How to use session in Java web Project

Creating / Using session : Java Web Project

// NameSpace imports

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;

/* Use openSymphony .jar for above import

//Declaration of Session

private Map session;

//Create setter getter

session = ActionContext.getContext().getSession();

//Use session.put & session.get

session.put(“Id”,userID );

String userId = (String)session.get(“Id”);