JAVA验证码的实现参考

java验证码的实现(一)?

1.ImageServlet类的实现：

package com.mobile.control;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.util.Random;

import javax.imageio.ImageIO;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class ImageServlet extends HttpServlet {

?????? public void doGet(HttpServletRequest request, HttpServletResponse response)

???????????????????? throws ServletException, IOException {

????????????? this.doPost(request, response);

?????? }

?????? // 生成数字和字母的验证码

?????? public void doPost(HttpServletRequest request, HttpServletResponse response)

???????????????????? throws ServletException, IOException {

????????????? BufferedImage img = new BufferedImage(68, 22,

??????????????????????????? BufferedImage.TYPE_INT_RGB);

????????????? // 得到该图片的绘图对象

????????????? Graphics g = img.getGraphics();

????????????? Random r = new Random();

????????????? Color c = new Color(200, 150, 255);

????????????? g.setColor(c);

????????????? // 填充整个图片的颜色

????????????? g.fillRect(0, 0, 68, 22);

????????????? // 向图片中输出数字和字母

????????????? StringBuffer sb = new StringBuffer();

????????????? char[] ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();

????????????? int index, len = ch.length;

????????????? for (int i = 0; i < 4; i ++) {

???????????????????? index = r.nextInt(len);

???????????????????? g.setColor(new Color(r.nextInt(88), r.nextInt(188), r.nextInt

(255)));

???????????????????? g.setFont(new Font("Arial", Font.BOLD | Font.ITALIC, 22));// 输出的

字体和大小?????????????????

???????????????????? g.drawString("" + ch[index], (i * 15) + 3, 18);//写什么数字，在图片

的什么位置画

???????????????????? sb.append(ch[index]);

????????????? }

????????????? request.getSession().setAttribute("piccode", sb.toString());

????????????? ImageIO.write(img, "JPG", response.getOutputStream());

?????? }????

}

2.web.xml中的配置

?????? <servlet>

????????????? <servlet-name>ImageServlet</servlet-name>

????????????? <servlet-class>com.mobile.control.ImageServlet</servlet-class>

?????? </servlet>

?????? <servlet-mapping>

????????????? <servlet-name>ImageServlet</servlet-name>

????????????? <url-pattern>/servlet/ImageServlet</url-pattern>

?????? </servlet-mapping>

3.页面源程序

<%@ page contentType="text/html; charset=utf-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

?????? <head>

????????????? <title>系统登录</title>

????????????? <meta http-equiv="pragma" content="no-cache">

????????????? <meta http-equiv="cache-control" content="no-cache">

????????????? <meta http-equiv="expires" content="0">

????????????? <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

????????????? <meta http-equiv="description" content="This is my page">????????????

????????????? <link href="<%=request.getContextPath()%>/jsp/style/stylet.css"

???????????????????? rel="stylesheet" type="text/css">??

????????????? <mce:script type="text/javascript"><!--

???????????????????? // 重载验证码

???????????????????? function reloadVerifyCode(){

??????????????????????????? var timenow = new Date().getTime();???????????????????????

??????????????????????????? document.getElementById("safecode").src="<%

=request.getContextPath()%>/servlet/ImageServlet?d="+timenow;

???????????????????? }

// --></mce:script>

?????? </head>

?????? <body>

????????????? <div id="box1">

???????????????????? <div id="tab_box">

??????????????????????????? <form action="<%=request.getContextPath() %

>/servlet/LoginServlet" method="post" name="login">

?????????????????????????????????? <span class="denglu_font_title">欢迎登录</span>

?????????????????????????????????? <br />

?????????????????????????????????? <label for="userid" class="yonghuming_font">

????????????????????????????????????????? 用户：

?????????????????????????????????? </label>

?????????????????????????????????? <input name="userid" type="text" id="userid"

accesskey="n"

????????????????????????????????????????? tabindex="1"

????????????????????????????????????????? style="font-family: '宋体'; font-size: 12px;

color: #575757" />

?????????????????????????????????? <br />

?????????????????????????????????? <label for="passwd" class="yonghuming_font">

????????????????????????????????????????? 密码：

?????????????????????????????????? </label>

?????????????????????????????????? <input name="passwd" type="password" id="passwd"

tabindex="2"

????????????????????????????????????????? style="font-family: '宋体'; font-size: 12px;

color: #575757" />

?????????????????????????????????? <br />

?????????????????????????????????? <br />??????????????????????????????????????????????

?????????????????????????????????? <label for="verifyCode" class="yonghuming_font">

????????????????????????????????????????? 验证码：

?????????????????????????????????? </label>

?????????????????????????????????? <input type="text" id="verifyCode" name="verifyCode"

size="6" />

?????????????????????????????????? <img alt="验证码" id="safecode" src="<%

=request.getContextPath()%>/servlet/ImageServlet">

?????????????????????????????????? <a href="javascript:reloadVerifyCode();"

mce_href="javascript:reloadVerifyCode();">看不清楚</a>

?????????????????????????????????? <input name="denglu_tijiao" type="submit"

id="denglu_tijiao"

????????????????????????????????????????? tabindex="3" value="确认" />

?????????????????????????????????? <input name="denglu_chongzi" type="reset"

id="denglu_reset"

????????????????????????????????????????? tabindex="4" value="重置" />

?????????????????????????????????? <input type="hidden" name="flag" value="logon">

??????????????????????????? </form>

??????????????????????????? <font color='red'></font>

???????????????????? </div>

????????????? </div>

?????? </body>

</html>

JAVA验证码的兑现参考

java验证码的实现(一)?