struts2 拦截器

struts2拦截器的原理是AOP的，的运用

下面我的配置struts2的拦截器

首先在struts2.xml里面配置

<interceptors>
            <interceptor name="fileDownload" class="com.wen.interceptor.FileDownloadInserceptor"/>
            <interceptor-stack name="myStack">
                <interceptor-ref name="fileDownload"/>
            </interceptor-stack>
        </interceptors>
        <!-- 定义全局Result -->
        <global-results>
            <!-- 当返回login视图名时，转入/index.jsp页面 -->
            <result name="login">/index.jsp</result>
        </global-results>

可以把相应的拦截器名称放入需要拦截的配置的struts2中配置的action中

<interceptor-ref name="fileDownload"/>

建立拦截器

package com.wen.interceptor;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.wen.bean.person.User;

/** 拦截器
 * Created by Administrator on 2016-09-09.
 */
public class FileDownloadInserceptor extends AbstractInterceptor  {
    @Override
    public String intercept(ActionInvocation actionInvocation) throws Exception {
        String result="";
        User user = (User) ActionContext.getContext().getSession().get("currentUser");
        if(user == null){
            System.out.println("进入这个方法");
           return "login";
        }else {
            result =actionInvocation.invoke();
            return result;
        }
    }
}