• springMVC_11拦截器实现登录


    一.   思路

    1. controller实现核对用户名和密码,如果核对正确则保存到session中并且跳转到主页
    2. 系统中包含诸多界面,部分界面不需要登录即可进行访问,通过拦截器实现判断是否是不需要登录的界面和用户是否登录(通过session),如果登录或者是不需要登陆的见面,则不进行拦截,如果不满足上述条件,则跳转到登录页面,拦截器返回false

    二.   案例

      1.导入jar包 

      commons-logging-1.1.1.jar
      jackson-annotations-2.5.4.jar
      jackson-core-2.5.4.jar
      jackson-databind-2.5.4.jar
      spring-aop-4.1.6.RELEASE.jar
      spring-beans-4.1.6.RELEASE.jar
      spring-context-4.1.6.RELEASE.jar
      spring-core-4.1.6.RELEASE.jar
      spring-expression-4.1.6.RELEASE.jar
      spring-tx-4.1.6.RELEASE.jar
      spring-web-4.1.6.RELEASE.jar
      spring-webmvc-4.1.6.RELEASE.jar

      如果使用上传文件功能,需要额外导入

      commons-fileupload-1.2.2.jar
      commons-io-2.0.1.jar

      2.配置web.xml文件

      
    <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>05springMVC_data_2</display-name>
          
      <!-- 过滤实现表单数据传输过程编码问题 -->
      <filter>
          <filter-name>encoding</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>encoding</filter-name>
          <url-pattern>*.do</url-pattern>
      </filter-mapping>
      
      <!--springMVC标配  -->
      <servlet>
          <servlet-name>springmvc</servlet-name>
          <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!—设置controller配置文件位置-->
          <init-param>
              <param-name>contextConfigLocation</param-name>
              <param-value>classpath:mvc.xml</param-value>
          </init-param>
          <load-on-startup>1</load-on-startup>
    
      </servlet>
      <servlet-mapping>
          <servlet-name>springmvc</servlet-name>
          <url-pattern>*.do</url-pattern>
      </servlet-mapping>
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
    </web-app>
    web.xml

      

      3.创建配置文件mvc.xml在目录src下

      4.用户实体类User

      
    package com.ahd.entity;
    
    public class User {
        private String username;
        private String password;
        
        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;
        }
        @Override
        public String toString() {
            return "User [username=" + username + ", password=" + password + "]";
        }
    }
    User

      5.创建controller类LoginController

    package com.ahd.controller;
    
    import javax.servlet.http.HttpSession;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.ModelMap;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    import com.ahd.entity.User;
    
    @Controller
    public class LoginController {
        @RequestMapping("/login")
        public String Login(User user,HttpSession session){
            if(user.getUsername().equals("ahdg")&&user.getPassword().equals("111111")){
                session.setAttribute("user", user);
                return "index.jsp";
            }
            return "login.jsp";
        }
        
        @RequestMapping("/add") //本方法为测试方法
        public String add(User user,HttpSession session){
            System.out.println("add");
            return "index.jsp";
        }
    }

      6.创建拦截器类LoginController

    package com.ahd.interceptor;
    
    import java.util.List;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    public class LoginInterceptor implements HandlerInterceptor{
        //设置不被拦截的页面
        private List<String> allowedPass;
        
        
        @Override
        public void afterCompletion(HttpServletRequest arg0,
                HttpServletResponse arg1, Object arg2, Exception arg3)
                throws Exception {
            // TODO Auto-generated method stub
            
        }
    
        @Override
        public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
                Object arg2, ModelAndView arg3) throws Exception {
            // TODO Auto-generated method stub
            
        }
    
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                Object arg2) throws Exception {
            // TODO Auto-generated method stub
            //获取url地址
            String url=request.getRequestURI().toString();
            
            //先判断session中是否有登录信息
            Object user=request.getSession().getAttribute("user");
            if(user!=null){
                return true;
            }
            
            for(String temp:allowedPass){
                if(url.endsWith(temp)){
                    return true;
                }
            }
            response.sendRedirect(request.getContextPath()+"/login.jsp");
            return false;
        }
        
        public void setAllowedPass(List allowedPass) {
            this.allowedPass = allowedPass;
        }
        
    }

      7.配置mvc.xml文件

    <?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:p="http://www.springframework.org/schema/p"
        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.xsd 
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd 
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd">
        <!-- 配置handerAdapter  适配器 -->
        <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
       <!-- 文件上传配置 -->
        <bean id="multipartResolver"  
            class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
            <!-- 设置编码格式 -->  
            <property name="defaultEncoding" value="utf-8"></property> 
            <!-- 设置文件大小 -->  
            <property name="maxUploadSize" value="10485760000"></property>
            <!-- 设置缓冲区大小 -->  
            <property name="maxInMemorySize" value="40960"></property>  
        </bean> 
        
        <mvc:interceptors>
            <mvc:interceptor>
                <mvc:mapping path="/**"/>
                <bean class="com.ahd.interceptor.LoginInterceptor">
                    <property name="allowedPass">
                        <list>
                            <value>login.do</value>
                        </list>
                    </property>
                </bean>
            </mvc:interceptor>
        </mvc:interceptors>
    
        
        <!-- spring容器扫描指定包下的所有类,如果类上有注解  那么根据注解产生相应bean对象已经映射信息 -->
        <context:component-scan base-package="com.ahd.controller"/>
        
    </beans>

      

      8.编写前端页面

        index.jsp

        
    <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'index.jsp' starting page</title>
        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">    
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <!--
        <link rel="stylesheet" type="text/css" href="styles.css">
        -->
      </head>
      
      <body>
        ${user}<br/>
        
        <a href="fileupload.jsp" >文件上传fileupload.jsp</a><br/>
        <a href="fileupload1.jsp" >文件批量上传fileupload.jsp</a><br/>
        <a href="login.jsp" >登录</a>
      </body>
    </html>
    index.jsp

        login.jsp

        
    <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'login.jsp' starting page</title>
        
        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">    
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <!--
        <link rel="stylesheet" type="text/css" href="styles.css">
        -->
    
      </head>
      
      <body>
        <form action="login.do" method="post">
            用户名:<input type="text" name="username" /><br/>
            密    码:<input type="password" name="password" /><br/>
            <input type="submit" value="submit" /><br/>
        </form>
      </body>
    </html>
    login.jsp
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  • 原文地址:https://www.cnblogs.com/aihuadung/p/10185108.html
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