jsp验证码

以前是用servlet写现在不清楚
Google吧

img标签的url里面指向servlet setvlet响应产生随机字符串然后制图然后返回一个文件流

jCaptcha 和 patchca :jCaptcha: http://jcaptcha.sourceforge.net/ patchca: http://code.google.com/p/patchca/

我这里有以前项目里用过的，与大家分享一下：
文件上传处理页面：
<body>
<%
// 新建一个SmartUpload对象
SmartUpload su = new SmartUpload();
// 上传初始化
su.initialize(pageContext);
// 设定上传限制
// 1.限制每个上传文件的最大长度。
// su.setMaxFileSize(10000);
// 2.限制总上传数据的长度。
// su.setTotalMaxFileSize(20000);
// 3.设定允许上传的文件（通过扩展名限制）,仅允许doc,txt文件。
// su.setAllowedFilesList("doc,txt");
// 4.设定禁止上传的文件（通过扩展名限制）,禁止上传带有exe,bat,
jsp,htm,html扩展名的文件和没有扩展名的文件。
// su.setDeniedFilesList("exe,bat,jsp,htm,html,,");
// 上传文件
su.upload();
// 将上传文件全部保存到指定目录
int count = su.save("/upload");
out.println(count+"个文件上传成功！<br>");// 利用Request对象获取参数之值
out.println("TEST="+su.getRequest().getParameter("TEST")
+"<BR><BR>");// 逐一提取上传文件信息，同时可保存文件。
for (int i=0;i<su.getFiles().getCount();i++)
{
com.jspsmart.upload.File file = su.getFiles().getFile(i);// 若文件不存在则继续
if (file.isMissing()) continue;// 显示当前文件信息
out.println("<TABLE BORDER=1>");
out.println("<TR><TD>表单项名（FieldName）</TD><TD>"
+ file.getFieldName() + "</TD></TR>");
out.println("<TR><TD>文件长度（Size）</TD><TD>" +
file.getSize() + "</TD></TR>");
out.println("<TR><TD>文件名（FileName）</TD><TD>"
+ file.getFileName() + "</TD></TR>");
out.println("<TR><TD>文件扩展名（FileExt）</TD><TD>"
+ file.getFileExt() + "</TD></TR>");
out.println("<TR><TD>文件全名（FilePathName）</TD><TD>"
+ file.getFilePathName() + "</TD></TR>");
out.println("</TABLE><BR>");// 将文件另存
// file.saveAs("/upload/" + myFile.getFileName());
// 另存到以WEB应用程序的根目录为文件根目录的目录下
// file.saveAs("/upload/" + myFile.getFileName(),
su.SAVE_VIRTUAL);
// 另存到操作系统的根目录为文件根目录的目录下
// file.saveAs("c:\\temp\\" + myFile.getFileName(),
su.SAVE_PHYSICAL);}
%>
</body>
提交页面：
<%
request.setCharacterEncoding("utf-8");
     //获取Session会话中缓存的验证码
String rand = (String)session.getAttribute("rand");
if(rand==null){
   System.out.print("问题出现");
}
     //获取用户输入的验证码
     String input = request.getParameter("input");

   if (rand.equals(input)) {
      out.println("验证成功！！");
}else{
       out.println("验证失败！！");
}
%>
显示页面：doTest。jsp
<html>
<head>
<title>登录页面</title>
   <script language="javascript">
          /*在文字上使验证码刷新 */
   function reloadImage(url){
      var img = document.getElementById("img");
      img.src = url+"?" + Math.random();
   }
   </script>
</head>
<body>
<form id="dForm" method="post" action="doTest.jsp">
            验证码:
            <input type="text" name="input" size="12" >
<img id="img" border=0 src="code.jsp" />
<a href="javaScript:reloadImage('code.jsp');">看不清</a>
<input type="button" value="看不清"
onclick="javascript:document.getElementById('img').src='code.jsp?'+Math.random()">

<br/>
<input type="submit" value="验证测试">
</form> </body>
</html>

大致步骤：首先创建了一个内存图像的实例对象，再得到此内存图像的图形上下文对象，接着再用这个上下文对象画背景、边框。接下来，随机生成4个在mapTable[]数组中的字符，组成字符串作为验证字符串，并输出在内存中，为了造成一定的干扰，随机画了10个干扰点，如果要加大干扰效果，可再多画一些点。
把生成的验证码session对象保存，在接收登录处理页面，对用户输入的验证码和这个session对象中保存的字符串作比较，如果相同则表示验证通过。

嗯 patchca 很好用的，又小巧，功能又多，我原来用 patchca 做的：

patchca的例子的源码:
package org.patchca.demo;import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Panel;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;import org.patchca.color.SingleColorFactory;
import org.patchca.filter.predefined.CurvesRippleFilterFactory;
import org.patchca.filter.predefined.DiffuseRippleFilterFactory;
import org.patchca.filter.predefined.DoubleRippleFilterFactory;
import org.patchca.filter.predefined.MarbleRippleFilterFactory;
import org.patchca.filter.predefined.WobbleRippleFilterFactory;
import org.patchca.service.ConfigurableCaptchaService;public class PatchcaFilterDemo extends Frame implements ActionListener { private static final long serialVersionUID = 6698906953413370733L;
private BufferedImage img;
private Button reloadButton;
private int counter; public PatchcaFilterDemo() {
super("Patchca demo");
setSize(200, 140);
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    int x = (dim.width-this.getSize().width)/2;
    int y = (dim.height-this.getSize().height)/2;
    setLocation(x, y);
Panel bottom = new Panel();
reloadButton = new Button("Next filter");
reloadButton.addActionListener(this);
bottom.add(reloadButton);
add(BorderLayout.SOUTH, bottom);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
dispose();
}
});
} public void update(Graphics g) {
paint(g);
} public void paint(Graphics g) {
if (img == null) {
createImage();
}
if (img != null) {
g.drawImage(img, 20, 30, this);
}
} public void createImage() {
ConfigurableCaptchaService cs = new ConfigurableCaptchaService();
cs.setColorFactory(new SingleColorFactory(new Color(25, 60, 170)));
switch (counter % 5) {
case 0:
cs.setFilterFactory(new CurvesRippleFilterFactory(cs.getColorFactory()));
break;
case 1:
cs.setFilterFactory(new MarbleRippleFilterFactory());
break;
case 2:
cs.setFilterFactory(new DoubleRippleFilterFactory());
break;
case 3:
cs.setFilterFactory(new WobbleRippleFilterFactory());
break;
case 4:
cs.setFilterFactory(new DiffuseRippleFilterFactory());
break;
}
img = cs.getCaptcha().getImage();
counter++;
} @Override
public void actionPerformed(ActionEvent evt) {
if (evt.getSource() == reloadButton) {
createImage();
repaint();
} } public static void main(String[] args) {
PatchcaFilterDemo f = new PatchcaFilterDemo();
f.setVisible(true);
}}

写了个使用patchca生成验证码，然后进行验证的例子，可以参考一下：http://www.cppblog.com/biao/archive/2010/12/28/137589.html

jsp servlet都可以jsp还不用配xml网上搜搜一大堆

image.jsp<%@ page contentType="image/jpeg" import="java.awt.*,
java.awt.image.*,java.util.*,javax.imageio.*" %>
<%!
Color getRandColor(int fc,int bc)
{
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);
}
%>
<%
out.clear();//这句针对resin服务器，如果是tomacat可以不要这句
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
Random random = new Random();
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman",Font.PLAIN,18));
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);
}
String sRand="";
for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
g.drawString(rand,13*i+6,16);
}
// 将认证码存入SESSION
session.setAttribute("rand",sRand);
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
%>

login.jsp<%@ page contentType="text/html;charset=gbk" %>
<%@ page language="java" import="java.sql.*" errorPage="" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>用户登录</title>
<script language="javascript">
function loadimage(){
document.getElementById("randImage").src = "image.jsp?"+Math.random();
}
</script>
</head>
<body>
<table width="256" border="0" cellpadding="0" cellspacing="0">

<form action="validate.jsp" method="post" name="loginForm">
<tr>
<td width="118" height="22" valign="middle" align="center"><input type="text" name="rand" size="15"></td>
<td width="138" valign="middle" align="center"><img alt="code..." name="randImage" id="randImage" src="image.jsp" width="60" height="20" border="1" align="absmiddle"></td>
</tr>
<tr>
<td height="36" colspan="2" align="center" valign="middle"><a href="javascript:loadimage();"><font class=pt95>看不清点我</font></a></td>
</tr>
<tr>
<td height="36" colspan="2" align="center" valign="middle"><input type="submit" name="login" value="提交"></td>
</tr>
</form>
</table>
</body>
</html>

解决方案 »