java socket programming

[Rohan Thakare]

i am having a file containg data for students name and their marks. i am sending this file from client to server using

Socket clientSocket = new Socket("127.0.0.1", portNo);
OutputStream os = clientSocket.getOutputStream();           
os.write(clientWriteArr,0,clientWriteArr.length);

and on server side reading the file contents using

ServerSocket sock = new ServerSocket(5432);
Socket serverSocket = sock.accept();
InputStream is = serverSocket.getInputStream();

i am modifyidng the file contents on server side
all the above thing are working fine.
now i want to send this file back to client using the same socket connection. but this thing is not working and i am not getting any exception.

[JavierL]

You need to open another connection, because you are sending in one way, one socket is waiting for input (and receiving), the other is sending.