Android Reading From Socket Hangs On Second Read Loop

I got to implement a chat in my application. Connection to a server is made using sockets. I should register to that server and the server will aknowledge that with a reply. I have

Solution 1:

The amount of data to be sent/received over a socket based connection is protocol dependend and not known to the TCP/IP stack, but only to the application layer.

The protocol used is developer dependend ... ;-) so coming to your questions:

If I should read only the bytes I am supposed to read, does that mean that I either have to:

• Know in advance the length of the server response?

Yes, this is one possibility.

• or make the server send a code to notify it has finished to send its response?

Also yes, as this is another possibility. Common markers are \n or \r\n. The NUL/'\0' character also might make sense.

A third option is to prefix each data chunk with a constant number of bytes describing the amount of bytes to come.

Solution 2:

Instead of dealing with bytes, maybe it's simpler handling instances of ad-hoc classes, like - for instance - a Message class:

The server:

// StreamsprotectedObjectInputStreamfromBuffer=null;
protectedObjectOutputStreamtoBuffer=null;

// Listening for a new connectionServerSocketserverConn=newServerSocket(TCP_PORT);
socket = serverConn.accept();
toBuffer = newObjectOutputStream(socket.getOutputStream());
fromBuffer = newObjectInputStream(socket.getInputStream());

// Receiving a new Message objectMessagedata= (Message)fromBuffer.readObject();

The client then sends a message by simply:

// Sending a messageMessagedata=newMessage("Hello");
toBuffer.writeObject(data);

Message can be as complex as needed as long as its members implement Serializable interface.