Why Java?

Object oriented. Naturally modular.
Understands TCP/IP.
High level of platform independance (but not perfect).
Originally designed--and still intended--as an embedded systems language.

Why Not?

Slow.
Single owner.

Using Java, we can implement jCIFS in small modular bits. Something as basic and pervasive as a NetBIOS name can be encapsulated. The objects can be identified and their characteristics understood. This also facilitates porting to other languages.

Java bytecode processing is considered slow compared to fully compiled languages. This appears to be changing somewhat.