Postgresql 9.4 / JSONB / JDBC

Hello,

I'm new to this list, and have tried searching both the mailing list
archives, and internet in general, for information on how to use the new
JSONB data type with JDBC. Found almost nothing in the mailing list
archives, and internet searches "helpfully" assume I've misspelled "json"
and give me results that are unrelated or refer to the basic "JSON" type
from older Postgresql versions.

How can this type be used, with simple "flat" key-value collections (maps),
with tree-like maps-of-maps, and (ideally) with JSON APIs such as Jackson
JSON API?

Is it possible? Is it already described somewhere that I missed?

Thanks,
Christopher