实现主要包含两个类，一个是生成验证码，一个是判断验证码输入是否正确 实现原理比较简单，将汉字和干扰线生成图片并将汉字保存到session，前台获取每次生成的验证码图片进行展示，验证的时候就获取文本框输入的值传到后台与session值进行比较，功能就怎么简单。一、生成汉字验证码的类package com.veryCode;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;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;/** * 生成随机汉字验证码 * @author feizi * @time 2015-1-30下午3:16:55 */public class DrawVeryCode extends HttpServlet {private static final long serialVersionUID = -3002087466925846353L;public static final int WIDTH = 120;public static final int HEIGHT = 30;public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{this.doPost(request, response);}public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{request.setCharacterEncoding(“utf-8”);response.setContentType(“text/html;charset=utf-8”);//创建图片缓存BufferedImage bi = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);//获得画布Graphics g = bi.getGraphics();//设置背景颜色setBackGroundColor(g);//设置边框setBorder(g);//绘制干扰线drawRandomLine(g);//产生随机汉字验证码String randomChar = drawRandomChar((Graphics2D)g);//强制转换//将产生的随机汉字验证码存进session中进行保存request.getSession().setAttribute(“veryCode”, randomChar);//设置响应信息的类型为图片类型response.setContentType(“image/jpeg”);//控制Http缓存，设置响应头信息，防止浏览器缓存response.setDateHeader(“expries”, -1);response.setHeader(“Cache-Control”, “no-Cache”);response.setHeader(“Pargma”, “no-Cache”);//将验证码图片写到浏览器中ImageIO.write(bi, “jpg”, response.getOutputStream());}/*** 设置背景颜色* @param g*/private void setBackGroundColor(Graphics g){//设置背景颜色g.setColor(Color.WHITE);//填充区域g.fillRect(0, 0, WIDTH, HEIGHT);}/*** 设置边框* @param g*/private void setBorder(Graphics g){//设置边框颜色g.setColor(Color.BLUE);//设置边框区域g.drawRect(1, 1, WIDTH – 2, HEIGHT – 2);}/*** 画干扰线* @param g*/private void drawRandomLine(Graphics g){//设置干扰线的颜色g.setColor(Color.GREEN);//设置线条条数并开始画线for (int i = 0; i < 40; i++) {int x1 = new Random().nextInt(WIDTH);int y1 = new Random().nextInt(HEIGHT);int x2 = new Random().nextInt(WIDTH);int y2 = new Random().nextInt(HEIGHT);//开始画线g.drawLine(x1, y1, x2, y2);}}/*** 画随机汉字* @param g*/private String drawRandomChar(Graphics2D g){StringBuffer sb = new StringBuffer();//设置颜色g.setColor(Color.RED);//设置字体g.setFont(new Font(“宋体”, Font.BOLD, 20));//准备常用汉字集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″;int x = 5;//控制字数,最多4个字for (int i = 0; i < 4; i++) {//设置字体旋转角度int degree = new Random().nextInt() % 30;//截取汉字String ch = base.charAt(new Random().nextInt(base.length())) + “”;//追加到sb中sb.append(ch);//顺时针旋转g.rotate(degree * Math.PI / 180, x, 20);//开始画汉字g.drawString(ch, x, 20);//逆时针旋转g.rotate(-(degree * Math.PI / 180), x, 20);x += 30;}return sb.toString();}public static void main(String[] args) {String s = “1234565236985”;System.out.println(s.charAt(5) + “”);System.out.println(new Random().nextInt());}}二、验证前台页面上输入的验证码信息package com.veryCode;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;/** * 验证页面上输入的验证码信息 * @author feizi * @time 2015-2-2上午8:14:22 */{serialVersionUID = -4023881398470853660L;(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{doPost(request, response);}(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{request.setCharacterEncoding(“utf-8”);response.setContentType(“text/html;charset=utf-8”);//产生的正确的验证码值String validateC = (String) request.getSession().getAttribute(“veryCode”);//浏览器中用户输入的验证码值String veryCode = request.getParameter(“code”);PrintWriter out = response.getWriter();if(null == veryCode || “”.equals(veryCode)){out.println(“请输入验证码…”);}else{if(validateC.equals(veryCode)){out.print(1);}else{out.println(“对不起，验证码输入错误…”);}}out.flush();out.close();}} 三，，编写前台页面，展示验证码信息=><%String path = request.getContextPath();String basePath = request.getScheme()+”://”+request.getServerName()+”:”+request.getServerPort()+path+”/”;%>>>随机汉字验证码======>=> >=====>==”DrawVeryCode”> =>==> </body></html>四，js文件/** * 点击切换一张验证码 */function changeImg(){var imgSrc = $(‘#imgObj’);var src = imgSrc.attr(‘src’);// alert(“src:”+src);imgSrc.attr(‘src’,chgUrl(src));$(‘#info’).html(”);}//时间戳处理/** * 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(url){var timestamp = (new Date()).valueOf();url = url.substring(0,12);//alert(“timestamp:”+timestamp+”>>>>url:”+url);if(url.indexOf(“&”) >= 0){url = url + “×tamp=” + timestamp;}else{url = url + “?timestamp=” + timestamp;}return url;}/** * 验证输入的验证码 */function isRightCode(){var code = $(‘#veryCode’).val();code = “code=” + code;$.ajax({type:”POST”,url:”ResultServlet”,dataType:”text”,data:code,success:function(data){//验证以后处理提交信息或错误信息if(data == 1){$(“#info”).html(“恭喜您，成功了！”);return;}else{$(“#info”).html(data);return;}},error:function(){alert(‘链接出现错误！’);}});}五，运行效果
ok，到这里基本上全部已经好了，如果想实现更加复杂一点的可以再自行进行研究扩展。。。
源码我已经上传至csdn,有需要的话可以去下载。
别人失去了信心，他却下决心实现自己的目标。
