登录页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><!DOCTYPE html><html><head><meta charset="UTF-8"><title>登录界面</title><style type="text/css">body{font-size:16 }</style><script type="text/javascript">function mycheck() {//判断用户名是否为空if(form1.userName.value==""){alert("用户名不能为空，请输入用户名！")form1.userName.focus();return;}//判断密码是否为空if(form1.password.value==""){alert("密码不能为空，请输入密码！")form1.password.focus();return;}//判断验证码是否为空if(form1.validationCode.value==""){alert("验证码不能为空，请输入验证码！")form1.validationCode.focus();return;}//判断验证码是否正确if(form1.validationCode.value!=form1.validationCode1.value){alert("请输入正确的验证码！")form1.validationCode.focus();return;}}</script></head><body><form action="loginCheck.jsp" name="form1" method="post">用户名：<input type="text" name="userName" size="16"><br>密 码：<input type="text" name="password"size="18"><br>验证码：<input type="text"name="validationCode"onkeydown="if(event.keyCode==13){form1.submit.focus();}" size="6"><%int intmethod1=(int)(((Math.random())*11)-1);int intmethod2=(int)(((Math.random())*11)-1);int intmethod3=(int)(((Math.random())*11)-1);int intmethod4=(int)(((Math.random())*11)-1);//将得到的随机数进行连接String intsum=intmethod1+""+intmethod2+intmethod3+intmethod4;%><!-- 设置隐藏域，验证比较时使用 --><input type="hidden" name="validationCode1" value="<%=intsum %>"><!-- 将图片名称与得到随机数相同的图片显示在页面上 --><img alt="" src="../image/<%=intmethod1%>.png"><img alt="" src="../image/<%=intmethod2%>.png"><img alt="" src="../image/<%=intmethod3%>.png"><img alt="" src="../image/<%=intmethod4%>.png"><br><input type="submit" name="submit1" value="登录" onclick="mycheck()"><input type="reset" value="重置"></form></body></html>
验证页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><!DOCTYPE html><html><head><meta charset="UTF-8"><title>处理登录页面的数据</title></head><body><%//设置请求编码，用于解决中文乱码问题request.setCharacterEncoding("UTf-8");String name=request.getParameter("userName");String password=request.getParameter("password");if(request.getParameter("validationCode1").equals(request.getParameter("validationCode"))){if(name.equals("WWW")&&(password.equals("123"))){//把用户名保存到session中session.setAttribute("userName", name);response.sendRedirect("main.jsp");}else{String script="<script>alert('用户名或密码错误，请重新登陆');location.href='login.jsp'</script>";response.getWriter().println(script);}}%></body></html>
