Command Pattern in client-server context

I am trying to develop a client-server application. I want to integrate a Command-Pattern but i have never seen an example. My client have to loggin to the server then it requests some kinds of data like all the students stored in the database. Can someone show me an example(i mean code) in java of a Command-Pattern used in a client-server context? Who is the client, the invoker and reciver in this context? An example of how serializzation and deserializzaation of Commands works? How should my server answer to the client's requests?