Thread: Sending and Receiving Via Tcp And Udp

Originally Posted by amit1983

I want to to implement Sending and Receiving data (messages) via socket connectionד (TCP and UDP).

Ok, but remember that TCP and UDP communications are very different, both at technical level (different Java classes) and conceptual level (TCP establishes a (potentially long) communication while UDP handles single, distinct and (potentially) unrelated packets).

Originally Posted by amit1983

I want to use the same interface for the Sending and Receiving .

If you mean to maintain, for both TCP and UDP, the same data classes for objects to send/receive, it's surely possible.

Originally Posted by amit1983

I want to allocate all the necessary classes and variables at the initialization (and not at run time).

What do you exactly mean?

Originally Posted by amit1983

1. if I send the messages via ObjectOutputStream.writeObject it will send more bytes than the size of the class CTestMsgextends ? (because it Serializable) ?

Yes, serialization has its specific "protocol", that contains more informations than the single pure fields of an object to write.

Originally Posted by amit1983

2. Can you recommend me (another way, not via Serializable) on how to implement my needs ?

There's not an easy answer. It depends on your requirements. Are you developing both ends of the communication? (so you can choose/invent your standard)

Originally Posted by amit1983

1. when I wrote: "I want to allocate all the necessary classes and variables at the initialization (and not at run time)." I meant that I cant (don't want to do something like:
byte[] data = new byte[len];
in the middle of the run time (I can allocate memory just in the start up (using pools))

So you want to use and re-use one (or more) byte[] buffer(s), isn't it? If the size is sufficient for your datas, technically it is surely possible. If it has sense .... depends on what/how you want to send/receive.

Originally Posted by amit1983

2. Just to be sure, if I will use serialization and send structure to an application which was written in c++, then the other application (in c++) will have problem to read the data (because it expect for structure with known fields, and not for a new message (serialize message),
am I write ?

Networking, in general, is based on well defined protocols and standards. Two systems that communicate to each other must "speak" the same protocol/standard. If you develop only one end and the other is already existent (or will be developed by other developers), you must know or agree the communication protocol.
Without these premises we can sit here and argue until the next year.

Originally Posted by amit1983

3. If I have a structure which I need to send (via UDP or TCP),
what is the best way too send it ?

There's no "best" way, said in general. It depends on (just a few points that come to mind):
- how the data structure is made
- which data types contains
- what are the systems (and programming languages) involved
- if the communication is unidirectional or bidirectional
- if bidirectional, if it's synchronous or asynchronous