生成验证码

最新推荐文章于 2023-01-11 10:18:58 发布

wen200507048

最新推荐文章于 2023-01-11 10:18:58 发布

阅读量342

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/wen200507048/article/details/44622721

这个也是之前从别人那里拿过来用的，各网站也有不少这样的例子了，只作为自己有需要的时候用

public class AuthImage extends HttpServlet {

   private static final long serialVersionUID = 1L;
   private int imageWidth = 100;
   private int imageHeight = 30;
   private int codeNumber = 4;
   private int backGround = 40;

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       response.setHeader("Pragma", "no-cache");
       response.setHeader("Cache-Control", "no-cache");
       response.setDateHeader("Expires", 0);
       response.setContentType("image/jpeg");
       BufferedImage bufferedImage = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_BGR);
       Graphics2D g = bufferedImage.createGraphics();
       g.setColor(Color.WHITE);
       g.fillRect(0, 0, imageWidth - 1, imageHeight - 1);
       Random random = new Random();
       for (int i = 0; i < backGround; i++) {
           int red = random.nextInt(256);
           int green = random.nextInt(256);
           int blue = random.nextInt(256);
           g.setColor(new Color(red, green, blue));
           int start_X = random.nextInt(imageWidth);
           int start_Y = random.nextInt(imageHeight);
           if (random.nextInt(5) % 3 == 0) {
               int r = random.nextInt(10);
               int startAngle = random.nextInt(360);
               int arcAngle = random.nextInt(360);
               g.drawArc(start_X, start_Y, r, r, startAngle, arcAngle);
           } else {
               int change_X = random.nextInt() % 6;
               int change_Y = random.nextInt() % 6;
               g.drawLine(start_X, start_Y, start_X + change_X, start_Y + change_Y);
           }
       }
       StringBuffer ValidateCode = new StringBuffer();
       // g.setFont(new Font("Blackoak Std", Font.BOLD, imageHeight-2));
       g.setFont(new Font("Tahoma", Font.BOLD, imageHeight - 3));
       for (int i = 0; i < codeNumber; i++) {
           int red = random.nextInt(100) + 50;
           int green = random.nextInt(100) + 50;
           int blue = random.nextInt(100) + 50;
           g.setColor(new Color(red, green, blue));
           String code = null;
           int type = random.nextInt(3);
           if (type == 1) {
               code = String.valueOf((char) (random.nextInt(26) + 65));
           } else if (type == 2) {
               code = String.valueOf((char) (random.nextInt(26) + 97));
           } else {
               code = String.valueOf(random.nextInt(10));
           }
           ValidateCode.append(code);
           g.drawString(code, imageWidth / codeNumber * i + 3, 25);
       }
       request.getSession().setAttribute("validateCode", ValidateCode.toString());
       //LogUtil.i(LogUtil.getTraceInfo(), "验证码：" +ValidateCode.toString());
       ServletOutputStream sos = response.getOutputStream();
       ImageIO.write(bufferedImage, "jpeg", sos);
       bufferedImage = null;
       sos.close();
       random = null;
   }

   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
           IOException {
       doGet(request, response);
   }

}