【Spring MVC】教程——使用攔截器實現權限控制

目錄(?)[+]

之前一直都在用mvc的攔截器權限控制，後來上網也研究了一些這方面的知識，下面就直接分享下我對mvc的攔截器的理解，通過項目來分析吧。。。

1、首先準備對應的架包

2、看看項目的架構

3、基本的web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <display-name>shiro</display-name>

    <!-- 加載springmvc -->
    <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:mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- 以.htm結尾的都被mvc攔截 -->
    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <url-pattern>*.htm</url-pattern>
    </servlet-mapping>

    <!-- 啓動spring 加載   需要加載其他的spring時 需啓動該監聽器
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
     -->
</web-app>

3、配置classpath下的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-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
    <mvc:annotation-driven />
    <!-- 自動掃描包 -->
    <context:component-scan base-package="com.cat.spring.controller" />

    <!--  配置mvc的攔截器 可以配置多個 -->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--  需要被攔截的路徑 -->
            <mvc:mapping path="/member/**" />
            <!-- 攔截處理的interceptor -->
            <bean class="com.cat.interceptor.MemberInterceptor" />
        </mvc:interceptor>
    </mvc:interceptors>

    <!-- mvc返回頁面的配置 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- 模板路徑爲WEB-INF/pages/ -->
        <property name="prefix">
            <value>/WEB-INF/pages/</value>
        </property>
        <!-- 視圖模板後綴爲.JSP -->
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

</beans>

4、接着就要配置攔截器了MemberInterceptor.java

/**
 *
 */
package com.cat.interceptor;

import java.net.URLEncoder;

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

import org.apache.commons.lang.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

/**
 * @author chenlf
 *
 *         2014-3-25
 */
public class MemberInterceptor implements HandlerInterceptor {

    public final static String SEESION_MEMBER = "seesion_member";

    /*
     * (non-Javadoc)
     *
     * @see org.springframework.web.servlet.HandlerInterceptor#afterCompletion(javax.servlet.http.HttpServletRequest,
     * javax.servlet.http.HttpServletResponse, java.lang.Object, java.lang.Exception)
     */
    public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2,
            Exception arg3) throws Exception {
        // TODO Auto-generated method stub

    }

    /*
     * (non-Javadoc)
     *
     * @see org.springframework.web.servlet.HandlerInterceptor#postHandle(javax.servlet.http.HttpServletRequest,
     * javax.servlet.http.HttpServletResponse, java.lang.Object, org.springframework.web.servlet.ModelAndView)
     */
    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2,
            ModelAndView arg3) throws Exception {
        // TODO Auto-generated method stub

    }

    /*
     * (non-Javadoc)
     * 攔截mvc.xml配置的/member/**路徑的請求
     * @see org.springframework.web.servlet.HandlerInterceptor#preHandle(javax.servlet.http.HttpServletRequest,
     * javax.servlet.http.HttpServletResponse, java.lang.Object)
     */
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
            Object handler) throws Exception {
        //請求的路徑
        String contextPath=request.getContextPath();
        String  url=request.getServletPath().toString();
        HttpSession session = request.getSession();
        String user = (String) session.getAttribute(SEESION_MEMBER);
        //這裏可以根據session的用戶來判斷角色的權限，根據權限來重定向不同的頁面，簡單起見，這裏只是做了一個重定向
        if (StringUtils.isEmpty(user)) {
            //被攔截，重定向到login界面
            response.sendRedirect(contextPath+"/login.htm?redirectURL="
                    + URLEncoder.encode(url));
            return false;
        }
        return true;
    }

}

這樣攔截器的核心就配置完了，接下來就是一些登陸的處理操作

5、LoginController.java文件

/**
 *
 */
package com.cat.spring.controller;

import java.net.URLDecoder;

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

import org.apache.commons.lang.StringUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.cat.interceptor.MemberInterceptor;

/**
 * @author chenlf
 *
 *         2014-3-24
 */
@Controller
public class LoginController {

    @RequestMapping(value = "/login", method = RequestMethod.GET)
    public ModelAndView login(String redirectURL, HttpServletRequest request) {
        ModelAndView view = new ModelAndView();
        //把攔截前路徑存下來，以便登入成功可以直接請求到登錄前的頁面
        view.addObject("redirectURL", redirectURL);
        view.setViewName("/login");
        return view;
    }

    @RequestMapping(value = "/submit", method = RequestMethod.POST)
    public String submit(String username, String password, String redirectURL,
            HttpServletRequest request) {
        //模擬登陸成功 用戶admin 密碼admin的用戶
        if (StringUtils.isNotBlank(username) && StringUtils.isNotBlank(password)
                && username.equals("admin") && password.equals("admin")) {
            //當登陸成功是，將用戶信息存放到session中去
            HttpSession session = request.getSession();
            session.setAttribute(MemberInterceptor.SEESION_MEMBER, "admin");
            if (StringUtils.isNotBlank(redirectURL)) {
                return "redirect:" + URLDecoder.decode(redirectURL);
            }
            return "redirect:/member/index.htm";
        } else {
            if (StringUtils.isNotBlank(redirectURL)) {
                return "redirect:/login.htm?" + URLDecoder.decode(redirectURL);
            }
            return "redirect:/login.htm";
        }
    }
}

6、下面就是login.jsp文件

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>mvc權限登陸login</title>
    </head>
    <body>
        <h3>
            mvc權限登陸login
        </h3>
        <form action="submit.htm" method="post">
            <!-- 記錄重定向的url -->
            <input type="hidden" name="redirectURL" value="${redirectURL}" />
            <table>
                <tr>
                    <td>
                        賬號
                    </td>
                    <td>
                        <input type="text" name="username" />
                    </td>
                    <td>
                        密碼
                    </td>
                    <td>
                        <input type="password" name="password" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2" align="center">
                        <input type="submit" value="提交" />
                    </td>
                </tr>
            </table>
        </form>
    </body>
</html>

7、剩下的就是一些正常的mvc請求處理的文件，這裏就不贅訴了

8、到這裏看看效果吧

a、當非登陸狀態的時候，請求localhost:8010/demo-mvc/member/list.htm時，被攔截攔截，重定向到login頁面，並攜帶了當前的這個路徑（/member/list.htm）作爲參數傳到頁面

b、輸入正確的用戶名admin 密碼admin後登陸，會跳轉到攔截前的頁面

c、當登陸完成後，輸入地址爲http://localhost:8010/demo-mvc/member/index.htm，session中記錄着當前用戶的信息，不需要重新登陸了

9、因爲篇幅問題，一些不重要的文件沒有一一貼出來，有需要的可以到http://download.csdn.net/detail/a124753561/7098925下載源代碼。