JavaWeb26（SMBMS项目搭建03）

登录功能优化

实现注销功能

• 移除session
• 返回登陆页面

LogoutServlet.java

package com.hao.servlet.user;

import com.hao.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 {
    
    
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //移除Session
        req.getSession().removeAttribute(Constants.USER_SESSION);
        //返回登陆页面
        resp.sendRedirect(req.getContextPath()+"/login.jsp");
    }
}

在xml中注册

<!--    注销-->
    <servlet>
        <servlet-name>LogoutServlet</servlet-name>
        <servlet-class>com.hao.servlet.user.LogoutServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LogoutServlet</servlet-name>
        <url-pattern>/jsp/logout.do</url-pattern>
    </servlet-mapping>

登录拦截优化

• 编写过滤器
• 注册过滤器

SysFilter.java

package com.hao.filter;

import com.hao.pojo.User;
import com.hao.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;
        User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);
        if (user==null){
    
    //说明对象已被移除
            response.sendRedirect("/SMBMS/error.jsp");
        }else{
    
    
            filterChain.doFilter(servletRequest,servletResponse);
        }


    }

    public void destroy() {
    
    

    }
}

注册

<!--    登陆过滤器-->
    <filter>
        <filter-name>SysFilter</filter-name>
        <filter-class>com.hao.filter.SysFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>SysFilter</filter-name>
        <url-pattern>/jsp/*</url-pattern>
    </filter-mapping>

访问测试

• 正常登录
  
• 退出
  
• 直接访问网址