在struts2的action中操作域对象(request、session)

在struts2的Action中，操作域对象一共有三种方式：
1.ActionContext(与servelt API无关联):

 //相当于request
 ActionContext.getContext().put("userName", user.getUserName());
 //相当于session
 ActionContext.getContext().getSession().put("userName", user.getUserName());
 //相当于Application
 ActionContext.getContext().getApplication().put("userName", user.getUserName());
 //parameter
 String name = (String) ActionContext.getContext().getParameters().get("userName");

2.实现ServletRequestAware,ServletResponseAware接口，通过注入的方式，获取request、response:

 private HttpServletResponse response;

 private HttpServletRequest request;

 @Override
 public void setServletResponse(HttpServletResponse response) {
 this.response = response;
 }

 @Override
 public void setServletRequest(HttpServletRequest request) {
 this.request = request;
 }

3.通过ServletActionContext提供的静态方法获得request、response:

 HttpServletRequest request = ServletActionContext.getRequest();