How to take sever port from argv[] in java socket?

Question

I have this line of code in server.java file that create a sever and take the arge[0] as port but it show ArrayIndexOutOfBoundsException

//create a Server object
           Server server = new Server();
   
           //show GUI:
           server.pack();
           server.setVisible(true);
           server.setSize(new Dimension(400, 200));
   
           //get RTSP socket port from the command line
           int RTSPport = Integer.parseInt(argv[0]);
           server.RTSP_dest_port = RTSPport;
          
           //Initiate TCP connection with the client for the RTSP session
           ServerSocket listenSocket = new ServerSocket(RTSPport);
           server.RTSPsocket = listenSocket.accept();
           listenSocket.close();

The same thing goes for client.java file

//Create a Client object
           Client theClient = new Client();
           
           //get server RTSP port and IP address from the command line
           //------------------
           int RTSP_server_port = Integer.parseInt(argv[1]);
           String ServerHost = argv[0];
           theClient.ServerIPAddr = InetAddress.getByName(ServerHost);
   
           //get video filename to request:
           VideoFileName = argv[2];
   
           //Establish a TCP connection with the server to exchange RTSP messages
           //------------------
           theClient.RTSPsocket = new Socket(theClient.ServerIPAddr, RTSP_server_port);

I also try using Scanner and BufferedReader to get port from terminal but the client doesn't seem to connect to the server. Is there any other way?