使用struts2 拦截器实现判断是否登录功能

package com.iapppay.maintain.common;

import java.util.Map;

import org.jasypt.commons.CommonUtils;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;

public class LoginInterceptor extends MethodFilterInterceptor  {

    private static final long serialVersionUID = 3590018080122600795L;
    @Override
    protected String doIntercept(ActionInvocation arg0) throws Exception {
        ActionContext act=arg0.getInvocationContext();
        Map session = act.getSession();
        String user=(String) session.get("user");
        if(!CommonUtils.isEmpty(user)){
            return arg0.invoke();
        }
        return Action.LOGIN;
    }
}

struts.xml配置

<interceptors>
            <interceptor name="loginInterceptor" class="com.iapppay.maintain.common.LoginInterceptor" />
            <interceptor-stack name="maintainInterceptor">
                <interceptor-ref name="loginInterceptor">
                    <param name="excludeMethods">index,login</param>
                </interceptor-ref>
                <interceptor-ref name="defaultStack" />
            </interceptor-stack>
</interceptors>
<default-interceptor-ref name="maintainInterceptor" />