JAVAWeb 使用HTML页面创建验证码

浏览数：22 / 时间：2015年06月08日

实际的项目中登录中需要用到验证码，接下来是我Web项目中所用到验证码技术

index.html

 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 2 <html>
 3   <head>
 4     <title>index.html</title>
 5     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 6     <meta http-equiv="description" content="this is my page">
 7     <meta http-equiv="content-type" content="text/html; charset=UTF-8">
 8     <!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
 9   </head>
10    <script type="text/javascript">
11    function clk_image(){
12     var img = document.getElementById("sCodeImg");   
13     img.src = "Validate.jsp?" + Math.random(); 
14 }
15    </script>
16   <body>
17    <input type="text" name="code" id="code"/>
18     <img  id="sCodeImg"  alt="请输入验证码" src="Validate.jsp?,Math.random();" onclick="return clk_image();" width="65" height="25">
19   </body>
20 </html>

View Code

Validate.jsp

 1 <%@ page contentType="text ml;charset=UTF-8" language="java"%>
 2 <%@ page import="java.awt.*"%>
 3 <%@ page import="java.awt.image.*"%>
 4 <%@ page import="java.util.*"%>
 5 <%@ page import="javax.imageio.*"%>
 6  
 7 <%!Color getRandColor(int fc, int bc) {
 8         Random random = new Random();
 9         if (fc > 255)
10             fc = 255;
11         if (bc > 255)
12             bc = 255;
13         int r = fc + random.nextInt(bc - fc);
14         int g = fc + random.nextInt(bc - fc);
15         int b = fc + random.nextInt(bc - fc);
16         return new Color(r, g, b);
17     }%>
18 <%
19     response.setHeader("Pragma", "No-cache");
20     response.setHeader("Cache-Control", "no-cache");
21     response.setDateHeader("Expires", 0);
22     int width = 60;
23     int height = 20;
24     BufferedImage image = new BufferedImage(width, height,
25             BufferedImage.TYPE_INT_RGB);
26     Graphics g = image.getGraphics();
27     Random random = new Random();
28     g.setColor(getRandColor(200, 250));
29     g.fillRect(0, 0, width, height);
30     g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
31     g.setColor(getRandColor(160, 200));
32     for (int i = 0; i < 155; i++) {
33         int x = random.nextInt(width);
34         int y = random.nextInt(height);
35         int x1 = random.nextInt(12);
36         int y1 = random.nextInt(12);
37         g.drawLine(x, y, x + x1, y + y1);
38     }
39     String sRand = "";
40     for (int i = 0; i < 4; i++) {
41         String rand = String.valueOf(random.nextInt(10));
42         sRand += rand;
43         g.setColor(new Color(20 + random.nextInt(110), 20 + random
44                 .nextInt(110), 20 + random.nextInt(110)));
45         g.drawString(rand, 13 * i + 6, 16);
46     }
47     // 将验证码保存到session中,登录验证时再取出和用户输入的进行比较
48     session.setAttribute("checkCode", sRand);
49     g.dispose();
50     ImageIO.write(image, "JPEG", response.getOutputStream());
51     out.clear();
52     out = pageContext.pushBody();
53 %>