struts2如何获取Request-Session-ServletContext-Response

1. 访问和添加request/session/application属性
   如果只是往request/session/application中设置属性，可以用下面的方式
   

  ActionContext ctx = ActionContext.getContext();
		ctx.getApplication().put("app", "应用范围");//往ServletContext里放入app
		ctx.getSession().put("ses", "session范围");//往session里放入ses
		ctx.put("req", "request范围");//往request里放入req
		ctx.put("names", Arrays.asList("老张", "老黎", "老方"));
   

  jsp页面上获取方式
  

 ${applicationScope.app}<br>
    ${sessionScope.ses}<br>
    ${requestScope.req}<br>

2. struts2中如何获取httpServletRequest/HttpSession/ServletContext/HttpServletResponse对象
方法一，通过ServletActionContext类获取：(推介使用)
  

  public String rsa() throws Exception{
		HttpServletRequest request = ServletActionContext.getRequest();
		ServletContext servletContext = ServletActionContext.getServletContext();
		request.setAttribute("req", "请求范围属性");
		request.getSession().setAttribute("ses", "会话范围属性");
		servletContext.setAttribute("app", "应用范围属性");
		HttpServletResponse response = ServletActionContext.getResponse();
		return "message";
	}

方法二，实现指定接口，由struts框架注入：

import com.opensymphony.xwork2.ActionContext;
public class HelloWorldAction2 implements ServletContextAware,ServletRequestAware,ServletResponseAware{
	private HttpServletRequest request ;
	private HttpServletResponse response ;
	private ServletContext servletContext ;
	public void setServletContext(ServletContext context) {
	//context对象不是应用程序传进去的，而是由struts框架自动注入的
		this.servletContext = context ;
	}
	public void setServletRequest(HttpServletRequest request) {
		this.request = request ;
	}
	public void setServletResponse(HttpServletResponse response) {
		this.response = response ;
	}
}