JAVA 验证码解决方案汇总
(方案一)
import java.awt.Color;??
import java.awt.Font;??
import java.awt.Graphics2D;??
import java.awt.image.BufferedImage;??
import java.util.Random;??
?
import javax.imageio.ImageIO;??
import javax.servlet.ServletException;??
import javax.servlet.ServletOutputStream;??
import javax.servlet.http.HttpServlet;??
import javax.servlet.http.HttpServletRequest;??
import javax.servlet.http.HttpServletResponse;??
import javax.servlet.http.HttpSession;??
?
/**
* Package name : com.skcc.sample.action
* File name : VerifyCodeServlet.java
* Author : Administrator
* Date : 2008-9-4
* Description : VerifyCodeServlet
*/
public class VerifyCodeServlet extends HttpServlet {??
?
???
??? /**
??? * 验证码图片的宽度。
??? */
??? private int width = 60;??
???
??? /**
??? *? 验证码图片的高度。
??? */
??? private int height = 20;??
?
?
??? /**
??? * 验证码字符个数
??? */
??? private int codeCount = 4;??
?
??? /**
??? * xx
??? */
??? private int xx = 0;??
?
??? /**
??? * 字体高度??
??? */
??? private int fontHeight;??
?
??? /**
??? * codeY
??? */
??? private int codeY;??
?
??? /**
??? * codeSequence
??? */
??? char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',??
??????????? 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',??
??????????? 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };??
?
??? /**?
???? * 初始化验证图片属性?
???? */?
??? public void init() throws ServletException {??
??????? // 从web.xml中获取初始信息??
??????? // 宽度??
??????? String strWidth = this.getInitParameter("width");??
??????? // 高度??
??????? String strHeight = this.getInitParameter("height");??
??????? // 字符个数??
??????? String strCodeCount = this.getInitParameter("codeCount");??
?
??????? // 将配置的信息转换成数值??
??????? try {??
??????????? if (strWidth != null && strWidth.length() != 0) {??
??????????????? width = Integer.parseInt(strWidth);??
??????????? }??
??????????? if (strHeight != null && strHeight.length() != 0) {??
??????????????? height = Integer.parseInt(strHeight);??
??????????? }??
??????????? if (strCodeCount != null && strCodeCount.length() != 0) {??
??????????????? codeCount = Integer.parseInt(strCodeCount);??
??????????? }??
??????? } catch (NumberFormatException e) {
??????? ?e.printStackTrace();
??????? }??
?
??????? xx = width / (codeCount + 1);??
??????? fontHeight = height - 2;??
??????? codeY = height - 4;??
?
??? }??
?
??? /**
??? * @param req
??? * @param resp
??? * @throws ServletException
??? * @throws java.io.IOException
??? */
??? protected void service(HttpServletRequest req, HttpServletResponse resp)??
??????????? throws ServletException, java.io.IOException {??
?
??????? // 定义图像buffer??
??????? BufferedImage buffImg = new BufferedImage(width, height,??
??????????????? BufferedImage.TYPE_INT_RGB);??
??????? Graphics2D gd = buffImg.createGraphics();??
?
??????? // 创建一个随机数生成器类??
??????? Random random = new Random();??
?
??????? // 将图像填充为白色??
??????? gd.setColor(Color.WHITE);??
??????? gd.fillRect(0, 0, width, height);??
?
??????? // 创建字体,字体的大小应该根据图片的高度来定。??
??????? Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);??
??????? // 设置字体。??
??????? gd.setFont(font);??
?
??????? // 画边框。??
??????? gd.setColor(Color.BLACK);??
??????? gd.drawRect(0, 0, width - 1, height - 1);??
?
??????? // 随机产生160条干扰线,使图象中的认证码不易被其它程序探测到。??
??????? gd.setColor(Color.BLACK);??
??????? for (int i = 0; i < 160; i++) {??
??????????? int x = random.nextInt(width);??
??????????? int y = random.nextInt(height);??
??????????? int xl = random.nextInt(12);??
??????????? int yl = random.nextInt(12);??
??????????? gd.drawLine(x, y, x + xl, y + yl);??
??????? }??
?
??????? // randomCode用于保存随机产生的验证码,以便用户登录后进行验证。??
??????? StringBuffer randomCode = new StringBuffer();??
??????? int red = 0, green = 0, blue = 0;??
?
??????? // 随机产生codeCount数字的验证码。??
??????? for (int i = 0; i < codeCount; i++) {??
??????????? // 得到随机产生的验证码数字。??
??????????? String strRand = String.valueOf(codeSequence[random.nextInt(36)]);??
??????????? // 产生随机的颜色分量来构造颜色值,这样输出的每位数字的颜色值都将不同。??
??????????? red = random.nextInt(255);??
??????????? green = random.nextInt(255);??
??????????? blue = random.nextInt(255);??
?
??????????? // 用随机产生的颜色将验证码绘制到图像中。??
??????????? gd.setColor(new Color(red, green, blue));??
??????????? gd.drawString(strRand, (i + 1) * xx, codeY);??
?
??????????? // 将产生的四个随机数组合在一起。??
??????????? randomCode.append(strRand);??
??????? }??
??????? // 将四位数字的验证码保存到Session中。??
??????? HttpSession session = req.getSession();??
??????? session.setAttribute("validateCode", randomCode.toString());??
?
??????? // 禁止图像缓存。??
??????? resp.setHeader("Pragma", "no-cache");??
??????? resp.setHeader("Cache-Control", "no-cache");??
??????? resp.setDateHeader("Expires", 0);??
?
??????? resp.setContentType("image/jpeg");??
?
??????? // 将图像输出到Servlet输出流中。??
??????? ServletOutputStream sos = resp.getOutputStream();??
??????? ImageIO.write(buffImg, "jpeg", sos);??
??????? sos.close();??
??? }??
?
}?
产生结果servlet
import java.io.IOException;??
import java.io.PrintWriter;??
?
import javax.servlet.ServletException;??
import javax.servlet.http.HttpServlet;??
import javax.servlet.http.HttpServletRequest;??
import javax.servlet.http.HttpServletResponse;??
?
/**
* Package name : com.skcc.sample.action
* File name : ResultServlet.java
* Author : Administrator
* Date : 2008-9-4
* Description : ResultServlet
*/
public class ResultServlet extends HttpServlet {??
?
??? /**?
???? * The doGet method of the servlet. <br>?
???? *?
???? * This method is called when a form has its tag value method equals to get.?
???? *??
???? * @param request the request send by the client to the server?
???? * @param response the response send by the server to the client?
???? * @throws ServletException if an error occurred?
???? * @throws IOException if an error occurred?
???? */?
??? public void doGet(HttpServletRequest request, HttpServletResponse response)??
??????????? throws ServletException, IOException {??
?
??????? doPost(request, response);??
??? }??
?
??? /**?
???? * The doPost method of the servlet. <br>?
???? *?
???? * This method is called when a form has its tag value method equals to post.?
???? *??
???? * @param request the request send by the client to the server?
???? * @param response the response send by the server to the client?
???? * @throws ServletException if an error occurred?
???? * @throws IOException if an error occurred?
???? */?
??? public void doPost(HttpServletRequest request, HttpServletResponse response)??
??????????? throws ServletException, IOException {??
?
??????? response.setContentType("text/html;charset=utf-8");??
??????? String validateC = (String) request.getSession().getAttribute("validateCode");??
??????? String veryCode = request.getParameter("c");??
??????? PrintWriter out = response.getWriter();??
??????? if(veryCode==null||"".equals(veryCode)){??
??????????? out.println("验证码为空");??
??????? }else{??
??????????? if(validateC.equals(veryCode)){??
??????????????? out.println("验证码正确");??
??????????? }else{??
??????????????? out.println("验证码错误");??
??????????? }??
??????? }??
??????? out.flush();??
??????? out.close();??
??? }??
?
}?
js 文件
function changeImg(){??
??? var imgSrc = $("#imgObj");??
??? var src = imgSrc.attr("src");??
??? imgSrc.attr("src",chgurl(/blog/src));??
}??
//时间戳??
//为了使每次生成图片不一致,即不让浏览器读缓存,所以需要加上时间戳??
function chgurl(/blog/url){??
??? var timestamp = (new Date()).valueOf();??
??? url = url.substring(0,17);??
??? if((url.indexOf("&")>=0)){??
??????? url = url + "×tamp=" + timestamp;??
??? }else{??
??????? url = url + "?timestamp=" + timestamp;??
??? }??
??? return url;??
}??
?
function isRightCode(){??
??? var code = $("#veryCode").attr("value");??
??? code = "c=" + code;??
??? $.ajax({??
??????? type:"POST",??
??????? url:"resultServlet",??
??????? data:code,??
??????? success:callback??
??? });??
}??
?
function callback(data){??
??? $("#info").html(data);??
}?
页面 verifyCode.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"?
??? pageEncoding="UTF-8"%>?
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">?
<html>?
??? <head>?
??????? <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">?
??????? <script type="text/javascript" src="/blog/js/verifyCode.js"></script>?
??????? <script type="text/javascript" src="/blog/js/jquery.js"></script>?
??????? <title>test verify code</title>?
??? </head>?
??? <body>?
??????? <input id="veryCode" name="veryCode" type="text"/>?
??????? <img id="imgObj" alt="JAVA 验证码解决方案集锦" src="/blog/verifyCodeServlet"/>?
??????? <a href="#" onclick="changeImg()">换一张</a>?
??????? <input type="button" value="验证" onclick="isRightCode()"/>?
??????? <div id="info"></div>?
??? </body>?
</html>
最后记得配好web.xml
?<servlet>
???? <servlet-name>VerifyCodeServlet</servlet-name>
???? <servlet-class>com.sample.action.VerifyCodeServlet</servlet-class>
??? </servlet>
??? <servlet>
???? <servlet-name>ResultServlet</servlet-name>
???? <servlet-class>com.sample.action.ResultServlet</servlet-class>
??? </servlet>
??? <servlet-mapping>
???? <servlet-name>VerifyCodeServlet</servlet-name>
???? <url-pattern>/verifyCodeServlet</url-pattern>
??? </servlet-mapping>
??? <servlet-mapping>
???? <servlet-name>ResultServlet</servlet-name>
???? <url-pattern>/resultServlet</url-pattern>
??? </servlet-mapping>
?
?
(方案二)
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 type="text" id="userid"
accesskey="n"
????????????????????????????????????????? tabindex="1"
????????????????????????????????????????? style="font-family: '宋体'; font-size: 12px;
color: #575757" />
?????????????????????????????????? <br />
?????????????????????????????????? <br />
?????????????????????????????????? <label for="passwd" type="password" id="passwd"
tabindex="2"
????????????????????????????????????????? style="font-family: '宋体'; font-size: 12px;
color: #575757" />
?????????????????????????????????? <br />
?????????????????????????????????? <br />??????????????????????????????????????????????
?????????????????????????????????? <label for="verifyCode" id="verifyCode" name="verifyCode"
size="6" />
?????????????????????????????????? <img alt="JAVA 验证码解决方案集锦" 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>
?
(方案三)
JAVA验证码带中文
该类包含数字验证码和中文汉字验证码
creatImage() 方法为数字验证码,效果:
creatImageGB() 方法为汉字验证码,效果:
Image.java 源代码
?
?
?
?
?