笔");		setSize(500, 500);		setVisible(true);		// 画笔获取要在可见之后,设置成全局属性		g = drawPanel.getGraphics();		drawPanel.addMouseListener(this);	}	public static void main(String[] args) {		new paintBrush();	}	@Override	public void mouseClicked(MouseEvent e) {		// TODO Auto-generated method stub	}	@Override	public void mousePressed(MouseEvent e) {		// TODO Auto-generated method stub		x1 = e.getX();		y1 = e.getY();	}	@Override	public void mouseReleased(MouseEvent e) {		// TODO Auto-generated method stub		x2 = e.getX();		y2 = e.getY();		g.drawLine(x1, y1, x2, y2);		x1 = x2 = y1 = y2 = 0;	}	@Override	public void mouseEntered(MouseEvent e) {		// TODO Auto-generated method stub	}	@Override	public void mouseExited(MouseEvent e) {		// TODO Auto-generated method stub	}}