Synchronizing peers in transfer over Socket

Question

Hi again!
I'm relatively new to Java, so there are many issues I still have to figure out ;-)
Here are two of them:
1) How can peers be synchronized in transfer over Socket? For example:
This is the receiving peer:
DataInputStream dsin = new DataInputStream(socket.getInputStream());
String s = dsin.readUTF();This is the sending peer:
DataOutputStream dsout = new DataOutputStream(socket.getOutputStream());
dsout.writeUTF("something...");
dsout.close();At the receiving peer in some cases the EOFException or SocketException (Socket closed) are raised. I suspect this happens either because the receiver tries to read input before it is fully transfered or when the sender already managed to close the socket's OutputStream.
So how can such a transfer be synchronized?
2) What if both peers close their socket's OutputStream? Does this result in closing the connection and releasing all its resources, such as port?
Thank you everyone!

Answer 1

this is what I learnt:Sorry, try again!
DO NOT close the Socket on any endpoint until you make sure that the other endpoint managed to call socket.getInputStream().This 'rule' is quite unnecessary.
According to the documentation, getInputStream() may return a stream which buffer was discarded by network software if a broken connection was detected.That's a complete misreading and misquoting of the documentation. A reset can happen to the connection at any time; can cause loss of data from te socket receive buffer; and has nothing to do with the operation of getting the input stream. Getting the input stream of a socket has nothing to do with the network or the state of the connection. It just constructs a Java object. So this rule is quite pointless.
Even more, it seems to be a good practice not to close the Socket until you are sure that the other endpoint will not try to read from the channel.You've got that back to front as well. THink about that some more and you will see it involves an infinite regression.
The only rules you need are these:
(a) don't close the socket until you're sure the other end has finished writing. You have to close the socket while the other end is still reading, so that it will get a EOS indication, so it will know you've gone away, so it will stop writing and close its end of the socket.
(b) closing the socket or either of its streams closes the other two items. You should always close the topmost output stream of a socket and nothing else.