ChatRmiServer.java

package com.esotericsoftware.kryonet.examples.chatrmi;

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JLabel;

import com.esotericsoftware.kryonet.Connection;
import com.esotericsoftware.kryonet.Listener;
import com.esotericsoftware.kryonet.Server;
import com.esotericsoftware.kryonet.rmi.ObjectSpace;
import com.esotericsoftware.minlog.Log;

// This class is the server for a simple chat client/server example that uses RMI.
// It is recommended to review the non-RMI chat example first.
// While this example uses only RMI, RMI can be mixed with non-RMI KryoNet usage.
// RMI has more overhead (usually 4 bytes) then just sending an object.
public class ChatRmiServer {
	Server server;
	ArrayList<Player> players = new ArrayList();

	public ChatRmiServer () throws IOException {
		server = new Server() {
			protected Connection newConnection () {
				// Each connection represents a player and has fields
				// to store state and methods to perform actions.
				Player player = new Player();
				players.add(player);
				return player;
			}
		};

		// Register the classes that will be sent over the network.
		Network.register(server);

		server.addListener(new Listener() {
			public void disconnected (Connection connection) {
				Player player = (Player)connection;
				players.remove(player);
				if (player.name != null) {
					// Announce to everyone that someone (with a registered name) has left.
					String message = player.name + " disconnected.";
					for (Player p : players)
						p.frame.addMessage(message);
					updateNames();
				}
			}
		});
		server.bind(Network.port);
		server.start();

		// Open a window to provide an easy way to stop the server.
		JFrame frame = new JFrame("Chat RMI Server");
		frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		frame.addWindowListener(new WindowAdapter() {
			public void windowClosed (WindowEvent evt) {
				server.stop();
			}
		});
		frame.getContentPane().add(new JLabel("Close to stop the chat server."));
		frame.setSize(320, 200);
		frame.setLocationRelativeTo(null);
		frame.setVisible(true);
	}

	void updateNames () {
		// Collect the names of each player.
		ArrayList namesList = new ArrayList(players.size());
		for (Player player : players)
			if (player.name != null) namesList.add(player.name);
		// Set the names on everyone's chat frame.
		String[] names = (String[])namesList.toArray(new String[namesList.size()]);
		for (Player player : players)
			player.frame.setNames(names);
	}

	class Player extends Connection implements IPlayer {
		IChatFrame frame;
		String name;

		public Player () {
			// Each connection has an ObjectSpace containing the Player.
			// This allows the other end of the connection to call methods on the Player.
			new ObjectSpace(this).register(Network.PLAYER, this);
			// Get the ChatFrame on the other end of the connection.
			// This allows the server to call methods on the client.
			frame = ObjectSpace.getRemoteObject(this, Network.CHAT_FRAME, IChatFrame.class);
		}

		public void registerName (String name) {
			// Do nothing if the player already registered a name.
			if (this.name != null) return;
			// Do nothing if the name is invalid.
			if (name == null) return;
			name = name.trim();
			if (name.length() == 0) return;
			// Store the player's name.
			this.name = name;
			// Add a "connected" message to everyone's chat frame, except the new player.
			String message = name + " connected.";
			for (Player player : players)
				if (player != this) player.frame.addMessage(message);
			// Set the names on everyone's chat frame.
			updateNames();
		}

		public void sendMessage (String message) {
			// Do nothing if a player tries to chat before registering a name.
			if (this.name == null) return;
			// Do nothing if the chat message is invalid.
			if (message == null) return;
			message = message.trim();
			if (message.length() == 0) return;
			// Prepend the player's name and add to everyone's chat frame.
			message = this.name + ": " + message;
			for (Player player : players)
				player.frame.addMessage(message);
		}
	}

	public static void main (String[] args) throws IOException {
		Log.set(Log.LEVEL_DEBUG);
		new ChatRmiServer();
	}
}