struts2 在拦截器进行注入（依据Action是否实现自己定义接口）

比如：经常在Action中都须要获取当前登录的User，就须要获取Session。然后从Session获取当前登录的User，由于这些步骤都是反复操作，能够想办法在拦截器中进行实现。能够自己定义一个接口。仅仅要你的Action实现了这个接口。就在自己定义拦截器中进行注入。

即从拦截器中获取Session，然后设置进行注入。

简单的样例：

一个自己定义接口，仅仅要Action实现这个接口，就在拦截器中进行注入

package com.atguigu.surveypark.struts2;

import com.atguigu.surveypark.model.User;

/**

 * 用户关注

 */

public interface UserAware {

	public void setUser(User user);

}

一个自己定义拦截器（登录拦截器）：在拦截器中获取action的实例，假设实现上面的接口就进行注入。即调用接口的方法。

package com.atguigu.surveypark.struts2.interceptor;

import com.atguigu.surveypark.model.User;

import com.atguigu.surveypark.struts2.UserAware;

import com.atguigu.surveypark.struts2.action.BaseAction;

import com.atguigu.surveypark.struts2.action.LoginAction;

import com.atguigu.surveypark.struts2.action.RegAction;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.Interceptor;

/**

 * 登陆拦截器

 */

public class LoginInterceptor implements Interceptor {

	private static final long serialVersionUID = 4230211839075439660L;

	public void destroy() {

	}

	public void init() {

	}

	@SuppressWarnings("rawtypes")

	public String intercept(ActionInvocation arg0) throws Exception {

		BaseAction action = (BaseAction) arg0.getAction();

		if(action instanceof LoginAction

				|| action instanceof RegAction){

			return arg0.invoke();

		}

		else{

			User user = (User) arg0.getInvocationContext().getSession().get("user");

			if(user == null){

				//去登陆

				return "login" ;

			}

			else{

				//放行

				if(action instanceof UserAware){

					//注入user给action

					((UserAware)action).setUser(user);

				}

				return arg0.invoke();

			}

		}

	}

}

Action：一个实现接口的Action

package com.atguigu.surveypark.struts2.action;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.context.annotation.Scope;

import org.springframework.stereotype.Controller;

import com.atguigu.surveypark.model.Survey;

import com.atguigu.surveypark.model.User;

import com.atguigu.surveypark.service.SurveyService;

import com.atguigu.surveypark.struts2.UserAware;

/**

 * SurveyAction

 */

@Controller

@Scope("prototype")

public class SurveyAction extends BaseAction<Survey> implements UserAware{

	private static final long serialVersionUID = 2438909978838628762L;

	//注入SurveyService

	@Resource

	private SurveyService surveyService ;

	//调查集合

	private List<Survey> mySurveys ;

	//接受user对象

	private User user;

	public List<Survey> getMySurveys() {

		return mySurveys;

	}

	public void setMySurveys(List<Survey> mySurveys) {

		this.mySurveys = mySurveys;

	}

	/**

	 * 查询我的调查列表

	 */

	public String mySurveys(){

		this.mySurveys = surveyService.findMySurveys(user);

		return "mySurveyListPage" ;

	}

	/**

	 * 新建调查

	 */

	public String newSurvey(){

		this.model = surveyService.newSurvey(user);

		return "designSurveyPage" ;

	}

	//注入User对象

	public void setUser(User user) {

		this.user = user ;

	}

}

struts.xml：拦截器注冊

<?

xml version="1.0"?>

<!DOCTYPE struts PUBLIC

	"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

	"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

	<!-- 主题 -->

	<constant name="struts.ui.theme" value="simple" />

	<!-- 开发模式 -->

	<constant name="struts.devMode" value="true" />

	<package name="surveyparkPkg" extends="struts-default" namespace="/">

		<interceptors>

			<!-- 注冊登陆拦截器 -->

			<interceptor name="loginInterceptor" class="com.atguigu.surveypark.struts2.interceptor.LoginInterceptor" />

			<!-- 定义拦截器栈 -->

			<interceptor-stack name="surveyparkStack">

				<interceptor-ref name="loginInterceptor" />

				<interceptor-ref name="defaultStack" />

			</interceptor-stack>

		</interceptors>

		<!-- 定义默认栈 -->

		<default-interceptor-ref name="surveyparkStack" />

		<!-- 定义全局结果 -->

		<global-results>

			<result name="login">/index.jsp</result>

		</global-results>

		<!-- regAction -->

		<action name="RegAction_*" class="regAction" method="{1}">

			<result name="regPage">/reg.jsp</result>

			<result name="input">/reg.jsp</result>

			<result name="success">/index.jsp</result>

		</action>

		<!-- loginAction -->

		<action name="LoginAction_*" class="loginAction" method="{1}">

			<result name="loginPage">/index.jsp</result>

			<result name="input">/index.jsp</result>

			<result name="success">/index.jsp</result>

		</action>

		<!-- SurveyAction -->

		<action name="SurveyAction_*" class="surveyAction" method="{1}">

			<result name="mySurveyListPage">/mySurveyList.jsp</result>

			<result name="designSurveyPage">/designSurvey.jsp</result>

		</action>

	</package>

</struts>