How to properly close a socket?

Question

Java

Client:
Open socket: Write data:
Socket socket = new Socket(host,port);

socket.getOutputStream().write("str");
socket.getOutputStream().flush();

Read data:
response = socket.getInputStream().read();
Close connection and socket:

socket.shutdownInput();
socket.shutdownOutput();
socket.close();

Server:

Socket clientSocket = serverSocket.accept();
message = clientSocket.getInputStream().read();
clientSocket.getOutputStream().write("str2");

In this case, clientSocket.isConnected() is true, and the server does not see that the client has disconnected. How can I track if a client has disconnected?

Answer 1

Can be read from inputstream. As soon as you get back a void (an empty string, ''), then this means that the client has disconnected (this is for blocking sockets).
On non-blocking sockets, you need to react to the signal.