SSM7.2【Spring：SpringMVC拦截器interceptor案例-用户登录权限控制】

 

package com.haifei.interceptor;

import com.haifei.domain.User;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class PrivilegeInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //逻辑：判断用户是否登录  本质：判断session中有没有user

        HttpSession session = request.getSession();
        User user = (User) session.getAttribute("user");
        if(user==null){
            //未登录 --> 重定向到登录页面
            response.sendRedirect(request.getContextPath()+"/login.jsp");
            return false;
        }else {
            //已登录 --> 放行，允许访问目标资源
            return true;
        }
    }

}

spring-mvc.xml

+

<!--配置权限拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--配置对哪些资源执行拦截操作-->
            <mvc:mapping path="/**"/>
            <!--配置哪些资源排除拦截操作-->
            <mvc:exclude-mapping path="/user/login"/>
            <bean class="com.haifei.interceptor.PrivilegeInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

 

 

UserController

+

@RequestMapping("/login")
    public String login(String username, String password, HttpSession session){
        User user = userService.login(username, password);
        if (user != null){
            //登录成功，将user存储到session
            session.setAttribute("user", user);
            return "redirect:/index.jsp";
        }else {
            //登录失败
            return "redirect:/login.jsp";
        }
    }

UserService

+

User login(String username, String password);

UserServiceImpl

+

@Override
    public User login(String username, String password) {
        User user = null;
        try {
            user = userDao.findByUsernmeAndPassword(username, password);
        } catch (EmptyResultDataAccessException e) {
//            e.printStackTrace();
        }
        return user;
    }

UserDao

+

User findByUsernmeAndPassword(String username, String password);

UserDaoImpl

+

@Override
    public User findByUsernmeAndPassword(String username, String password) throws EmptyResultDataAccessException {
        String sql = "select * from sys_user where username=? and password=?";
        User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), username, password);
        return user;
    }