how to pass object among multiple classes in web application context

It's an extended question based on the post below. How to pass an object between multiple classes? Java

Is there a better way when I have many classes need to change the object. Passing the object to each of them can be messy. Also in the web application, is it possible to use some kind of Singleton pattern at session level so that every class just access the object through the session level Singleton instance?