JAVA-EE利用session机制实现用户登陆状态保持和退出登录的效果实现------计算机网络经典

今天药忘吃喽~ 2024-02-21 09:30 26阅读 0赞

>     <%@ page import="com.bjpowernode.oa.web.Pojo.Dept" %>
>     <%@ page import="java.util.List" %>
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%List<Dept> depts = (List)request.getAttribute("dept");%>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门列表</title>
>     </head>
>     <body>
>     <script>
>         function del(dno){
>             var ok = window.confirm('亲,确认删除该数据吗?');
>             if(ok){
>                 document.location.href = "<%=request.getContextPath()%>/dept/delete?deptno=" + dno;
>             }
>         }
>     </script>
>     <h3>欢迎:<a href=""><%=session.getAttribute("username")%></a></h3>
>     <h3><a href="<%=request.getContextPath()%>/user/exit">退出登录</a></h3>
>     <h1 align="center">部门列表</h1>
>     <hr>
>         <table align="center" border="1px" width="50%">
>             <tr>
>                 <th>序号</th>
>                 <th>部门编号</th>
>                 <th>部门名称</th>
>                 <th>操作</th>
>             </tr>
>             <%
>                 int count = 0;
>                 for(Dept dept : depts)
>                 {
>     
>             %>
>                 <tr>
>                     <td><%=++count%></td>
>                     <td><%=dept.getDeptno()%></td>
>                     <td><%=dept.getDname()%></td>
>                     <td>
>                         <a href="javascript:void(0)" onclick="del(<%=dept.getDeptno()%>)">删除</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=m&deptno=<%=dept.getDeptno()%>">修改</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=d&deptno=<%=dept.getDeptno()%>">详情</a>
>                     </td>
>                 </tr>
>             <%
>                 }
>             %>
>     
>         </table>
>         <hr>
>         <a href="<%=(request.getContextPath())%>/add.jsp">新增部门</a>
>     </body>
>     </html>
> 
>     <%@ page import="com.bjpowernode.oa.web.Pojo.Dept" %>
>     <%@ page import="java.util.List" %>
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%List<Dept> depts = (List)request.getAttribute("dept");%>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门列表</title>
>     </head>
>     <body>
>     <script>
>         function del(dno){
>             var ok = window.confirm('亲,确认删除该数据吗?');
>             if(ok){
>                 document.location.href = "<%=request.getContextPath()%>/dept/delete?deptno=" + dno;
>             }
>         }
>     </script>
>     <h3>欢迎:<a href=""><%=session.getAttribute("username")%></a></h3>
>     <h3><a href="<%=request.getContextPath()%>/user/exit">退出登录</a></h3>
>     <h1 align="center">部门列表</h1>
>     <hr>
>         <table align="center" border="1px" width="50%">
>             <tr>
>                 <th>序号</th>
>                 <th>部门编号</th>
>                 <th>部门名称</th>
>                 <th>操作</th>
>             </tr>
>             <%
>                 int count = 0;
>                 for(Dept dept : depts)
>                 {
>     
>             %>
>                 <tr>
>                     <td><%=++count%></td>
>                     <td><%=dept.getDeptno()%></td>
>                     <td><%=dept.getDname()%></td>
>                     <td>
>                         <a href="javascript:void(0)" οnclick="del(<%=dept.getDeptno()%>)">删除</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=m&deptno=<%=dept.getDeptno()%>">修改</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=d&deptno=<%=dept.getDeptno()%>">详情</a>
>                     </td>
>                 </tr>
>             <%
>                 }
>             %>
>     
>         </table>
>         <hr>
>         <a href="<%=(request.getContextPath())%>/add.jsp">新增部门</a>
>     </body>
>     </html>

>     package com.bjpowernode.oa.web.action;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import jakarta.servlet.http.HttpSession;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet({"/user/login","/user/exit"})
>     public class UserServlet extends HttpServlet
>     {
>         @Override
>         public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             String servletPath = request.getServletPath();
>             if("/user/login".equals(servletPath))
>             {
>                 doLogin(request,response);
>             }
>             else if("/user/exit".equals(servletPath))
>             {
>                 doExit(request,response);
>             }
>         }
>     
>         private void doExit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             HttpSession session = request.getSession(false);
>             if(session != null && session.getAttribute("username") != null)
>             {
>                 //销毁session的方法,session.invalidate()
>                 session.invalidate();
>                 response.sendRedirect(request.getContextPath() + "/index.jsp");
>             }
>         }
>         protected void doLogin(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             String username = request.getParameter("username");
>             String password = request.getParameter("password");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             boolean flag = false;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from t_user where username = ? and pssword = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,username);
>                 statement.setString(2,password);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     flag = true;
>                 }
>     
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(flag)
>             {
>                 HttpSession session = request.getSession();
>                 session.setAttribute("username",username);
>                 response.sendRedirect(request.getContextPath() + "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     }
> 
>     package com.bjpowernode.oa.web.action;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import jakarta.servlet.http.HttpSession;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet({"/user/login","/user/exit"})
>     public class UserServlet extends HttpServlet
>     {
>         @Override
>         public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             String servletPath = request.getServletPath();
>             if("/user/login".equals(servletPath))
>             {
>                 doLogin(request,response);
>             }
>             else if("/user/exit".equals(servletPath))
>             {
>                 doExit(request,response);
>             }
>         }
>     
>         private void doExit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             HttpSession session = request.getSession(false);
>             if(session != null && session.getAttribute("username") != null)
>             {
>                 //销毁session的方法,session.invalidate()
>                 session.invalidate();
>                 response.sendRedirect(request.getContextPath() + "/index.jsp");
>             }
>         }
>         protected void doLogin(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             String username = request.getParameter("username");
>             String password = request.getParameter("password");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             boolean flag = false;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from t_user where username = ? and pssword = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,username);
>                 statement.setString(2,password);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     flag = true;
>                 }
>     
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(flag)
>             {
>                 HttpSession session = request.getSession();
>                 session.setAttribute("username",username);
>                 response.sendRedirect(request.getContextPath() + "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     }