public String execute() throws Exception {

        this.message="hello,this is put into application!";

        this.message2="hello,this is put into session!";

        this.message3="hello,this is put into request!";

        ActionContext  ac=ActionContext.getContext();

        //获取request级别的Map对象，把相关数据写入该对象中。

 ((Map<String ,Object>)ac.get("request")).put("message3", message3);

         //获取Application级别的Map对象，把相关数据写入该对象中。

          ac.getApplication().put("message", message);

        //获取sessiont级别的Map对象，把相关数据写入该对象中。

          ac.getSession().put("message2", message2);

        return SUCCESS;

}

package com.bochy.struts2.action;

import java.util.Map;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ApplicationAware;

import org.apache.struts2.interceptor.RequestAware;

import org.apache.struts2.interceptor.ServletRequestAware;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class Hello extends ActionSupport implements ServletRequestAware{

    /**

     *

     */

    private static final long serialVersionUID = 1L;

    private HttpServletRequest request;

    private HttpSession session;

    private ServletContext application;

    private String message;

    private String message3;

     public String getMessage3() {

        return message3;

    }

    public void setMessage3(String message3) {

        this.message3 = message3;

    }

    public String getMessage2() {

        return message2;

    }

    public void setMessage2(String message2) {

        this.message2 = message2;

    }

    private String message2;

    public String getMessage() {

        return message;

    }

    public void setMessage(String message) {

        this.message = message;

    }

    @Override

    public String execute() throws Exception {

        this.message="hello,this is put into application!";

        this.message2="hello,this is put into session!";

        this.message3="hello,this is put into request!";

          this.request.setAttribute("message3", message3);

          this.session.setAttribute("message2", message2);

          this.application.setAttribute("message", message);

        return SUCCESS;

    }

    @Override

    public void setServletRequest(HttpServletRequest request) {

        this.request=request;

        this.session=this.request.getSession();

        this.application=this.session.getServletContext();

    }

}

package com.bochy.struts2.action;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class Hello extends ActionSupport {

    private static final long serialVersionUID = 1L;

    private String message;

    private String message3;

     public String getMessage3() {

        return message3;

    }

    public void setMessage3(String message3) {

        this.message3 = message3;

    }

    public String getMessage2() {

        return message2;

    }

    public void setMessage2(String message2) {

        this.message2 = message2;

    }

    private String message2;

    public String getMessage() {

        return message;

    }

    public void setMessage(String message) {

        this.message = message;

    }

    @Override

    public String execute() throws Exception {

        this.message="hello,this is put into application!";

        this.message2="hello,this is put into session!";

        this.message3="hello,this is put into request!";

        //调用ServletActionContext的getServletContext()获取Application对象

          ServletContext application=ServletActionContext.getServletContext();

        //调用ServletActionContext的getRequest()获取request对象

          HttpServletRequest request=ServletActionContext.getRequest();

         //调用ServletActionContext.getPageContext().getSession()获取session对象

          HttpSession session=ServletActionContext.getPageContext().getSession();

         // HttpSession session=request.getSession();

         request.setAttribute("message3", message3);

          session.setAttribute("message2", message2);

          application.setAttribute("message", message);

        return SUCCESS;

    }

}