Getting current session object in Java

Can I access session object from within a function where request object is not present?

I know in Java we access session like this:

HttpSession session = request.getSession(true);

But what if we want to access session when request object is not present?

Is it possible? is there an alternate way to get session object?

Edit

I have a servlet

public class ABC extends HttpServlet
{
    public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException
    {
             ..........
             ...........
        myFun1(x,y,z);  
    }

      private void myFun1(int x, int y,long z)
      {
            .........
            myFun2(a,b);    
       }

      private void myFun2(int a,String b)
      {
            .........

            //      Need Session here
       }

}