java自定义拦截器用法实例

package com.tq365.util;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionInvocation;import com.opensymphony.xwork2.interceptor.AbstractInterceptor;import com.tq365.vo.User;/** * 自定义的拦截器（放行登录操作和已经登录用户的操作） * @author archie2010 * */public class LoginInterceptor extends AbstractInterceptor{  private static final long serialVersionUID = 1406123004582563032L;  @Override  public String intercept(ActionInvocation invocation) throws Exception {    HttpServletRequest request = ServletActionContext.getRequest();    HttpSession session = ServletActionContext.getRequest().getSession();    User user = (User)session.getAttribute("USER");    // 请求的url    String path = request.getServletPath();    boolean flag = false;    if("/loginuser.jspx".equals(path)){      flag = true;    }else{      if(user!=null){        flag = true;      }    }    System.out.println(path);    return flag ? invocation.invoke() : "error";  }}

<interceptors>  <!-- login拦截器 -->  <interceptor name="login" class="com.tq365.util.LongInterceptor"/>  <interceptor-stack name="myInterceptor"> <interceptor-ref name="login"/> <interceptor-ref name="paramsPrepareParamsStack"/>  </interceptor-stack></interceptors><default-interceptor-ref name="myInterceptor"/>