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..jar
　　jackson-annotations-2.5..jar
　　jackson-core-2.5..jar
　　jackson-databind-2.5..jar
　　spring-aop-4.1..RELEASE.jar
　　spring-beans-4.1..RELEASE.jar
　　spring-context-4.1..RELEASE.jar
　　spring-core-4.1..RELEASE.jar
　　spring-expression-4.1..RELEASE.jar
　　spring-tx-4.1..RELEASE.jar
　　spring-web-4.1..RELEASE.jar
　　spring-webmvc-4.1..RELEASE.jar

　　如果使用上传文件功能,需要额外导入

　　commons-fileupload-1.2..jar
　　commons-io-2.0..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