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());}}复制代码
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*/ public class resultservlet extends httpservlet {private static final long serialversionuid = -4023881398470853660l;public void doget(httpservletrequest request,httpservletresponse response) throws servletexception,ioexception{dopost(request, response);}public void dopost(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();}}