How to accept socket while reading a DataInputStream?

Question

I have this java code,

ServerSocket server = new ServerSocket(4321);
        ArrayList<Socket> clients = new ArrayList<Socket>();
        ArrayList<DataInputStream> disC = new ArrayList<DataInputStream>();
        ArrayList<DataOutputStream> dosC = new ArrayList<DataOutputStream>();
        while(true){
            try{
                Socket socket = server.accept();
                DataInputStream dis = new DataInputStream(socket.getInputStream());
                DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
                clients.add(socket);
                disC.add(dis);
                dosC.add(dos);

                System.out.println(dis.readLine());

            }catch(Exception exc){
                exc.printStackTrace();
            }
        }

I want to accept a Socket while executing "dis.readLine()". Scenario: ClientA connect to the server. ClientB connect to the server. ClinetA sends message to server. ClientC connect to the server.

In my code above, It stop in "ClientB connect to the server".