Some general Java NIO questions

Networking & Multiplayer
#1

Hello,
today I have started with Java NIO, but it seems to be quite complex, hence I have some questions to which I couldn’t find any answer in those NIO tutorials I have read.

For learning purposes I want to implement some very common use cases:

  1. Sending serialized objects to a server, deserializing and storing them in a collection.
  2. Requesting data from a server. The data could be anything, maybe some objects in an array.

I don’t understand how ObjectInputStream/ObjectOutputStream and ByteBuffer work together and I’m not sure how many channels I need on the client and on the server. Do I need one socket channel on each side for each use case (4 socket channels altogether) or would one read-write-socket channel on each side be sufficient?

Thanks for all answers.