TL;DR, I've been working on this alone, and thought I request some input from other engineers, software developers out there, that might know this stuff better than me.

I have come up with the following UML class diagram:

I don't know how to incorporate the Server class. Where would one put this?

Details:

getReceptionTime() : Returns a string indicating a timestamp when the Server received the actual message.

connect() : Sends a Message object to the Server.

Additionally: The user (client) must be able to,

1. Connect & Disconnect
2. Display a list of currently connected users
3. Send a new message
4. Display current messages in a list

EDIT: Why is this being Down Voted?

EDIT 2: Every communication with the Server happens through the ConnectionManager.