coarse-grained objects

[Anonymous]

Could someone please provide a definition/explanation of a coarse-grained object as opposed to a fine-grained one? I have a general understanding of the term, but not enough understanding to be able to explain them myself. Thanks

[Frank Carver]

"Java Tom",
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Thanks.

This name is obviously a pseudonym, and will be turnd off soon, so please choose a new name immediately.

[Tom Obermeyer]

Done.

[Frank Carver]

Many thanks. We do appreciate people sticking to our site guidelines.

[Paul Caswell]

 

Originally posted by Java Tom:
Could someone please provide a definition/explanation of a coarse-grained object as opposed to a fine-grained one? I have a general understanding of the term, but not enough understanding to be able to explain them myself. Thanks

Good question. I am also interested in any consensus on the answer.
I will share my current understanding and my personal way of explaining this:
Fine-grained objects are building blocks which traditionally we programmers have glued together at compile-time. They have visibility to the programmers and these objects can be viewed as 'how' we build a component. (in C++ I used to say that they disappeared at compile time - not quite true in Java).
Course-grained objects (e.g. components, applications, libraries) are constructed from many fine-grained objects. These course-grained objects are more commonly glued together at run-time (late-binding). They are often the output of a development process not the input. They have system level visibility, well defined interfaces and can be considered a unit of delivery/deployment. From programmers perspective they can be viewed as �what� is being developed vs �how�.

[Tom Obermeyer]

Thanks Paul. I left my question broad, but I was really pondering the incorporation of the concept of coarse-grained objects with regards to Enterprise JavaBeans design and development. How would you go about developing coarse-grained EJBs from object models that model "fine-grained" objects? It seems like a coarse-grained object would have the properties and behaviors of several objects in the model. At what point would your EJB be to "coarse?"