共有回帖数 1 个
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[前言]:图片验证在有关注册和发表留言经常用到.我在此用jsp写了个.供大家参考. 其中 com.sun.image不是java的标准包.需要另外下载.相关地址为:http://java.sun.com/products/java-media/jai/
1. random.jsp (产生四位的随机字符,由0-9,a-z,A-Z构成.并把最终字符串放到session中保存以让后续页面验证真伪)
代码如下:
%@ page autoFlush="false" import="java.util.*,java.awt.*,java.awt.image.*,
com.sun.image.codec.jpeg.*,java.util.*"%
%@ page import="" contentType="text/html; charset=gb2312"%
%
String chose=
"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
char display[]={'0',' ','0',' ','0',' ','0'},ran[]={'0','0','0','0'},temp;
Random rand=new Random();
for(int i=0;i4;i++)
{
temp=chose.charAt(rand.nextInt(chose.length()));
display[i*2]=temp;
ran=temp;
}
String random=String.valueOf(display);
session.setAttribute("random",String.valueOf(ran));
%
%
out.clear();
response.setContentType("image/jpeg");
response.addHeader("pragma","NO-cache");
response.addHeader("Cache-Control","no-cache");
response.addDateHeader("Expries",0);
int width=47, height=15;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
//以下填充背景颜色
g.setColor(Color.GREEN);
g.fillRect(0, 0, width, height);
//设置字体颜色
g.setColor(Color.RED);
g.drawString(random,3,10);
g.dispose();
ServletOutputStream outStream = response.getOutputStream();
JPEGImageEncoder encoder =JPEGCodec.createJPEGEncoder(outStream);
encoder.encode(image);
outStream.close();
%
楼主 2016-10-19 13:24 回复
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2. img.jsp (显示验证图片.由于本程序简单让验证程序也一并放在了一起)
代码如下:
%@ page contentType="text/html; charset=gb2312" language="java"%
%
String num=request.getParameter("num");
String random=(String)session.getAttribute("random");
if(num!=null&&random!=null)
{
if(!num.equals(random))
{
out.println("scriptalert('验证码错误！请重试。')/script");
out.println("scripthistory.go(-1)/script");
//response.sendRedirect("img.jsp");
}
else
{
out.println("center验证成功！/center");
}
}
%
html
head
title图片验证/title
meta http-equiv="Content-Type" content="text/html; charset=gb2312"
/head
body
form action="img.jsp" method="post"
table
tr
td
input type="text" name="num" size=10
/td
td
img src="random.jsp"
/td
/tr
/table
input type="submit" value="OK"
/form
/body
/html
说明:有兴趣的网友可以在此基础上增加图片的内容.比如让背景加上纹理.让字符位置歪斜以加大扫描程序的难度.大家有什么看法和建议,都可以回复中提出来....
1楼 2016-10-19 13:24 回复
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