static void handleTCP(Socket clientSocket) throws IOException {
        //get socket
        Socket connectionSocket = clientSocket;
        //input stream from client
        BufferedReader inFromClient = new BufferedReader(
                new InputStreamReader(connectionSocket.getInputStream()));
        //output stream to client
        DataOutputStream outToClient = new DataOutputStream(
                connectionSocket.getOutputStream());
        //message received from the client
        clientString = inFromClient.readLine() + "\n";
        System.out.println(connectionSocket.getInetAddress().toString() + ":" + connectionSocket.getPort() + " sent this message: " + clientString);
        //sent the modified message to client
        outToClient.writeBytes(clientString);
    }