例如 web上的注册验证码   思路和需要用到的类麻烦讲述一下   如果有注释源码  贴上来看看吧?

1. <%@ page contentType="image/JPEG"
   
2. import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
   
3. pageEncoding="GBK"%><%!Color getRandColor(int fc, int bc) {
   
4. Random random = new Random();
   
5. if (fc > 255)
   
6. fc = 255;
   
7. if (bc > 255)
   
8. bc = 255;
   
9. int r = fc + random.nextInt(bc - fc);
   
10. int g = fc + random.nextInt(bc - fc);
    
11. int b = fc + random.nextInt(bc - fc);
    
12. return new Color(r, g, b);
    
13. }%><%
    
14. 
    
15. response.setHeader("Pragma", "No-cache");
    
16. response.setHeader("Cache-Control", "no-cache");
    
17. response.setDateHeader("Expires", 0);
    
18. 
    
19. int width = 60, height = 20;
    
20. BufferedImage image = new BufferedImage(width, height,
    
21. BufferedImage.TYPE_INT_RGB);
    
22. 
    
23. Graphics g = image.getGraphics();
    
24. 
    
25. Random random = new Random();
    
26. 
    
27. g.setColor(getRandColor(200, 250));
    
28. g.fillRect(0, 0, width, height);
    
29. 
    
30. g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
    
31. 
    
32. g.setColor(getRandColor(160, 200));
    
33. for (int i = 0; i < 100; i++) {
    
34. int x = random.nextInt(width);
    
35. int y = random.nextInt(height);
    
36. int xl = random.nextInt(12);
    
37. int yl = random.nextInt(12);
    
38. g.drawLine(x, y, x + xl, y + yl);
    
39. }
    
40. 
    
41. String sRand = "";
    
42. for (int i = 0; i < 4; i++) {
    
43. String rand = String.valueOf(random.nextInt(10));
    
44. sRand += rand;
    
45. 
    
46. g.setColor(new Color(20 + random.nextInt(110), 20 + random
    
47. .nextInt(110), 20 + random.nextInt(110)));
    
48. g.drawString(rand, 13 * i + 6, 16);
    
49. }
    
50. 
    
51. session.setAttribute("code", sRand);
    
52. 
    
53. g.dispose();
    
54. 
    
55. ImageIO.write(image, "JPEG", response.getOutputStream());
    
56. %>
    
57. 
    
58. 在你需要引入的地方：
    
59. <img border=0 src="image.jsp">
    
60. 
    
61. 就可以了。。。

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ValidateCode.rar (6.93 KB, 下载次数: 5)

2013-5-1 15:01 上传

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