public class AServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
			//1 獲得Application域中存放的統計數字
			Integer count = (Integer) getServletContext().getAttribute("count");
			//2 判斷是否獲得到統計數字
			if(count == null){
				//沒獲得到=> 將數字初始化為1
				count = 1;
			}else{
				//獲得到了=> 將數字加1
				count += 1;
			}
			//3 輸出,放回到Application域中
			response.getWriter().write("you are the "+ count+" vistors");
			getServletContext().setAttribute("count",count);
	}

}