struts2获取request,session,application4种方式

第一种，依赖容器获取：

private Map request;
private Map session;
private Map application;
public ActionTest()
{
request=(Map)ActionContext.getContext().get("request");
session=ActionContext.getContext().getSession();
application=ActionContext.getContext().getApplication();
}

第二种，IoC方式，是通过依赖注入方式获取到对象，需要实现相应的接口为 RequestAware,SessionAware,ApplicationAware：

private Map<String,Object> request;
private Map<String,Object> session;
private Map<String,Object> application;

public void setRequest(Map<String, Object> request) {
this.request = request;
}

public void setSession(Map<String, Object> session) {
this.session = session;
}

public void setApplication(Map<String, Object> application) {
this.application = application;
}

第三种，获取的是原型：

private HttpServletRequest request;
private HttpSession session;
private ServletContext application;

public ActionTest()
{
request=ServletActionContext.getRequest();
session=request.getSession();
application=session.getServletContext();
}

第四种，通过IoC获取原型，需要实现ServletRequestAware，并且要实现setServletRequest方法：

private HttpServletRequest request;
private HttpSession session;
private ServletContext application;

public void setServletRequest(HttpServletRequest request)
{
this.request=request;
this.session=request.getSession();
this.application=session.getServletContext();
}