Basic question before I get too far into coding. I was told once that in order for the Android Phone to contact a PC server, that server must be written in Java. I find this a little convoluted, but is this the case? Or by using the TCP/IP classes (Socket), can I just read and write binary data over the pipe regardless of who or how the server was written?
TCP/IP is language agnostic, you can create a client/server implementation in any language or platform that supports TCP/IP and communicate with any other TCP/IP connection.
The communication over the protocol is dependent on implementation though so you need to make sure that both client and server implementations understand the communication going over the sockets.