Servlet中怎么取得session和application

import java.io.IOException;

import java.io.PrintWriter;

 

import javax.servlet.ServletContext;//和其它的不在一个包

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

 

 

public class X extends HttpServlet {

 

 

 public void doGet(HttpServletRequest request, HttpServletResponse response)

   throws ServletException, IOException {

            HttpSession session=request.getSession();//得到session

         ServletContext    application =super.getServletContext();//GenericServlet提供的方法，得到application

 }