前台开发——开发导航菜单栏的登录后退出和后台管理的显示与否

开发登录后导航菜单的显示

  1 <%@ page language="java" contentType="text/html; charset=UTF-8"
  2     pageEncoding="UTF-8"%>
  3      <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
  4 <!DOCTYPE html>
  5 <html>
  6 <head>
  7 <meta charset="UTF-8">
  8 <title>header</title>
  9 </head>
 10 <body>
 11 
 12 
 13     <!--header-->
 14     <div class="header">
 15         <div class="container">
 16             <nav class="navbar navbar-default" role="navigation">
 17                 <div class="navbar-header">
 18                     <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
 19                         <span class="sr-only">Toggle navigation</span>
 20                         <span class="icon-bar"></span>
 21                         <span class="icon-bar"></span>
 22                         <span class="icon-bar"></span>
 23                     </button>
 24                     <h1 class="navbar-brand"><a href="${pageContext.request.contextPath }">言馨*</a></h1>
 25                 </div>
 26                 <!--navbar-header-->
 27                 <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
 28                     <ul class="nav navbar-nav">
 29                         <li><a href="${pageContext.request.contextPath }"  <c:if test="${param.flag==1 }">class="active"</c:if>>首页</a></li>
 30                         <li class="dropdown">
 31                             <a href="#" class="dropdown-toggle <c:if test="${param.flag==2 }">active</c:if>" data-toggle="dropdown"  >商品分类<b class="caret"></b></a>
 32                             <ul class="dropdown-menu multi-column columns-2">
 33                                 <li>
 34                                     <div class="row">
 35                                         <div class="col-sm-12">
 36                                             <h4>商品分类</h4>
 37                                             <ul class="multi-column-dropdown">
 38                                                 
 39                                                     <li><a class="list" href="${pageContext.request.contextPath }/goods_list">全部系列</a></li>
 40                                                 <c:forEach items="${typeList }" var="t" >
 41                                                 <li><a class="list" href="${pageContext.request.contextPath }/goods_list?id=${t.id}">${t.name}</a></li>
 42                                                 
 43                                                 
 44                                                 </c:forEach>
 45                                                     
 46                                                 
 47                                                     
 48                                                 
 49                                             </ul>
 50                                         </div>    
 51                                     </div>
 52                                 </li>
 53                             </ul>
 54                         </li>
 55                         <!-- 根据type的不同来进行区分热销和新品 -->
 56                         <li><a href="${pageContext.request.contextPath }/goodsrecommend_list?type=2"  <c:if test="${param.flag==3&&t==2 }">class="active"</c:if> >热销</a></li>
 57                         <li><a href="${pageContext.request.contextPath }/goodsrecommend_list?type=3"  <c:if test="${param.flag==3&&t==3 }">class="active"</c:if>>新品</a></li>
 58                         
 59                             <c:choose><c:when test="${empty user }">
 60                             <li><a href="${pageContext.request.contextPath }/user_register.jsp" >注册</a></li>
 61                             <li><a href="${pageContext.request.contextPath }/user_login.jsp" >登录</a></li>
 62                             </c:when><c:otherwise>
 63                         
 64                         <li><a href="${pageContext.request.contextPath }/user_center.jsp" <c:if test="${param.flag==4 }">class="active"</c:if> >个人中心</a></li>
 65                             <li><a href="${pageContext.request.contextPath }/user_logut.jsp" >退出</a></li>
 66                         
 67                         </c:otherwise>
 68                         </c:choose>
 69                         <li><a href="../admin.jsp" target="_blank">后台管理</a></li>
 70                         
 71                     </ul> 
 72                     <!--/.navbar-collapse-->
 73                 </div>
 74                 <!--//navbar-header-->
 75             </nav>
 76             <div class="header-info">
 77                 <div class="header-right search-box">
 78                     <a href="javascript:;"><span class="glyphicon glyphicon-search" aria-hidden="true"></span></a>                
 79                     <div class="search">
 80                         <form class="navbar-form" action="search.action">
 81                             <input type="text" class="form-control" name="name">
 82                             <button type="submit" class="btn btn-default" aria-label="Left Align">搜索</button>
 83                         </form>
 84                     </div>    
 85                 </div>
 86                 
 87                 <div class="header-right cart">
 88                     <a href="cart.action">
 89                         <span class="glyphicon glyphicon-shopping-cart" aria-hidden="true"><span class="card_num">0</span></span>
 90                     </a>
 91                 </div>
 92                 <div class="header-right login">
 93                     <a href="my.action"><span class="glyphicon" aria-hidden="true"></span></a>
 94                 </div>
 95                 <div class="clearfix"> </div>
 96             </div>
 97             <div class="clearfix"> </div>
 98         </div>
 99     </div>
100     <!--//header-->
101 
102 </body>
103 </html>

header.jsp

                            <c:choose><c:when test="${empty user }">
                            <li><a href="${pageContext.request.contextPath }/user_register.jsp" >注册</a></li>
                            <li><a href="${pageContext.request.contextPath }/user_login.jsp" >登录</a></li>
                            </c:when><c:otherwise>
                        
                        <li><a href="${pageContext.request.contextPath }/user_center.jsp" <c:if test="${param.flag==4 }">class="active"</c:if> >个人中心</a></li>
                            <li><a href="${pageContext.request.contextPath }/user_logut.jsp" >退出</a></li>
                        
                        </c:otherwise>
                        </c:choose>

开发登录后退出和后台管理的显示与否

实现退出，创建一个servlet类UserLogutServlet：

package com.guiyan.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class UserLogutServlet
 */
@WebServlet("/user_logut")
public class UserLogutServlet extends HttpServlet {
    
    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        
        request.getSession().removeAttribute("user");
        response.sendRedirect(request.getContextPath());
    }

    

}

导航栏中的后台管理不能一直出现，需要是管理员才能显示：因此在数据库中加入管理员

admin是管理员isadmin=1

在header.jsp导航栏中的后台管理中加一个管理员的权限isadmin=1时这个后台管理的才会显示出来。

<c:if test="${!empty user && user.isadmin }"><!-- 获得管理员的权限 -->
                        <li><a href="../admin.jsp" target="_blank">后台管理</a></li>
                        </c:if>

最终效果图：