由于书上的例子弄不出来
自己瞎弄了个简易版的
登陆页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'login.jsp' starting page</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 rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <div name="error"> <% String errorMessage = request.getAttribute("errorMessage").toString(); if (errorMessage != ""){ %> <%=errorMessage %> <%} %> </div> <form action="logout.jsp" method="post"> 用户:<input type="text" name="name"> 密码:<input type="text" name="password"> <br/> <input type="radio" name="jurisdiction" value="guest">guest <br/> <input type="radio" name="jurisdiction" value="administrator">administrator <br/> <input type="submit" value="click"> </form> </body> </html>