Struts 验证图片。

Java代码

   1. package cn.com.lough.struts.action; 
   2.  
   3. import java.awt.Color; 
   4. import java.awt.Font; 
   5. import java.awt.Graphics; 
   6. import java.awt.image.BufferedImage; 
   7. import java.util.Random; 
   8.  
   9. import javax.imageio.ImageIO; 
  10. import javax.servlet.ServletOutputStream; 
  11. import javax.servlet.http.HttpServletRequest; 
  12. import javax.servlet.http.HttpServletResponse; 
  13. import javax.servlet.http.HttpSession; 
  14.  
  15. import org.apache.struts.action.Action; 
  16. import org.apache.struts.action.ActionForm; 
  17. import org.apache.struts.action.ActionForward; 
  18. import org.apache.struts.action.ActionMapping; 
  19. import org.apache.commons.lang.RandomStringUtils; 
  20.  
  21. /**
  22.  * MyEclipse Struts Creation date: 01-11-2007
  23.  * 
  24.  * XDoclet definition:
  25.  * 
  26.  * @struts.action validate="true"
  27.  */ 
  28. public class ValidatecodeAction extends Action { 
  29.     /*
  30.      * Generated Methods
  31.      */ 
  32.  
  33.     /**
  34.      * Method execute
  35.      * 
  36.      * @param mapping
  37.      * @param form
  38.      * @param request
  39.      * @param response
  40.      * @return ActionForward
  41.      */ 
  42.     public ActionForward execute(ActionMapping mapping, ActionForm form, 
  43.             HttpServletRequest request, HttpServletResponse response) { 
  44.         try { 
  45.             int width = 50; 
  46.             int height = 18; 
  47.             // 取得一个4位随机字母数字字符串 
  48.             String s = RandomStringUtils.random(4, true, true); 
  49.  
  50.             // 保存入session,用于与用户的输入进行比较. 
  51.             // 注意比较完之后清除session. 
  52.             HttpSession session = request.getSession(true); 
  53.             session.setAttribute("validateCode", s); 
  54.  
  55.             response.setContentType("images/jpeg"); 
  56.             response.setHeader("Pragma", "No-cache"); 
  57.             response.setHeader("Cache-Control", "no-cache"); 
  58.             response.setDateHeader("Expires", 0); 
  59.  
  60.             ServletOutputStream out = response.getOutputStream(); 
  61.             BufferedImage image = new BufferedImage(width, height, 
  62.                     BufferedImage.TYPE_INT_RGB); 
  63.             Graphics g = image.getGraphics(); 
  64.             // 设定背景色 
  65.             g.setColor(getRandColor(200, 250)); 
  66.             g.fillRect(0, 0, width, height); 
  67.  
  68.             // 设定字体 
  69.             Font mFont = new Font("Times New Roman", Font.BOLD, 18);// 设置字体 
  70.             g.setFont(mFont); 
  71.  
  72.             // 画边框 
  73.             // g.setColor(Color.BLACK); 
  74.             // g.drawRect(0, 0, width - 1, height - 1); 
  75.  
  76.             // 随机产生干扰线，使图象中的认证码不易被其它程序探测到 
  77.             g.setColor(getRandColor(160, 200)); 
  78.             // 生成随机类 
  79.             Random random = new Random(); 
  80.             for (int i = 0; i < 155; i++) { 
  81.                 int x2 = random.nextInt(width); 
  82.                 int y2 = random.nextInt(height); 
  83.                 int x3 = random.nextInt(12); 
  84.                 int y3 = random.nextInt(12); 
  85.                 g.drawLine(x2, y2, x2 + x3, y2 + y3); 
  86.             } 
  87.  
  88.             // 将认证码显示到图象中 
  89.             g.setColor(new Color(20 + random.nextInt(110), 20 + random 
  90.                     .nextInt(110), 20 + random.nextInt(110))); 
  91.  
  92.             g.drawString(s, 2, 16); 
  93.  
  94.             // 图象生效 
  95.             g.dispose(); 
  96.             // 输出图象到页面 
  97.             ImageIO.write((BufferedImage) image, "JPEG", out); 
  98.             out.close(); 
  99.         } catch (Exception e) { 
100.             e.printStackTrace(); 
101.         } 
102.         return null; 
103.     } 
104.  
105.     private Color getRandColor(int fc, int bc) { // 给定范围获得随机颜色 
106.         Random random = new Random(); 
107.         if (fc > 255) 
108.             fc = 255; 
109.         if (bc > 255) 
110.             bc = 255; 
111.         int r = fc + random.nextInt(bc - fc); 
112.         int g = fc + random.nextInt(bc - fc); 
113.         int b = fc + random.nextInt(bc - fc); 
114.         return new Color(r, g, b); 
115.     } 
116. } 
117.  
118.  
119. jsp页面的调用  
120. <html:img page="/validatecode.do" border="0" onclick="this.src='/validatecode.do'" alt="请输入此验证码，如看不清请点击刷新。" style="cursor:pointer" />