public void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        BufferedImage image = new BufferedImage(, ,

                BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

        // 1.设置背景色

        setBackGround(g);

        // 2.设置边框

        setBorder(g);

        // 3.画干扰线

        drawRandomLine(g);

        // 4.写随机数

        drawRandomNum(g);

        // 5.图形写给浏览器

        response.setContentType("image/jpeg");

        ImageIO.write(image, "jpg", response.getOutputStream());

    }

    private void drawRandomNum(Graphics g) {

        g.setColor(Color.RED);

        g.setFont(new Font("宋体",Font.BOLD,));

        //所有汉字区间 \u4e00 \u9fa5

        for (int i = ; i < ; i++) {

            int r=new Random().nextInt();

            int r2=new Random().nextInt();

            g.drawString("好", r, r2);

        }

    }

    private void drawRandomLine(Graphics g) {

        g.setColor(Color.GREEN);

        for (int i = ; i < ; i++) {

            int x1 = new Random().nextInt();

            int y1 = new Random().nextInt();

            int x2 = new Random().nextInt();

            int y2 = new Random().nextInt();

            g.drawLine(x1, y1, x2, y2);

        }

    }

    private void setBorder(Graphics g) {

        g.setColor(Color.BLUE);

        g.drawRect(, , , );

    }

    private void setBackGround(Graphics g) {

        g.setColor(Color.WHITE);

        g.fillRect(, , , );

    }