How can i create a 2D vector??

Question

Hi,
I am doing a client-server application which is simliar to ICQ.
And now i want to create a 2D vector.
i tried:
Vector [] [] v=new Vector();but it doesn't work, i want to place the loginID and IP address of clients into a vector and send this vector as an object to all clients. In the client application, i will make use of this vector to construct an online list by using JList.
could somebody please give me some ideas??thanks!

Answer 1

hi,
i still have some problems!!
could you help me??
thanks in advance!
in the server application,
once a user connects to the server, his ID and IPAddress will be passed into the Users(InetAddress ip, String userid) constructor!!! An object will then be created and i put it into an ArrayList. I want to send the ArrayList using ObjectOutputStream. There was no problem when I complied the server application.
Socket s=null;
ArrayList ServerOnlinelist=new ArrayList();
Users aUser=new User(socket.getInetAddress(),loginid);
ServerOnlinelist.add(aUser);
ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
oos.write(aUser);
oos.flush();
oos.close();
s.close();
class Users {   
        private final InetAddress ip;  
        private final String userId;   
        public Users(InetAddress ip, String userId) {       
            this.ip = ip;       
            this.userId = userId;    }
    }However, in the client application, it can't receive the ArrayList object sent by the server application.
What's wrong with my codes??
Socket socket=null;
  ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
                     SMI.OnlineList=(ArrayList)ois.readObject();
                     System.out.println(SMI.OnlineList.toString());
                      ois.close();
socket.close();
............................................the following error msgs were from the client application( when i tried to connect to the server):
http://hk.geocities.com/iamsupersuperman/AAA.JPG