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="" 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 class="denglu_font_title">欢迎登录</span>
<br />
<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 />
<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>
（方案三）
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
- package you package;
- import java.awt.*;
- import java.awt.image.*;
- import java.util.*;
- /**
- * @author from Internet
- * @last update:2006-05-23 Ychon
- *
- */
- public class Image {
- public String sRand = "";
- public String sgbRand = "";
- public 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);
- }
- public BufferedImage creatImage() {
- // 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(100, 250));
- g.fillRect(0, 0, width, height);
- //设定字体
- g.setFont(new Font("Comic Sans MS", 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 rand = request.getParameter("rand");
- //rand = rand.substring(0,rand.indexOf("."));
- 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);
- }
- // 图象生效
- g.dispose();
- return image;
- }
- public BufferedImage creatImageGB() {
- // 在内存中创建图象
- int width = 170, height = 28;
- //设置备选汉字，剔除一些不雅的汉字
- String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6"
- //备选汉字的长度
- ;
- int length = base.length();
- //创建内存图像
- BufferedImage image = new BufferedImage(width, height,
- BufferedImage.TYPE_INT_RGB);
- // 获取图形上下文
- Graphics g = image.getGraphics();
- //创建随机类的实例
- Random random = new Random();
- // 设定图像背景色(因为是做背景，所以偏淡)
- g.setColor(getRandColor(200, 250));
- g.fillRect(0, 0, width, height);
- //备选字体
- String[] fontTypes = {"\u5b8b\u4f53", "\u65b0\u5b8b\u4f53",
- "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66"};
- int fontTypesLength = fontTypes.length;
- //在图片背景上增加噪点
- g.setColor(getRandColor(160, 200));
- g.setFont(new Font("Comic Sans MS", Font.PLAIN, 14));
- for (int i = 0; i < 6; i++) {
- g.drawString("*********************************************", 0,
- 5 * (i + 2));
- }
- //取随机产生的认证码(6个汉字)
- //保存生成的汉字字符串
- for (int i = 0; i < 6; i++) {
- int start = random.nextInt(length);
- String rand = base.substring(start, start + 1);
- sgbRand += rand;
- //设置字体的颜色
- g.setColor(getRandColor(10, 150));
- //设置字体
- g.setFont(new Font(fontTypes[random.nextInt(fontTypesLength)],
- Font.BOLD, 18 + random.nextInt(6)));
- //将此汉字画到图片上
- g.drawString(rand, 24 * i + 10 + random.nextInt(8), 24);
- }
- g.dispose();
- return image;
- }
- public static void main(String[] args) {
- Image image = new Image();
- }
- }
- 输出显示：
- <%@ page import="javax.imageio.*,com.Image" %>
- <%
- Image image = new Image();
- //设置页面不缓存
- response.setHeader("Pragma","No-cache");
- response.setHeader("Cache-Control","no-cache");
- response.setDateHeader("Expires", 0);
- // 输出图象到页面
- out.clear();
- //ImageIO.write(image.creatImage(), "JPEG", response.getOutputStream()); //数字
- ImageIO.write(image.creatImageGB(), "JPEG", response.getOutputStream()); //汉字
- // 将认证码存入SESSION
- //session.setAttribute("imgCode",image.sRand); //数字
- session.setAttribute("imgCode",image.sgbRand);//汉字
- %>