一、间接访问

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
     
      )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;}
     

二、直接访问（Ioc方式）

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();    }}

三、 直接访问

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;    }}