jsp验证码源码
1.<%@ pageimport="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" %>2.<%@ page import="java.io.OutputStream" %>
3.<%!
4.Color getRandColor(int fc,int bc){
5.Random random = new Random();
6.if(fc>255) fc=255;
7.if(bc>255) bc=255;
8.int r=fc+random.nextInt(bc-fc);
9.int g=fc+random.nextInt(bc-fc);
10.int b=fc+random.nextInt(bc-fc);
11.return new Color(r,g,b);
12.}
13.%>
14.<%
15.try{
16.response.setHeader("Pragma","No-cache");
17.response.setHeader("Cache-Control","no-cache");
18.response.setDateHeader("Expires", 0);
19.int width=60, height=20;
20.BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
21.OutputStream os=response.getOutputStream();
22.Graphics g = image.getGraphics();
23.Random random = new Random();
24.g.setColor(getRandColor(200,250));
25.g.fillRect(0, 0, width, height);
26.
27.g.setFont(new Font("Times New Roman",Font.PLAIN,18));
28.g.setColor(getRandColor(160,200));
29.for (int i=0;i<155;i++)
30.{
31.int x = random.nextInt(width);
32.int y = random.nextInt(height);
33.int xl = random.nextInt(12);
34.int yl = random.nextInt(12);
35.g.drawLine(x,y,x+xl,y+yl);
36.}
37.String sRand="";
38.for (int i=0;i<4;i++){
39.String rand=String.valueOf(random.nextInt(10));
40.sRand+=rand;
41.g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
42.g.drawString(rand,13*i+6,16);
43.}
44.session.setAttribute("rand",sRand);
45.g.dispose();
46.
47.ImageIO.write(image, "JPEG",os);
48.
49.//注意看以下几句的使用
50.os.flush();
51.os.close();
52.os=null;
53.response.flushBuffer();
54.out.clear();
55.out = pageContext.pushBody();
56.}
57.catch(IllegalStateException e)
58.{
59.System.out.println(e.getMessage());
60.e.printStackTrace();
61.}%>
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