application

Application

对应的类 ServletContext

用于保存整个WebApplication的生命周期内都可以访问的数据

xx extends HttpServlet

ServletContext application = this.getServletContext();

//拿到所有客户端的内存

//包括 Servlet 的整个容器

ServletContext application = this.getServletContext();

Object objValue = (Object) application.getAttribute("paramName");

application.setAttribute(" paramName ",  objValue);