Struts 2对Servlet API进行了封装，是业务层更加独立，，如果需要调用Request、Response等Servlet API有两种途径
利用ServletActinContext的静态方法
Struts 2利用ServletActinContext来维护Servlet对象，ServletActinContext利用ThreadLocal来维护不同线程的Servlet对象，因此可以使用ServletActinContext来获得Servlet的各种对象
import org.apache.struts2. ServletActinContext;public class LoginActin extends ActionSupport{public String login(){HttpServletRequest request = ServletActinContext.getRequest();HttpServletResponse response = ServletActinContext.getResponse();HttpServletContext context = ServletActinContext.getServletContext();HttpSession session = request.getSession();……}}利用相关的Aware接口
Struts 2在实例化一个Action实例时，如果发现它实现了相关的Aware接口，会把相应的资源通过Aware接口方法注射进去，Aware接口其实是一种拦截器
Servlet API常用对象application、request、response、session对应的Aware接口分别为ServletContextAware、ServletRequestAware、ServletResponseAware、SessionAware
public class ServletAwareActionextends ActionSupport implementsServletContextAware,ServletRequestAware,ServletResponseAware,SessionAware{private HttpServletRequest request ;private HttpServletResponse response;private HttpServletContext application;private HttpSession session ;//相应的setter方法public void setServletRequest(HttpServletRequest request ){this.request = request;}public void setServletResponse(HttpServletResponse response ){this.reponse = reponse;}public void setServletContext(HttpServletContext application ){this. application = application;}public void setSession(Map sessionValues){this.session = sessionValues;}//然后可以在Action中直接使用这些对象public String execute(){request.getRemoteAddr();response.getContentType()session.get(“account”);return SUCCESS;}}
失败是成功的亲娘，没有失败哪来的成功呢?诺贝尔如果不经历千万次的失败，
