@WebServlet(name = "yzmServlet")public class yzmServlet extends HttpServlet { ???private static final int WIDTH = 100; ???private static final int HEIGHT = 40; ???protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ????????doGet(request,response); ???} ???protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ???????response.setCharacterEncoding("utf-8"); ???????response.setContentType("text/html;charset=utf-8"); ???????request.setCharacterEncoding("utf-8"); ???????BufferedImage image=new BufferedImage(WIDTH,HEIGHT, BufferedImage.TYPE_INT_RGB); ???????Graphics g=image.getGraphics(); ???????//设置背景色 ???????g.setColor(Color.CYAN); ???????//填充背景色 ???????g.fillRect(0,0,WIDTH,HEIGHT); ???????//设置前景色 ???????g.setColor(Color.BLACK); ???????//设置字体 ???????Font font=new Font("仿宋",Font.BOLD,20); ???????g.setFont(font); ???????//获取验证码 ???????int len=4; ???????String result=""; ???????for(int x=0;x<len;x++){ ???????????char c=(char) RandomUtils.nextInt(65,91); ???????????result=result+c; ???????} ???????g.drawString(result,20,20); ???????//设置干扰线条 ???????for(int i=0;i<10;i++){ ???????????int x1= RandomUtils.nextInt(0,WIDTH); ???????????int x2= RandomUtils.nextInt(0,WIDTH); ???????????int y1= RandomUtils.nextInt(0,HEIGHT); ???????????int y2= RandomUtils.nextInt(0,HEIGHT); ???????????Color color=new Color(RandomUtils.nextInt(0,255),RandomUtils.nextInt(0,255),RandomUtils.nextInt(0,255)); ???????????g.setColor(color); ???????????//设置线条 ???????????g.drawLine(x1,y1,x2,y2); ???????} ???????//将获取到的验证码存储到Session中 ???????HttpSession session=request.getSession(); ???????session.setAttribute("identifyCode",result); ???????//输出图片 ???????BufferedOutputStream bos=new BufferedOutputStream(response.getOutputStream()); ???????ImageIO.write(image,"jpg",bos); ???????//ImageIO.write(image,"jpg",new File("e:\\b.jpg")); ???????bos.flush(); ???????bos.close(); ???}}

Servlet对登录界面输入的昵称/密码/验证码进行验证:

@WebServlet(name = "identifyYzmServlet")public class identifyYzmServlet extends HttpServlet { ???protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ????????doGet(request,response); ???} ???protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ????????response.setCharacterEncoding("utf-8"); ????????response.setContentType("text/html;charset=utf-8"); ????????request.setCharacterEncoding("utf-8"); ????????//获取输入的用户名 ????????String username=request.getParameter("username"); ???????//获取输入的密码 ????????String password=request.getParameter("password"); ????????//获取输入的验证码 ????????String yzm2=request.getParameter("yzm01"); ????????//获取Session对象中存取的数据 ????????HttpSession session1=request.getSession(); ????????String yzm1=(String)session1.getAttribute("identifyCode"); ????????if(!username.equals("")&&!password.equals("")&&!yzm2.equals("")){ ????????????if(username.equals("Bighead")) { ????????????????if (password.equals("4214963")) { ????????????????????if (yzm1.equals(yzm2)) { ????????????????????????response.getWriter().println("登录成功"); ????????????????????????//登录成功后跳转到的页面 ????????????????????????//request.getRequestDispatcher("form01.html").forward(request,response); ????????????????????} else { ????????????????????????response.getWriter().println("验证码有误,请重新输入"); ????????????????????} ????????????????} else { ????????????????????response.getWriter().println("密码有误,请重新输入"); ????????????????} ????????????}else{ ????????????????response.getWriter().println("昵称有误,请重新输入"); ????????????} ???????}else{ ???????????response.getWriter().println("昵称或密码或验证码不能为空,请输入"); ??????} ???}}

web-xml进行配置:

-<servlet><servlet-name>identifyYzmServlet</servlet-name><servlet-class>com.westos.identifyYzmServlet</servlet-class></servlet>-<servlet-mapping><servlet-name>identifyYzmServlet</servlet-name><url-pattern>/ident</url-pattern></servlet-mapping>-<servlet><servlet-name>yzmServlet</servlet-name><servlet-class>com.westos.untitle2.yzmServlet</servlet-class></servlet>-<servlet-mapping><servlet-name>yzmServlet</servlet-name><url-pattern>/yzm01</url-pattern></servlet-mapping>

html实现登录界面:

<!DOCTYPE html><html lang="en"><head> ???<meta charset="UTF-8"> ???<title>login</title> ???<style type="text/css"> ???????#login{ ???????????border: 1px solid deepskyblue; ???????????background-color: blanchedalmond; ???????????width:400px; ???????????height:250px; ???????????padding-left: 100px; ???????????padding-top: 50px; ???????} ???</style> ???<script type="text/javascript"> ???????//用javaScript语言验证昵称和密码 ???????//function check(){ ???????????//var name=document.getElementById("nicheng").value; ??????????// var password=document.getElementById("mima").value; ??????????// if(name=="Bighead"&&password=="4214963"){ ??????????????// alert("登陆成功"); ??????????????// window.document.login.action="form01.html"; ??????????????// window.document.login.submit(); ??????????// }else{ ?????????????// ?alert("密码或昵称错误,请重新输入"); ??????????// } ??????// } ??????function identifyload() { ???????????document.getElementById(‘myyzm‘).src = ‘yzm01‘; ??????} ???</script></head><body><div id="top"> ???<h1>登录</h1></div><div ?id="login"> ???<form action="./ident" method="Post" name="login"> ???????昵称:<input name="username" type="text" placeholder="请输入昵称" id="nicheng"/><br/><br/> ???????密码:<input name="password" type="password" placeholder="请输入密码" id="mima"/><br/><br/> ???????请输入验证码:<br/> ???????<img src="./yzm01" height="32" id="myyzm"> ???????<button type="button" value="看不清楚,再来一张" onclick="identifyload()">看不清楚,再来一张</button> ???????<input name="yzm01" type="text"/><br/> ???????<button type="submit" value="登录" >登录</button> ???????<button type="reset" value="重置">重置</button> ???</form></div></body></html>

Servlet结合Html实现登录验证(包括验证码验证)功能

原文地址：http://blog.51cto.com/13678728/2149091