ServletContext记录访问次数,三元运算符

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//创建对象
		ServletContext sc = getServletContext();
		//获取tongji的值,强转成Integer,可以接收null
		Integer tongji=(Integer)sc.getAttribute("tongji");
		//为null,说明是第一次访问
		if(tongji==null){
			tongji=1;
		}else{
			tongji++;
		}
		//把上面执行的结果,添加到ServletContext 中,完成一次记录
		sc.setAttribute("tongji", tongji);
		System.out.println("第"+sc.getAttribute("tongji")+"次访问");

	}

	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		ServletContext sc = getServletContext();
		Integer tongji=(Integer)sc.getAttribute("tongji");
		//三元运算符:两个数等于,则是":"左边,不等于则是":"右边
		//tongji==null则为0,不等于null则为tongji本身的数字
		System.out.println("累积访问次数:"+(tongji==null?0:tongji));

}