The JSP implicit object ‘session’ is used to track user session between user requests.

Name Interface Tomcat Implementation
session javax.servlet.http.HttpSession org.apache.catalina.session.StandardSessionFacade

JSP implicit object ‘session’ example program (github)

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<!-- jsp implicit object request example -->
Tomcat implementation of jsp implicit object s : <% out.println(session.getClass().getCanonicalName()); %> <br/>
<!-- how to add an attribute to session -->
<%session.setAttribute("who", ""); %>
<!-- how to get an attribute from session -->
<%out.println(session.getAttribute("who"));%> <br/>
<!-- how to access servlet context using session object -->
<%session.getServletContext().setAttribute("attribute1", "attribute1Value"); %>
<%out.println(session.getServletContext().getAttribute("attribute1")); %>