springmvc拦截器实现用户登录权限验证

素颜马尾好姑娘i 2023-06-25 02:19 65阅读 0赞

实现用户登录权限验证  
先看一下我的项目的目录，我是在intellij idea 上开发的  
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1、先创建一个User类

package cn.lzc.po;
    
    public class User { 
        private Integer id;//id
        private String username;//用户名
        private String password;//密码
    
        public Integer getId() { 
            return id;
        }
    
        public void setId(Integer id) { 
            this.id = id;
        }
    
        public String getUsername() { 
            return username;
        }
    
        public void setUsername(String username) { 
            this.username = username;
        }
    
        public String getPassword() { 
            return password;
        }
    
        public void setPassword(String password) { 
            this.password = password;
        }
    }

2、创建一个UserController类

package cn.lzc.controller;
    
    import cn.lzc.po.User;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    
    import javax.servlet.http.HttpSession;
    
    @Controller
    public class UserController { 
        /** * 向用户登录页面跳转 */
        @RequestMapping(value = "/login",method = RequestMethod.GET)
        public String toLogin(){ 
            return  "login";
        }
    
        /** * 用户登录 * @param user * @param model * @param session * @return */
        @RequestMapping(value = "/login",method = RequestMethod.POST)
        public String login(User user, Model model, HttpSession session){ 
            //获取用户名和密码
            String username=user.getUsername();
            String password=user.getPassword();
            //些处横板从数据库中获取对用户名和密码后进行判断
            if(username!=null&&username.equals("admin")&&password!=null&&password.equals("admin")){ 
                //将用户对象添加到Session中
                session.setAttribute("USER_SESSION",user);
                //重定向到主页面的跳转方法
                return "redirect:main";
            }
            model.addAttribute("msg","用户名或密码错误，请重新登录！");
            return "login";
        }
    
        @RequestMapping(value = "/main")
        public String toMain(){ 
            return "main";
        }
        
        @RequestMapping(value = "/logout")
        public String logout(HttpSession session){ 
            //清除session
            session.invalidate();
            //重定向到登录页面的跳转方法
            return "redirect:login";
        }
        
    }

3、创建一个LoginInterceptor类

package cn.lzc.interceptor;
    
    import cn.lzc.po.User;
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    
    public class LoginInterceptor implements HandlerInterceptor { 
    
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception { 
            //获取请求的RUi:去除http:localhost:8080这部分剩下的
            String uri = request.getRequestURI();
            //UTL:除了login.jsp是可以公开访问的，其他的URL都进行拦截控制
            if (uri.indexOf("/login") >= 0) { 
                return true;
            }
            //获取session
            HttpSession session = request.getSession();
            User user = (User) session.getAttribute("USER_SESSION");
            //判断session中是否有用户数据，如果有，则返回true，继续向下执行
            if (user != null) { 
                return true;
            }
            //不符合条件的给出提示信息，并转发到登录页面
            request.setAttribute("msg", "您还没有登录，请先登录！");
            request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
            return false;
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception { 
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception { 
    
        }
    }

4、看一下springmvc-config.xml中配置的拦截器

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xmlns:tx="http://www.springframework.org/schema/tx"
            xmlns:context="http://www.springframework.org/schema/context"
            xmlns:mvc="http://www.springframework.org/schema/mvc"
            xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
        
        <context:component-scan base-package="cn.lzc.controller"/>
        
        <mvc:annotation-driven/>
        
        <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/WEB-INF/jsp/"/>
            <property name="suffix" value=".jsp"/>
        </bean>
        
        <mvc:interceptors>
          
           
            
            
            
               
                
            
            
            
            <mvc:interceptor>
                <mvc:mapping path="/**"/>
                <bean class="cn.lzc.interceptor.LoginInterceptor"/>
            </mvc:interceptor>
        </mvc:interceptors>
    </beans>

5、看下web.xml的配置

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
             version="4.0">
        
        <filter>
            <filter-name>CharacterEncodingFilter</filter-name>
            <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
            <init-param>
                <param-name>encoding</param-name>
                <param-value>utf-8</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>CharacterEncodingFilter</filter-name>
            <url-pattern>/*</url-pattern>  </filter-mapping>  <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-config.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>

6、WEB-INF目录下的main.jsp

<%--
      Created by IntelliJ IDEA.
      User: admin
      Date: 2018-04-07
      Time: 13:02
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>系统主页</title>
    </head>
    <body>
        当前用户：${ USER_SESSION.username}
        <a href="${pageContext.request.contextPath}/logout">退出</a>
    </body>
    </html>

7、WEB-INF目录下的login.jsp

<%--
      Created by IntelliJ IDEA.
      User: admin
      Date: 2018-04-07
      Time: 13:04
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>用户登录</title>
    </head>
    <body>
        ${ msg}
        <form action="${pageContext.request.contextPath}/login" method="post">
            用户名：<input type="text" name="username"><br>
            密   码:
            <input type="password" name="password"><br>
            <input type="submit" value="登录">
        </form>
    </body>
    </html>

8、启动tomcat,可以访问了 http://localhost:8080/chater15/interceptor/login  
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