Spring Filter过滤器,Spring拦截未登录用户权限限制
实现的功能：判断用户是否已登录，未登录用户禁止访问任何页面或action，自动跳转到登录页面。
比较好的做法是不管什么人都不能直接访问jsp页面，要访问就通过action，这样就变成了一个实实在在的权限控制了。
那么就有3种方法可以解决楼主的问题
1，直接使用filter
2，直接使用webwork的interceptor，
3，将action交给spring管理，使用spring的Aop机制
让用户可以直接访问jsp本来就违反了mvc的本意了
1 直接使用filter
web.xml配置
<filter> <filter-name>SecurityServlet</filter-name> <filter-class>com.*.web.servlet.SecurityServlet</filter-class> </filter> <filter-mapping> <filter-name>SecurityServlet</filter-name> <url-pattern>*.jsp</url-pattern> </filter-mapping> <filter-mapping> <filter-name>SecurityServlet</filter-name> <url-pattern>*.do</url-pattern> </filter-mapping>
SecurityServlet 类
package com.*.web.servlet;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class SecurityServlet extends HttpServlet implements Filter {private static final long serialVersionUID = 1L;public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException { HttpServletRequest request=(HttpServletRequest)arg0; HttpServletResponse response =(HttpServletResponse) arg1; HttpSession session = request.getSession(true); String usercode = (String) request.getRemoteUser();// 登录人 String user_role = (String)session.getAttribute("role");//登录人角色 String url=request.getRequestURI(); if(usercode==null || "".equals(usercode) || user_role == null || "".equals(user_role)) { //判断获取的路径不为空且不是访问登录页面或执行登录操作时跳转 if(url!=null && !url.equals("") && ( url.indexOf("Login")<0 && url.indexOf("login")<0 )) { response.sendRedirect(request.getContextPath() + "/login.jsp"); return ; } } arg2.doFilter(arg0, arg1); return; }public void init(FilterConfig arg0) throws ServletException {}}配置中的filter-mapping，定义的是需过滤的请求类型，上面的配置即过滤所有对jsp页面和action的请求。过滤器的实现与struts2、spring框架无关，在用户请求被相应前执行，在过滤器中，可使用response.sendRedirect("")等方法
跳转到需要的链接，如登录页面、错误页面等，不需要跳转时，arg2.doFilter(arg0, arg1);即可继续执行用户的请求。注意使用filter时避免连续两次跳转，否则会报java.lang.IllegalStateException错误，具体配置方法网上有，除非必要，不建议使用/*(过滤所有访问)的配置方式，这样配置，图片、js文件、css文件等访问都会被过滤
2 Spring拦截
Spring配置
<bean id="springSessionInterceptor" > </bean><bean id="autoPorxyFactoryBean1"><list><value>*Controller</value></list></property></bean>
SpringLoginInterceptor实现类
package com.web.servlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.aopalliance.intercept.MethodInterceptor;import org.aopalliance.intercept.MethodInvocation;import org.apache.log4j.Logger;import org.apache.struts.action.ActionMapping;public class SpringLoginInterceptor implements MethodInterceptor {private static final Logger log = Logger.getLogger(SpringLoginInterceptor .class);@Overridepublic Object invoke(MethodInvocation invocation) throws Throwable {log.info("拦截开始！");Object[] args = invocation.getArguments(); HttpServletRequest request = null;HttpServletResponse response = null;ActionMapping mapping = null;for (int i = 0 ; i < args.length ; i++ ) { if (args[i] instanceof HttpServletRequest) request = (HttpServletRequest)args[i]; if (args[i] instanceof HttpServletResponse) response = (HttpServletResponse)args[i]; if (args[i] instanceof ActionMapping) mapping = (ActionMapping)args[i]; }if (request != null && mapping != null) {String url=request.getRequestURI(); HttpSession session = request.getSession(true); String usercode = (String) request.getRemoteUser();// 登录人 String user_role = (String)session.getAttribute("user_role");//登录人角色 if (usercode == null || usercode.equals("")) {if ( url.indexOf("Login")<0 && url.indexOf("login")<0 ) {return mapping.findForward("loginInterceptor");} return invocation.proceed(); } else { return invocation.proceed(); }}else {return invocation.proceed();}}}