英文.数字和中文混合的彩色验证码【JSP】

一、编写生成英文，数字和中文混合的彩色验证码的Servlet实现类

（1）创建名称为PictureCheckCode.java的Servlet。

public class PictureCheckCode extends HttpServlet {
    public PictureCheckCode() {
        super();
    }

    public void destroy() {
        super.destroy(); 
    }

    public void init() throws ServletException {
        super.init();
    }
    public void service(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {    
    } 
}   

(2)编写随机生成RGB颜色的方法getRandColor()

// 获取随机颜色
    public Color getRandColor(int s, int e) {
        Random random = new Random();
        if (s > 255) s = 255;
        if (e > 255) e = 255;
        int r = s + random.nextInt(e - s);        //随机生成RGB颜色中的r值
        int g = s + random.nextInt(e - s);        //随机生成RGB颜色中的g值
        int b = s + random.nextInt(e - s);        //随机生成RGB颜色中的b值
        return new Color(r, g, b);
    }

（3）在Service()方法中编写生成彩色验证码的代码

public void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "No-cache");
        response.setDateHeader("Expires", 0);
        // 指定生成的响应是图片
        response.setContentType("image/jpeg");
        int width = 86;
        int height = 22;
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        Graphics2D g2d = (Graphics2D) g;
        Random random = new Random();
        Font mFont = new Font("黑体", Font.BOLD, 17);
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        g.setFont(mFont);
        g.setColor(getRandColor(180, 200));
        // 画随机的线条
        for (int i = 0; i < 100; i++) {
            int x = random.nextInt(width - 1);
            int y = random.nextInt(height - 1);
            int x1 = random.nextInt(6) + 1;
            int y1 = random.nextInt(12) + 1;
            BasicStroke bs = new BasicStroke(2f, BasicStroke.CAP_BUTT,
                    BasicStroke.JOIN_BEVEL);
            Line2D line = new Line2D.Double(x, y, x + x1, y + y1);
            g2d.setStroke(bs);
            g2d.draw(line);
        }
        String sRand = "";
        // 输出随机的验证文字
        String ctmp = "";
        int itmp = 0;
        for (int i = 0; i < 4; i++) {
            //random = new Random(new java.util.Date().getTime() + i);
            switch (random.nextInt(4)) {
            case 1:
                itmp = random.nextInt(26) + 65; // 生成A~Z的字母
                ctmp = String.valueOf((char) itmp);
                break;
            case 2: // 生成汉字
                String[] rBase = { "0", "1", "2", "3", "4", "5", "6", "7", "8",
                        "9", "a", "b", "c", "d", "e", "f" };
                // 生成第1位的区码
                int r1 = random.nextInt(3) + 11;    //生成11到14之间的随机数
                String str_r1 = rBase[r1];
                // 生成第2位的区码
                int r2;
                if (r1 == 13) {
                    r2 = random.nextInt(7);            //生成0到7之间的随机数
                } else {
                    r2 = random.nextInt(16);        //生成0到16之间的随机数
                }
                String str_r2 = rBase[r2];
                // 生成第1位的位码
                int r3 = random.nextInt(6) + 10;    //生成10到16之间的随机数
                String str_r3 = rBase[r3];
                // 生成第2位的位码
                int r4;
                if (r3 == 10) {
                    r4 = random.nextInt(15) + 1;    //生成1到16之间的随机数
                } else if (r3 == 15) {
                    r4 = random.nextInt(15);        //生成0到15之间的随机数
                } else {
                    r4 = random.nextInt(16);        //生成0到16之间的随机数
                }
                String str_r4 = rBase[r4];
                System.out.println(str_r1 + str_r2 + str_r3 + str_r4);
                // 将生成机内码转换为汉字
                byte[] bytes = new byte[2];
                //将生成的区码保存到字节数组的第1个元素中
                String str_r12 = str_r1 + str_r2;
                int tempLow = Integer.parseInt(str_r12, 16);
                bytes[0] = (byte) tempLow;
                //将生成的位码保存到字节数组的第2个元素中
                String str_r34 = str_r3 + str_r4;
                int tempHigh = Integer.parseInt(str_r34, 16);
                bytes[1] = (byte) tempHigh;
                
                ctmp = new String(bytes);    //根据字节数组生成汉字
//                System.out.println("生成汉字:" + ctmp);
                break;
            default:
                itmp = random.nextInt(10) + 48; // 生成0~9的数字
                ctmp = String.valueOf((char) itmp);
                break;
            }
            sRand += ctmp;
            Color color = new Color(20 + random.nextInt(110), 20 + random
                    .nextInt(110), 20 + random.nextInt(110));
            g.setColor(color);
            /** **随机缩放文字并将文字旋转指定角度* */
            // 将文字旋转指定角度
            Graphics2D g2d_word = (Graphics2D) g;
            AffineTransform trans = new AffineTransform();
            trans.rotate(random.nextInt(45) * 3.14 / 180, 15 * i + 8, 7);
            // 缩放文字
            float scaleSize = random.nextFloat() +0.8f;
            if (scaleSize > 1f)    scaleSize = 1f;
            trans.scale(scaleSize, scaleSize);
            g2d_word.setTransform(trans);
            /** ********************* */
            g.drawString(ctmp, 15 * i + 18, 14);

        }
        // 将生成的验证码保存到Session中
        HttpSession session = request.getSession(true);
        session.setAttribute("randCheckCode", sRand);
        g.dispose();
        ImageIO.write(image, "JPEG", response.getOutputStream());
    }

二、配置servlet

<servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>PictureCheckCode</servlet-name>
    <servlet-class>com.PictureCheckCode</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>PictureCheckCode</servlet-name>
    <url-pattern>/PictureCheckCode</url-pattern>
  </servlet-mapping>