Java开发网 - JSP彩色验证码

Topic: JSP彩色验证码

1.JSP彩色验证码

Posted by: chengbd
Posted on: 2004-07-06 15:21

生成有4个随机数字和杂乱背景的图片，数字和背景颜色会改变，服务器端刷新（用history.go(-1)也会变）
原型参考ALIBABA http://china.alibaba.com/member/showimage

------------产生验证码图片的文件-----image.jsp-------------------------------------------

<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" %>
<%!
Color getRandColor(int fc,int bc){//给定范围获得随机颜色
Random random = new Random();
if(fc>255) fc=255;
if(bc>255) bc=255;
int r=fc+random.nextInt(bc-fc);
int g=fc+random.nextInt(bc-fc);
int b=fc+random.nextInt(bc-fc);
return new Color(r,g,b);
}
%>
<%
//设置页面不缓存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);

// 在内存中创建图象
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

// 获取图形上下文
Graphics g = image.getGraphics();

//生成随机类
Random random = new Random();

// 设定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);

//设定字体
g.setFont(new Font("Times New Roman",Font.PLAIN,18));

//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);

// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160,200));
for (int i=0;i<155;i++)
{
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x,y,x+xl,y+yl);
}

// 取随机产生的认证码(4位数字)
String sRand="";
for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;
// 将认证码显示到图象中
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
g.drawString(rand,13*i+6,16);
}

// 将认证码存入SESSION
session.setAttribute("rand",sRand);

// 图象生效
g.dispose();

// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());

%>

---------------使用验证码图片的文件---------a.jsp------------------------------------

<%@ page contentType="text/html;charset=gb2312" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>认证码输入页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>
<body>
<form method=post action="check.jsp">
<table>
<tr>
<td align=left>系统产生的认证码：</td>
<td><img border=0 src="image.jsp"></td>
</tr>
<tr>
<td align=left>输入上面的认证码：</td>
<td><input type=text name=rand maxlength=4 value=""></td>
</tr>
<tr>
<td colspan=2 align=center><input type=submit value="提交检测"></td>
</tr>
</form>
</body>
</html>

-----------------验证的页面----------check.jsp

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<html>
<head>
<title>认证码验证页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>

<body>
<%
String rand = (String)session.getAttribute("rand");
String input = request.getParameter("rand");
%>
系统产生的认证码为： <%= rand %><br>
您输入的认证码为： <%= input %><br>
<br>
<%
if (rand.equals(input)) {
%>
<font color=green>输入相同，认证成功！</font>
<%
} else {
%>
<font color=red>输入不同，认证失败！</font>
<%
}
%>
</body>
</html>
代码：

jspcode.rar (2.22k)

2.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: why Posted on: 2004-07-07 04:35 请问大侠这是原创的吗？

3.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: chengbd Posted on: 2004-07-07 10:17 不是原创，以前收集的，记不起出处了，感觉功能不错。能不能加一分呀：)

4.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: why Posted on: 2004-07-07 11:19 这样子不够加一分尤其是我不太喜欢它直接用 JSP 不过我会看看纪录，大侠好像在J2EE版上还有一两个不错但未足以加分的贴子或者可以集腋成裘的算请耐心等候一下

5.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: chengbd Posted on: 2004-07-07 12:24 用JSP显示还是相当方便的嘛! 只是想凑够5个积分，就可以看看其它看不到的帖子了。在这里向版主要分，真是惭愧呀!

6.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: realpal Posted on: 2004-07-15 20:45 不行啊，我在weblogic812下验证通不过啊，验证码图片始终出不来。请问是怎么回事？没有错误，就是页面图片显示不出来。谢谢！

7.Re:JSP彩色验证码 [Re: realpal]

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Posted by: realpal
Posted on: 2004-07-16 14:55

修改了一下，在win下没问题，但是在rh linux下有问题。可能是linux的图像支持不好。请问有没有什么解决办法？谢谢
错误代码为：
Error 500--Internal Server Error
java.lang.NoClassDefFoundError
  at java.lang.Class.forName0(Native Method)
  at java.lang.Class.forName(Class.java:140)
  at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
  at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1041)
  at java.awt.image.BufferedImage.getGraphics(BufferedImage.java:1031)
  at com.aspire.misc.infrastruct.image.doGet(image.java:51)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
  at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:971)
  at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:402)
  at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
  at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6350)
  at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
  at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
  at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3635)
  at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2585)
  at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
  at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)

Error 500--Internal Server Error
java.lang.NoClassDefFoundError
  at java.lang.Class.forName0(Native Method)
  at java.lang.Class.forName(Class.java:140)
  at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
  at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1041)
  at java.awt.image.BufferedImage.getGraphics(BufferedImage.java:1031)
  at com.aspire.misc.infrastruct.image.doGet(image.java:51)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
  at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:971)
  at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:402)
  at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
  at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6350)
  at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
  at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
  at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3635)
  at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2585)
  at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
  at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)

8.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: kkg Posted on: 2004-07-25 14:23 测试感觉很好~

9.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: hohaischooldays Posted on: 2004-07-31 21:00 请教: //设置页面不缓存的好处是什么?

10.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: 周轻舟 Posted on: 2004-08-26 16:57 我的也是这样，在linux下无法显示，到底是什么原因呢？

11.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: freshlll Posted on: 2004-09-09 13:13 缓存就会写磁盘吗！这必然会耗时间

12.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: lnsylt Posted on: 2004-09-09 17:06 关注！

13.Re:JSP彩色验证码 [Re: chengbd]	Copy to clipboard
Posted by: fanxingabc16 Posted on: 2004-09-15 11:44 我看还是在倒数第二行加上个 response.reset(); 比较保险