TA的每日心情 | 开心
2021-3-12 23:18 |
|---|
签到天数: 2 天 [LV.1]初来乍到
|
|
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
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.*"%>
<%@ 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;i<4;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();
%>
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("<script>alert("验证码错误！请重试。")</script>"); out.println("<script>history.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.
源码下载：http://file.javaxxz.com/2014/10/1/005148203.zip |
|
|手机版|Java学习者论坛
( 声明：本站资料整理自互联网，用于Java学习者交流学习使用，对资料版权不负任何法律责任，若有侵权请及时联系客服屏蔽删除 )
发表于 2014-10-1 00:51:48