Allocating zero capacity ByteBuffer [closed]

Answer 1

This can be used to implement Null Object design pattern http://en.wikipedia.org/wiki/Null_Object_pattern, similar to Collections.emptyList and others, creates an immutable object that can be reused.

Answer 2

If you have a method that must return a ByteBuffer and returning null is inappropriate for whatever reason, but you have no data to return, then returning a zero-length ByteBuffer would satisfy those conditions.