自生成图片验证码Servlet

 package com.woniuxy.busniess.servlet;

 import java.awt.*;
 import java.awt.geom.*;
 import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.util.Random;
 import javax.imageio.ImageIO;
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;

 /**
 * 图片验证码生成
 * @author xumin
 *
 */
 @WebServlet("/PictureCheckCodeServlet")
 public class PictureCheckCodeServlet extends HttpServlet {

     // 获取随机颜色

     /**
      *
      */
     private static final long serialVersionUID = 1L;

     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);

     }

     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 = 26;

         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(3)) {

             case 1:

                 itmp = random.nextInt(26) + 65; // 生成A~Z的字母

                 ctmp = String.valueOf((char) itmp);
                 if (ctmp.equalsIgnoreCase("o")) {
                     ctmp = "A";
                 }

                 break;

             default:

                 itmp = random.nextInt(10) + 48; // 生成0~9的数字

                 ctmp = String.valueOf((char) itmp);
                 if (ctmp.equalsIgnoreCase("0")) {
                     ctmp = "1";
                 }

                 break;

             }

             sRand += ctmp;

             Color color = new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110));

             g.setColor(color);

             // 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();
         //System.out.println("randCheckCode:"+session.getAttribute("randCheckCode"));

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

     }

 }