javaWeb实例--订单管理系统--用户退出登入

用户退出登入流程

用户点击主页中的退出–》/jsp/logout.do 请求–》LogoutServlet 移除session用户信息
优化：当用户退出登入后不能再访问主页等资源页面，实现权限控制
访问主页等资源页面的请求–》过滤器–》判断用户信息是否存在–》存在就能访问–》不存在就跳转到error.jsp

Logoutservlet

package com.tin.servlet;

import com.tin.util.Constants;

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

public class LogoutServlet extends HttpServlet {
     
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
     
        //移除session存储的用户信息
        req.getSession().removeAttribute(Constants.USER_SESSION);
        req.getRequestDispatcher("../login.jsp").forward(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
     
        doGet(req, resp);
    }
}

SysFilter

package com.tin.filter;

import com.tin.pojo.UserInfo;
import com.tin.util.Constants;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class SysFilter implements Filter {
     
    public void init(FilterConfig filterConfig) throws ServletException {
     
    }
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
     
        HttpServletRequest request=(HttpServletRequest) servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;
        UserInfo user = (UserInfo) request.getSession().getAttribute(Constants.USER_SESSION);
        //如果用户信息为空则转发到error.jsp
        if(user!=null){
     
            filterChain.doFilter(servletRequest,servletResponse);
        }else{
     
       		//这里是全路径
            response.sendRedirect("/ManageSystem_war/error.jsp");
        }
    }
    public void destroy() {
     

    }
}

在web.xml 注册

 
  <filter>
    <filter-name>sysFilterfilter-name>
    <filter-class>com.tin.filter.SysFilterfilter-class>
  filter>
  <filter-mapping>
    <filter-name>sysFilterfilter-name>
    <url-pattern>/jsp/*url-pattern>
  filter-mapping>
  
  <servlet>
    <servlet-name>logoutservlet-name>
    <servlet-class>com.tin.servlet.LogoutServletservlet-class>
  servlet>
  <servlet-mapping>
    <servlet-name>logoutservlet-name>
    <url-pattern>/jsp/logout.dourl-pattern>
  servlet-mapping>