chat-server

public class User {
	private MessageManager contactManager;
	private MessageManager messageManager;

	public construct(contactManager, messageManager)
		this.contactManager = contactManager;
		this.messageManager = messageManager;
	}


	public void sendMessage(String nameContact, String message) {
		this.message_manager.sendMessage();

	}

	public Contact getContact(int id) {
		Contact contact = this.contactManager(id);
		return contact;
	}
}


public class BestYMessageManager implements ContactManager {

}
public interface MessageManager {
	void sendMessage();
	void reciveMessage();

}

public class FastXManagerContacts implements MessageManager {

}

public interface ConctactManager {
    showContact();
	shotAllContacts();
	addContact();
	removeContact();
	editContact();
	findContact();
}


public class Contact {
	private String name;
	private String status;
} 

public class Login implements   {
	public String authenticate(String user, String password);
}

public interface authentication {
	authenticate();
}

skeleton of chat-server program