【Spring MVC】教程——使用拦截器实现权限控制
之前一直都在用mvc的拦截器权限控制，后来上网也研究了一些这方面的知识，下面就直接分享下我对mvc的拦截器的理解，通过项目来分析吧。。。
1、首先准备对应的架包
2、看看项目的架构
3、基本的web.xml文件
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<!--?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>
<!-- 加载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结尾的都被mvc拦截 -->
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
<!-- 启动spring 加载 需要加载其他的spring时 需启动该监听器
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
-->
</web-app> |
3、配置classpath下的mvc.xml文件
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<!--?xml version="1.0"
encoding="UTF-8"?-->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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>
<!-- 自动扫描包 -->
<context:component-scan base-package="com.cat.spring.controller">
<!-- 配置mvc的拦截器 可以配置多个 -->
<mvc:interceptors>
<mvc:interceptor>
<!-- 需要被拦截的路径 -->
<mvc:mapping path="/member/**">
<!-- 拦截处理的interceptor -->
<bean
class="com.cat.interceptor.MemberInterceptor">
</bean></mvc:mapping></mvc:interceptor>
</mvc:interceptors>
<!-- mvc返回页面的配置 -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="viewResolver">
<!-- 模板路径为WEB-INF/pages/ -->
<property name="prefix">
<value>/WEB-INF/pages/</value>
</property>
<!-- 视图模板后缀为.JSP -->
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
</context:component-scan></mvc:annotation-driven></beans> |
4、接着就要配置拦截器了MemberInterceptor.java
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/** *
*/
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)
* 拦截mvc.xml配置的/member/**路径的请求
* @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 {
//请求的路径
String contextPath=request.getContextPath();
String url=request.getServletPath().toString();
HttpSession session = request.getSession();
String user = (String) session.getAttribute(SEESION_MEMBER);
//这里可以根据session的用户来判断角色的权限，根据权限来重定向不同的页面，简单起见，这里只是做了一个重定向
if
(StringUtils.isEmpty(user)) {
//被拦截，重定向到login界面
response.sendRedirect(contextPath+"/login.htm?redirectURL="
+ URLEncoder.encode(url));
return
false;
}
return
true;
}
} |
5、LoginController.java文件
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/** *
*/
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
*/
@Controllerpublic
class LoginController {
@RequestMapping(value =
"/login", method = RequestMethod.GET)
public
ModelAndView login(String redirectURL, HttpServletRequest request) {
ModelAndView view =
new ModelAndView();
//把拦截前路径存下来，以便登入成功可以直接请求到登录前的页面
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) {
//模拟登陆成功 用户admin 密码admin的用户
if
(StringUtils.isNotBlank(username) && StringUtils.isNotBlank(password)
&& username.equals("admin") && password.equals("admin"))
{
//当登陆成功是，将用户信息存放到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
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<%@ page language="java"
contentType="text/html; charset=UTF-8"
pageEncoding="utf-8"%>
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mvc权限登陆login
7、剩下的就是一些正常的mvc请求处理的文件，这里就不赘诉了
8、到这里看看效果吧
a、当非登陆状态的时候，请求localhost:8010/demo-mvc/member/list.htm时，被拦截拦截，重定向到login页面，并携带了当前的这个路径（/member/list.htm）作为参数传到页面b、输入正确的用户名admin 密码admin后登陆，会跳转到拦截前的页面
c、当登陆完成后，输入地址为http://localhost:8010/demo-mvc/member/index.htm，session中记录着当前用户的信息，不需要重新登陆了