生成验证码

来源：互联网发布：淘宝达人v任务编辑：程序博客网时间：2024/04/29 18:33
public class BufferedImageDemo extends HttpServlet {private static final long serialVersionUID = 1L;    private static final int WIDTH = 120;    private static final int HEIGHT = 35;protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//创建一张图片BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);//得到画笔Graphics g = image.getGraphics();//设置图片的额背景颜色setBackGround(g);//设置边框setBorder(g);//生成线条dawRandomLine(g);//生成汉字dawRandomNum((Graphics2D)g);//设置头 告诉浏览器以哪种格式显示数据response.setContentType("image/jpeg");//将图片写到页面ImageIO.write(image, "jpg", response.getOutputStream());}//设置图片背景颜色private void setBackGround(Graphics g) {//设置图片背景颜色为白色g.setColor(Color.WHITE);//填充图片g.fillRect(0, 0, WIDTH, HEIGHT);}//设置边框private void setBorder(Graphics g) {//设置边框颜色g.setColor(Color.BLUE);//将线条画到图片上g.drawRect(1, 1, WIDTH-2, HEIGHT-2);}//生成随机线条private void dawRandomLine(Graphics g) {//设置线条颜色g.setColor(Color.GREEN);//随机位置生成五个线条for(int i=0;i<5;i++){int x1 = new Random().nextInt(WIDTH);int y1= new Random().nextInt(HEIGHT);int x2 = new Random().nextInt(WIDTH);int y2= new Random().nextInt(HEIGHT);//在图片上画线条g.drawLine(x1, y1, x2, y2);}}//生成汉字private void dawRandomNum(Graphics2D g) throws IOException {//设置汉字颜色g.setColor(Color.BLACK);//设置字体，大小，格式g.setFont(new Font("宋体",Font.BOLD,20));//读取配置文件中的常用汉字String path = BufferedImageDemo.class.getClassLoader().getResource("chinese.properties").getPath();InputStream is = new FileInputStream(path);Properties p = new Properties();p.load(is);String base = p.getProperty("base");int x= 5; //生成4个汉字for(int i=0;i<4;i++){//随机生成汉字旋转角度 -30~+30之间int degree = new Random().nextInt()%30;//从常用汉字中随机找出一个汉字String ch = base.charAt(new Random().nextInt(base.length()))+"";//设置汉字旋转角度，这个方法只有Graphics2D中有g.rotate(degree*Math.PI/180, x, 25);//把汉字写到图片上g.drawString(ch, x, 25);//将角度恢复g.rotate(-degree*Math.PI/180, x, 25);//每个汉字之间隔30，再写下一个汉字x+=30;}}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}}
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