Fix client connection with the proxy

client/src/main/java/fr/insa/clavardator/client/network/NetDiscoverer.java

@@ -5,7 +5,10 @@ import fr.insa.clavardator.lib.util.Log;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
-import java.net.*;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
 
 import static fr.insa.clavardator.client.network.NetUtil.isLocalAddress;
 
@@ -104,16 +107,22 @@ public class NetDiscoverer {
 		@Override
 		public void run() {
 			byte[] buf = broadcastMessage.getBytes();
+			DatagramSocket broadcastSocket = null;
 			try {
 				for (InetAddress broadcastAddr : NetUtil.listAllBroadcastAddresses()) {
-					DatagramSocket broadcastSocket = new DatagramSocket();
+					broadcastSocket = new DatagramSocket();
 					broadcastSocket.setBroadcast(true);
 					broadcastSocket.send(new DatagramPacket(buf, buf.length, broadcastAddr, DISCOVERY_PORT));
 					Log.v(this.getClass().getSimpleName(), "Broadcast sent on address " + broadcastAddr.toString());
+					broadcastSocket.close();
 				}
 			} catch (IOException e) {
 				Log.e(this.getClass().getSimpleName(), "Error sending broadcast", e);
 				errorCallback.onError(e);
+			} finally {
+				if (broadcastSocket != null) {
+					broadcastSocket.close();
+				}
 			}
 		}
 	}
@@ -138,15 +147,11 @@ public class NetDiscoverer {
 		@Override
 		public void run() {
 			try {
+				socket = new DatagramSocket(DISCOVERY_PORT);
+				byte[] buffer = new byte[BROADCAST_BUFFER_SIZE];
+
 				while (!shouldStop) {
-					socket = new DatagramSocket(null);
-					socket.setOption(StandardSocketOptions.SO_REUSEPORT, true);
-					socket.setOption(StandardSocketOptions.SO_REUSEADDR, true);
-					socket.bind(new InetSocketAddress((InetAddress) null, DISCOVERY_PORT));
-
-					byte[] buffer = new byte[BROADCAST_BUFFER_SIZE];
 					DatagramPacket receivedPacket = new DatagramPacket(buffer, BROADCAST_BUFFER_SIZE);
-
 					socket.receive(receivedPacket);
 					Log.v(this.getClass().getSimpleName(), "Broadcast received from ip " + receivedPacket.getAddress().toString());
 					callback.onBroadcastReceived(receivedPacket.getAddress(), new String(receivedPacket.getData()));
@@ -156,6 +161,9 @@ public class NetDiscoverer {
 					Log.e(this.getClass().getSimpleName(), "Error receiving broadcast message", e);
 					errorCallback.onError(e);
 				}
+			} finally {
+				if (socket != null)
+					socket.close();
 			}
 		}
 
@@ -186,8 +194,7 @@ public class NetDiscoverer {
 		@Override
 		public void run() {
 			byte[] buf = message.getBytes();
-			try {
+			try (DatagramSocket responseSocket = new DatagramSocket()) {
-				DatagramSocket responseSocket = new DatagramSocket();
 				responseSocket.send(new DatagramPacket(buf, buf.length, address, RESPONSE_PORT));
 				Log.v(this.getClass().getSimpleName(), "Broadcast response sent to ip " + address.toString());
 			} catch (IOException e) {
@@ -217,12 +224,8 @@ public class NetDiscoverer {
 		@Override
 		public void run() {
 			try {
+				socket = new DatagramSocket(RESPONSE_PORT);
 				while (!shouldStop) {
-					socket = new DatagramSocket(null);
-					socket.setOption(StandardSocketOptions.SO_REUSEPORT, true);
-					socket.setOption(StandardSocketOptions.SO_REUSEADDR, true);
-					socket.bind(new InetSocketAddress((InetAddress) null, RESPONSE_PORT));
-
 					byte[] buffer = new byte[RESPONSE_BUFFER_SIZE];
 					DatagramPacket receivedPacket = new DatagramPacket(buffer, RESPONSE_BUFFER_SIZE);
 					socket.receive(receivedPacket);

client/src/main/java/fr/insa/clavardator/client/network/PeerHandshake.java

@@ -71,7 +71,9 @@ public class PeerHandshake {
 
 	private void sendUsernameTaken(TcpConnection thisConnection) {
 		Log.v(this.getClass().getSimpleName(), "Received username request using current username");
-		thisConnection.send(new UsernameTakenException("Username taken", userInformation.id), this::closeConnection, null);
+		UsernameTakenException exception = new UsernameTakenException("Username taken",
+				CurrentUser.getInstance().getId(), userInformation.id);
+		thisConnection.send(exception, this::closeConnection, null);
 	}
 
 

client/src/main/java/fr/insa/clavardator/client/server/InsaPresence.java

@@ -34,23 +34,20 @@ public class InsaPresence implements Presence {
 
 	private final String path;
 	private final int presencePort;
-	private final int proxyPort;
-
 	private TcpConnection presenceConnection;
-	private TcpConnection proxyConnection;
+	private final Proxy proxy;
-
 
 	public InsaPresence(String path, int presencePort, int proxyPort) {
 		this.path = path;
 		this.presencePort = presencePort;
-		this.proxyPort = proxyPort;
+		this.proxy = new Proxy(path, proxyPort);
 	}
 
 	@Override
 	public void subscribe(ParametrizedCallback<ArrayList<UserInformation>> callback, ErrorCallback errorCallback) {
 		if (!isConnected()) {
 			connectToPresence(
-					() -> connectToProxy(() -> {
+					() -> proxy.connect(() -> {
 						sendSubscribeMessage(errorCallback);
 						receiveSubscribeNotifications(callback, errorCallback);
 					}, errorCallback),
@@ -130,26 +127,6 @@ public class InsaPresence implements Presence {
 		}
 	}
 
-	/**
-	 * Connects to the presence proxy by TCP
-	 *
-	 * @param callback      Called when connection is successful
-	 * @param errorCallback Called on connection error
-	 */
-	private void connectToProxy(SimpleCallback callback, ErrorCallback errorCallback) {
-		try {
-			proxyConnection = new TcpConnection(InetAddress.getByName(path), proxyPort,
-					(newConnection) -> newConnection.send(new UserInformation(CurrentUser.getInstance()), () -> {
-						if (callback != null) {
-							callback.call();
-						}
-					}, errorCallback),
-					errorCallback);
-		} catch (UnknownHostException e) {
-			Log.e(getClass().getSimpleName(), "Could not connect to presence proxy", e);
-		}
-	}
-
 	/**
 	 * Closes the given connection
 	 */
@@ -167,8 +144,7 @@ public class InsaPresence implements Presence {
 	private boolean isConnected() {
 		return presenceConnection != null &&
 				presenceConnection.isOpen() &&
-				proxyConnection != null &&
+				proxy.isConnected();
-				proxyConnection.isOpen();
 	}
 
 	/**
@@ -177,13 +153,12 @@ public class InsaPresence implements Presence {
 	private void disconnect() {
 		Log.v(this.getClass().getSimpleName(), "Disconnecting presence server");
 		closeConnection(presenceConnection);
-		closeConnection(proxyConnection);
 		presenceConnection = null;
-		proxyConnection = null;
+		proxy.close();
 	}
 
 	@Override
-	public TcpConnection getProxyConnection() {
+	public Proxy getProxy() {
-		return proxyConnection;
+		return proxy;
 	}
 }

client/src/main/java/fr/insa/clavardator/client/server/Presence.java

@@ -1,6 +1,5 @@
 package fr.insa.clavardator.client.server;
 
-import fr.insa.clavardator.lib.network.TcpConnection;
 import fr.insa.clavardator.lib.users.UserInformation;
 import fr.insa.clavardator.lib.util.ErrorCallback;
 import fr.insa.clavardator.lib.util.ParametrizedCallback;
@@ -36,12 +35,12 @@ public interface Presence {
 	void unsubscribe(SimpleCallback callback, @Nullable ErrorCallback errorCallback);
 
 	/**
-	 * Gets a connection to the proxy.
+	 * Gets the proxy.
 	 * This can be used to initialize a
 	 * {@link fr.insa.clavardator.client.users.PeerUser Peeruser}
 	 * and send messages like on a local network.
 	 *
-	 * @return The server address
+	 * @return The proxy
 	 */
-	TcpConnection getProxyConnection();
+	Proxy getProxy();
 }

client/src/main/java/fr/insa/clavardator/client/server/Proxy.java

@@ -0,0 +1,86 @@
+package fr.insa.clavardator.client.server;
+
+import fr.insa.clavardator.client.users.CurrentUser;
+import fr.insa.clavardator.lib.message.SenderInfo;
+import fr.insa.clavardator.lib.network.TcpConnection;
+import fr.insa.clavardator.lib.users.UserInformation;
+import fr.insa.clavardator.lib.util.ErrorCallback;
+import fr.insa.clavardator.lib.util.Log;
+import fr.insa.clavardator.lib.util.SimpleCallback;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class Proxy {
+	private final String path;
+	private final int proxyPort;
+	TcpConnection proxyConnection;
+	Map<String, TcpConnection.MessageReceivedCallback> callbackMap = new HashMap<>();
+	private boolean receiving = false;
+
+	public Proxy(String path, int proxyPort) {
+		this.path = path;
+		this.proxyPort = proxyPort;
+	}
+
+	public void connect(SimpleCallback callback, ErrorCallback errorCallback) {
+		try {
+			proxyConnection = new TcpConnection(InetAddress.getByName(path), proxyPort,
+					(newConnection) -> newConnection.send(new UserInformation(CurrentUser.getInstance()), () -> {
+						if (callback != null) {
+							callback.call();
+						}
+					}, errorCallback),
+					errorCallback);
+		} catch (UnknownHostException e) {
+			Log.e(getClass().getSimpleName(), "Could not connect to the proxy", e);
+		}
+	}
+
+	public void send(Serializable message, @Nullable SimpleCallback callback, @Nullable ErrorCallback errorCallback) {
+		proxyConnection.send(message, callback, errorCallback);
+	}
+
+	public void receive(String userId, TcpConnection.MessageReceivedCallback callback, ErrorCallback errorCallback) {
+		Log.v(getClass().getSimpleName(), "Registering a new receive request from " + userId);
+		callbackMap.put(userId, callback);
+		if (!receiving) {
+			proxyConnection.receive(this::onMessageReceived, errorCallback);
+			receiving = true;
+		}
+	}
+
+	private void onMessageReceived(Object msg) throws IOException {
+		if (msg instanceof SenderInfo) {
+			TcpConnection.MessageReceivedCallback callback = callbackMap.get(((SenderInfo) msg).getSenderId());
+			if (callback != null) {
+				callback.onMessageReceived(msg);
+			} else {
+				Log.w(getClass().getSimpleName(),
+						"Nobody is waiting for messages from " + ((SenderInfo) msg).getSenderId());
+			}
+		} else {
+			Log.e(getClass().getSimpleName(),
+					"Proxy sent a message that does not contain sender information: " +
+							msg.getClass().getSimpleName());
+		}
+	}
+
+	public boolean isConnected() {
+		return proxyConnection != null &&
+				proxyConnection.isOpen();
+	}
+
+	public void close() {
+		proxyConnection.close();
+	}
+
+	public void disconnectUser(String id) {
+		callbackMap.remove(id);
+	}
+}

client/src/main/java/fr/insa/clavardator/client/ui/MainController.java

@@ -287,12 +287,12 @@ public class MainController implements Initializable {
 		if (presenceServer != null && online) {
 			presenceServer.subscribe(
 					param -> userList.onReceivePresenceNotification(
-									param,
+							param,
-									presenceServer.getProxyConnection()),
+							presenceServer.getProxy()),
 					(e) -> Log.v(
-									getClass().getSimpleName(),
+							getClass().getSimpleName(),
-									"Error subscribing to presence server",
+							"Error subscribing to presence server",
-									e));
+							e));
 		}
 	}
 

client/src/main/java/fr/insa/clavardator/client/users/DirectPeerConnection.java

@@ -0,0 +1,52 @@
+package fr.insa.clavardator.client.users;
+
+import fr.insa.clavardator.lib.network.TcpConnection;
+import fr.insa.clavardator.lib.util.ErrorCallback;
+import fr.insa.clavardator.lib.util.Log;
+import fr.insa.clavardator.lib.util.SimpleCallback;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.EOFException;
+import java.io.Serializable;
+
+public class DirectPeerConnection extends PeerConnection {
+	private final TcpConnection connection;
+
+	public DirectPeerConnection(TcpConnection connection, PeerUser user) {
+		super(user);
+		this.connection = connection;
+	}
+
+	@Override
+	protected void send(Serializable message, SimpleCallback callback, @Nullable ErrorCallback errorCallback) {
+		connection.send(message, callback, errorCallback);
+	}
+
+
+	@Override
+	protected void receive(TcpConnection.MessageReceivedCallback callback, ErrorCallback errorCallback) {
+		connection.receive(callback,
+				e -> {
+					disconnect();
+					if (!(e instanceof EOFException)) {
+						Log.e(this.getClass().getSimpleName(), "Error receiving message from " + user.getId(), e);
+						errorCallback.onError(e);
+					}
+				});
+	}
+
+
+	/**
+	 * Close the connection to this user
+	 */
+	private void closeConnection() {
+		if (connection != null && connection.isOpen()) {
+			connection.close();
+		}
+	}
+
+	@Override
+	public void disconnect() {
+		closeConnection();
+	}
+}

client/src/main/java/fr/insa/clavardator/client/users/PeerConnection.java

@@ -0,0 +1,34 @@
+package fr.insa.clavardator.client.users;
+
+import fr.insa.clavardator.lib.network.TcpConnection;
+import fr.insa.clavardator.lib.util.ErrorCallback;
+import fr.insa.clavardator.lib.util.SimpleCallback;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.Serializable;
+
+public abstract class PeerConnection {
+	protected final PeerUser user;
+
+	protected PeerConnection(PeerUser user) {
+		this.user = user;
+	}
+
+	protected abstract void send(Serializable message, SimpleCallback calback, @Nullable ErrorCallback errorCallback);
+
+	/**
+	 * Subscribe to this user messages.
+	 * If receiving new user info, update this user.
+	 * If receiving text message, store it in the history.
+	 *
+	 * @param errorCallback Callback on error
+	 */
+	protected abstract void receive(TcpConnection.MessageReceivedCallback callback, ErrorCallback errorCallback);
+
+	/**
+	 * Close the connection and set state to disconnected
+	 */
+	public abstract void disconnect();
+
+
+}

client/src/main/java/fr/insa/clavardator/client/users/PeerUser.java

@@ -2,6 +2,7 @@ package fr.insa.clavardator.client.users;
 
 import fr.insa.clavardator.client.chat.ChatHistory;
 import fr.insa.clavardator.client.db.DatabaseController;
+import fr.insa.clavardator.client.server.Proxy;
 import fr.insa.clavardator.lib.errors.UsernameTakenException;
 import fr.insa.clavardator.lib.message.FileMessage;
 import fr.insa.clavardator.lib.message.Message;
@@ -14,15 +15,14 @@ import fr.insa.clavardator.lib.util.Log;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.io.EOFException;
 import java.io.File;
 import java.io.IOException;
 import java.util.Date;
 
 public class PeerUser extends User implements Comparable<PeerUser> {
-	protected transient ChatHistory history;
+	private final transient ChatHistory history;
 	private UserState state = UserState.DISCONNECTED;
-	private transient TcpConnection connection;
+	private PeerConnection connection;
 
 	public PeerUser(String id, String username) {
 		super(id, username);
@@ -34,6 +34,23 @@ public class PeerUser extends User implements Comparable<PeerUser> {
 		history = new ChatHistory(this);
 	}
 
+	private void init(String id, String username, ErrorCallback errorCallback) {
+		setId(id);
+		setUsername(username);
+		setState(UserState.CONNECTED);
+		connection.receive(msg -> onMessageReceived(msg, errorCallback), errorCallback);
+	}
+
+	public void init(TcpConnection tcpConnection, String id, String username, ErrorCallback errorCallback) {
+		connection = new DirectPeerConnection(tcpConnection, this);
+		init(id, username, errorCallback);
+	}
+
+	public void init(Proxy proxy, String id, String username, ErrorCallback errorCallback) {
+		connection = new ProxyPeerConnection(proxy, this);
+		init(id, username, errorCallback);
+	}
+
 
 	/**
 	 * Sends a basic text message to this user
@@ -44,14 +61,15 @@ public class PeerUser extends User implements Comparable<PeerUser> {
 	public void sendTextMessage(String msg, @Nullable ErrorCallback errorCallback) {
 		if (connection != null) {
 			Log.v(this.getClass().getSimpleName(),
-					"Sending message to " + this.getUsername() + " / " + this.getId() + ": " + msg);
+					"Sending message to " + getUsername() + " / " + getId() + ": " + msg);
 			final Message message = new Message(CurrentUser.getInstance(), this, new Date(), msg);
-			connection.send(message, () -> history.addMessage(message, errorCallback), errorCallback);
+			connection.send(message, () -> addMessageToHistory(message, errorCallback), errorCallback);
 		} else {
 			Log.e(this.getClass().getSimpleName(), "Could not send message: connection is not initialized");
 		}
 	}
 
+
 	/**
 	 * Sends a message containing a file to this user
 	 *
@@ -65,7 +83,7 @@ public class PeerUser extends User implements Comparable<PeerUser> {
 			try {
 				final FileMessage message = new FileMessage(CurrentUser.getInstance(), this, new Date(), msg, file.getPath());
 				message.storeFile();
-				connection.send(message, () -> history.addMessage(message, errorCallback), errorCallback);
+				connection.send(message, () -> addMessageToHistory(message, errorCallback), errorCallback);
 			} catch (IOException e) {
 				Log.e(this.getClass().getSimpleName(), "Could not send message: error while opening file", e);
 				if (errorCallback != null) {
@@ -87,102 +105,61 @@ public class PeerUser extends User implements Comparable<PeerUser> {
 			final String username = CurrentUser.getInstance().getUsername();
 			Log.v(this.getClass().getSimpleName(),
 					"Sending current user information to " + this.getUsername() + " / " + this.getId() + ": " + username);
-			connection.send(
+			connection.send(new UserInformation(CurrentUser.getInstance()), null, errorCallback);
-					new UserInformation(CurrentUser.getInstance()),
-					null,
-					errorCallback);
 		} else {
 			Log.e(this.getClass().getSimpleName(), "Could not send new username: connection is not initialized");
 		}
 	}
 
-	private void sendUsernameTaken(TcpConnection thisConnection) {
+	protected void sendUsernameTaken() {
-		Log.v(this.getClass().getSimpleName(), "Received username request using current username");
+		if (connection != null) {
-		thisConnection.send(new UsernameTakenException("Username taken", getId()), this::disconnect, null);
+			Log.v(this.getClass().getSimpleName(), "Received username request using current username");
-	}
+			UsernameTakenException exception = new UsernameTakenException("Username taken",
-
+					CurrentUser.getInstance().getId(), getId());
-	public void init(TcpConnection connection, String id, String username, ErrorCallback errorCallback) {
+			connection.send(exception, connection::disconnect, null);
-		this.connection = connection;
+		} else {
-		this.setId(id);
+			Log.e(this.getClass().getSimpleName(), "Could not send UsernameTaken: connection is not initialized");
-		setUsername(username);
-		setState(UserState.CONNECTED);
-		subscribeToMessages((e) -> {
-			disconnect();
-			errorCallback.onError(e);
-		});
-	}
-
-	/**
-	 * Subscribe to this user messages.
-	 * If receiving new user info, update this user.
-	 * If receiving text message, store it in the history.
-	 *
-	 * @param errorCallback Callback on error
-	 */
-	private void subscribeToMessages(ErrorCallback errorCallback) {
-		connection.receive(
-				msg -> {
-					Log.v(this.getClass().getSimpleName(), "Received message from " + getId());
-					if (msg instanceof UserInformation) {
-						assert ((UserInformation) msg).id.equals(getId());
-						final String receivedUsername = ((UserInformation) msg).getUsername();
-						Log.v(this.getClass().getSimpleName(), "Message username: " + receivedUsername);
-						if (CurrentUser.getInstance().getUsername().equals(receivedUsername)) {
-							sendUsernameTaken(connection);
-						} else {
-							setUsername(receivedUsername);
-						}
-					} else if (msg instanceof Message) {
-						assert !((Message) msg).getRecipient().id.equals(getId());
-
-						Log.v(this.getClass().getSimpleName(), "Message text: " + ((Message) msg).getText());
-						if (msg instanceof FileMessage) {
-							((FileMessage) msg).storeFile();
-						}
-						history.addMessage((Message) msg, errorCallback);
-					} else if (msg instanceof UsernameTakenException) {
-						disconnect();
-						errorCallback.onError(new Exception("Received username already taken message"));
-					}
-				},
-				e -> {
-					if (e instanceof EOFException) {
-						disconnect();
-					} else {
-						Log.e(this.getClass().getSimpleName(), "Error receiving message from " + getId(), e);
-						errorCallback.onError(e);
-					}
-				});
-	}
-
-	/**
-	 * Close the connection and set state to disconnected
-	 */
-	public void disconnect() {
-		Log.v(this.getClass().getSimpleName(), "Disconnecting from user: " + getId());
-		closeConnection();
-		setState(UserState.DISCONNECTED);
-	}
-
-	@Override
-	protected void setUsername(String newUsername) {
-		super.setUsername(newUsername);
-		final DatabaseController db = new DatabaseController();
-		db.updateUsername(new UserInformation(this),
-				null,
-				e -> Log.e(getClass().getSimpleName(), "Unable to update the username", e));
-	}
-
-	/**
-	 * Close the connection to this user
-	 */
-	private void closeConnection() {
-		if (connection != null && connection.isOpen()) {
-			connection.close();
-			connection = null;
 		}
 	}
 
+	protected void addMessageToHistory(Message message, @Nullable ErrorCallback errorCallback) {
+		history.addMessage(message, errorCallback);
+	}
+
+
+	protected void onMessageReceived(Object msg, ErrorCallback errorCallback) throws IOException {
+		Log.v(this.getClass().getSimpleName(), "Received message from " + getId());
+		if (msg instanceof UserInformation) {
+			assert ((UserInformation) msg).id.equals(getId());
+			final String receivedUsername = ((UserInformation) msg).getUsername();
+			Log.v(this.getClass().getSimpleName(), "Message username: " + receivedUsername);
+			if (CurrentUser.getInstance().getUsername().equals(receivedUsername)) {
+				sendUsernameTaken();
+			} else {
+				setUsername(receivedUsername);
+			}
+		} else if (msg instanceof Message) {
+			assert !((Message) msg).getRecipient().id.equals(getId());
+
+			Log.v(this.getClass().getSimpleName(), "Message text: " + ((Message) msg).getText());
+			if (msg instanceof FileMessage) {
+				((FileMessage) msg).storeFile();
+			}
+			history.addMessage((Message) msg, errorCallback);
+		} else if (msg instanceof UsernameTakenException) {
+			disconnect();
+			errorCallback.onError(new Exception("Received username already taken message"));
+		}
+	}
+
+	public void disconnect() {
+		if (connection != null) {
+			Log.v(this.getClass().getSimpleName(), "Disconnecting from user: " + getId());
+			connection.disconnect();
+			connection = null;
+		}
+		setState(UserState.DISCONNECTED);
+	}
 
 	/**
 	 * Gets the value of history
@@ -203,6 +180,16 @@ public class PeerUser extends User implements Comparable<PeerUser> {
 		this.state = state;
 	}
 
+	@Override
+	protected void setUsername(String newUsername) {
+		super.setUsername(newUsername);
+		final DatabaseController db = new DatabaseController();
+		db.updateUsername(new UserInformation(this),
+				null,
+				e -> Log.e(getClass().getSimpleName(), "Unable to update the username", e));
+	}
+
+
 	/**
 	 * Check if this user is active.
 	 *

client/src/main/java/fr/insa/clavardator/client/users/ProxyPeerConnection.java

@@ -0,0 +1,43 @@
+package fr.insa.clavardator.client.users;
+
+import fr.insa.clavardator.client.server.Proxy;
+import fr.insa.clavardator.lib.network.TcpConnection;
+import fr.insa.clavardator.lib.util.ErrorCallback;
+import fr.insa.clavardator.lib.util.Log;
+import fr.insa.clavardator.lib.util.SimpleCallback;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.EOFException;
+import java.io.Serializable;
+
+public class ProxyPeerConnection extends PeerConnection {
+	private final Proxy proxy;
+
+	public ProxyPeerConnection(Proxy proxy, PeerUser user) {
+		super(user);
+		this.proxy = proxy;
+	}
+
+	@Override
+	protected void send(Serializable message, SimpleCallback callback, @Nullable ErrorCallback errorCallback) {
+		proxy.send(message, callback, errorCallback);
+	}
+
+
+	@Override
+	protected void receive(TcpConnection.MessageReceivedCallback callback, ErrorCallback errorCallback) {
+		proxy.receive(user.getId(), callback,
+				e -> {
+					disconnect();
+					if (!(e instanceof EOFException)) {
+						Log.e(this.getClass().getSimpleName(), "Error receiving message from " + user.getId(), e);
+						errorCallback.onError(e);
+					}
+				});
+	}
+
+	@Override
+	public void disconnect() {
+		proxy.disconnectUser(user.getId());
+	}
+}

client/src/main/java/fr/insa/clavardator/client/users/UserList.java

@@ -3,7 +3,7 @@ package fr.insa.clavardator.client.users;
 import fr.insa.clavardator.client.db.DatabaseController;
 import fr.insa.clavardator.client.network.NetDiscoverer;
 import fr.insa.clavardator.client.network.PeerHandshake;
-import fr.insa.clavardator.lib.network.TcpConnection;
+import fr.insa.clavardator.client.server.Proxy;
 import fr.insa.clavardator.lib.network.TcpListener;
 import fr.insa.clavardator.lib.users.User;
 import fr.insa.clavardator.lib.users.UserInformation;
@@ -47,7 +47,7 @@ public class UserList {
 		}, errorCallback);
 	}
 
-	public void onReceivePresenceNotification(ArrayList<UserInformation> newPresenceUsers, TcpConnection proxyConnection) {
+	public void onReceivePresenceNotification(ArrayList<UserInformation> newPresenceUsers, Proxy proxy) {
 		newPresenceUsers.forEach((userInfo -> {
 			final PeerUser savedUser = userHashmap.get(userInfo.id);
 			if (savedUser != null) {
@@ -55,12 +55,12 @@ public class UserList {
 					Log.v(getClass().getSimpleName(), "Received user from presence server already known and connected");
 				} else {
 					Log.v(getClass().getSimpleName(), "Received user from presence server already known but not connected, connecting...");
-					savedUser.init(proxyConnection, userInfo.id, userInfo.getUsername(), null);
+					savedUser.init(proxy, userInfo.id, userInfo.getUsername(), null);
 				}
 			} else {
 				Log.v(getClass().getSimpleName(), "Received new user from presence server");
 				final PeerUser user = new PeerUser();
-				user.init(proxyConnection, userInfo.id, userInfo.getUsername(), null);
+				user.init(proxy, userInfo.id, userInfo.getUsername(), null);
 				userHashmap.put(user.getId(), user);
 				Platform.runLater(() -> userObservableList.add(user));
 			}

lib/src/main/java/fr/insa/clavardator/lib/errors/UsernameTakenException.java

@@ -1,12 +1,27 @@
 package fr.insa.clavardator.lib.errors;
 
+import fr.insa.clavardator.lib.message.RecipientInfo;
+import fr.insa.clavardator.lib.message.SenderInfo;
+
 import java.io.Serializable;
 
-public class UsernameTakenException extends Exception implements Serializable {
+public class UsernameTakenException extends Exception implements Serializable, RecipientInfo, SenderInfo {
 	public final String recipient;
+	public final String sender;
 
-	public UsernameTakenException(String message, String recipient) {
+	public UsernameTakenException(String message, String sender, String recipient) {
 		super(message);
+		this.sender = sender;
 		this.recipient = recipient;
 	}
+
+	@Override
+	public String getRecipientId() {
+		return recipient;
+	}
+
+	@Override
+	public String getSenderId() {
+		return sender;
+	}
 }

lib/src/main/java/fr/insa/clavardator/lib/message/FileMessage.java

@@ -86,8 +86,9 @@ public class FileMessage extends Message {
 
 		// write to the file
 		if (rawFile == null) {
-			FileInputStream stream = new FileInputStream(fileName);
+			FileInputStream istream = new FileInputStream(fileName);
-			rawFile = stream.readAllBytes();
+			rawFile = istream.readAllBytes();
+			istream.close();
 		}
 
 		FileOutputStream ostream = new FileOutputStream(file);

lib/src/main/java/fr/insa/clavardator/lib/message/Message.java

@@ -6,7 +6,7 @@ import fr.insa.clavardator.lib.users.UserInformation;
 import java.io.Serializable;
 import java.util.Date;
 
-public class Message implements Serializable {
+public class Message implements Serializable, SenderInfo, RecipientInfo {
 	private final String text;
 	private final Date date;
 	private final UserInformation sender;
@@ -59,4 +59,14 @@ public class Message implements Serializable {
 				", recipient=" + recipient +
 				'}';
 	}
+
+	@Override
+	public String getSenderId() {
+		return sender.id;
+	}
+
+	@Override
+	public String getRecipientId() {
+		return recipient.id;
+	}
 }

lib/src/main/java/fr/insa/clavardator/lib/message/RecipientInfo.java

@@ -0,0 +1,5 @@
+package fr.insa.clavardator.lib.message;
+
+public interface RecipientInfo {
+	String getRecipientId();
+}

lib/src/main/java/fr/insa/clavardator/lib/message/SenderInfo.java

@@ -0,0 +1,5 @@
+package fr.insa.clavardator.lib.message;
+
+public interface SenderInfo {
+	String getSenderId();
+}

lib/src/main/java/fr/insa/clavardator/lib/network/TcpConnection.java

@@ -1,6 +1,7 @@
 package fr.insa.clavardator.lib.network;
 
 import fr.insa.clavardator.lib.util.ErrorCallback;
+import fr.insa.clavardator.lib.util.SimpleCallback;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -19,6 +20,7 @@ public class TcpConnection {
 	private ObjectInputStream inputStream;
 	private boolean shouldStop = false;
 	private final int port;
+	private final Object outputStreamGuard = new Object();
 
 	/**
 	 * Creates a new connection, and connects to the peer
@@ -61,7 +63,7 @@ public class TcpConnection {
 	 * @param callback      The function to call on success
 	 * @param errorCallback The function to call on error
 	 */
-	public void send(Serializable message, @Nullable MessageSentCallback callback, @Nullable ErrorCallback errorCallback) {
+	public void send(Serializable message, @Nullable SimpleCallback callback, @Nullable ErrorCallback errorCallback) {
 		Sender sender = new Sender(message, callback, errorCallback);
 		sender.start();
 	}
@@ -93,8 +95,10 @@ public class TcpConnection {
 	 */
 	public void close() {
 		shouldStop = true;
-		if (socket != null) {
+		if (outputStream != null) {
 			try {
+				outputStream.close();
+				inputStream.close();
 				socket.close();
 			} catch (IOException ignored) {
 			}
@@ -103,7 +107,8 @@ public class TcpConnection {
 
 	/**
 	 * Checks if the current connection is open
-	 * @return	True if the socket is still open
+	 *
+	 * @return True if the socket is still open
 	 */
 	public boolean isOpen() {
 		return socket != null && socket.isConnected() && !socket.isClosed();
@@ -138,31 +143,33 @@ public class TcpConnection {
 
 	private class Sender extends Thread {
 		private final Serializable message;
-		private final MessageSentCallback callback;
+		private final SimpleCallback callback;
 		private final ErrorCallback errorCallback;
 
 		/**
 		 * Constructs a thread that sends a message using the socket of the outer class
 		 *
-		 * @param message      The message to send
+		 * @param message       The message to send
 		 * @param callback      The function to call on success
 		 * @param errorCallback The function to call on error
 		 */
-		public Sender(Serializable message, @Nullable MessageSentCallback callback, @Nullable ErrorCallback errorCallback) {
+		public Sender(Serializable message, @Nullable SimpleCallback callback, @Nullable ErrorCallback errorCallback) {
 			this.message = message;
 			this.callback = callback;
 			this.errorCallback = errorCallback;
 		}
 
 		@Override
-		synchronized public void run() {
+		public void run() {
 			try {
-				if (outputStream == null) {
+				synchronized (outputStreamGuard) {
-					outputStream = new ObjectOutputStream(socket.getOutputStream());
+					if (outputStream == null) {
+						outputStream = new ObjectOutputStream(socket.getOutputStream());
+					}
+					outputStream.writeObject(message);
 				}
-				outputStream.writeObject(message);
 				if (callback != null)
-					callback.onMessageSent();
+					callback.call();
 			} catch (IOException e) {
 				if (errorCallback != null && !shouldStop)
 					errorCallback.onError(e);
@@ -211,9 +218,4 @@ public class TcpConnection {
 	public interface MessageReceivedCallback {
 		void onMessageReceived(Object msg) throws IOException;
 	}
-
-	public interface MessageSentCallback {
-		void onMessageSent();
-	}
-
 }

lib/src/main/java/fr/insa/clavardator/lib/network/TcpListener.java

@@ -49,7 +49,7 @@ public class TcpListener {
 		private final NewConnectionCallback callback;
 		private final ErrorCallback errorCallback;
 		private ServerSocket server;
-		private int port;
+		private final int port;
 
 		public Acceptor(int port, NewConnectionCallback callback, ErrorCallback errorCallback) {
 			this.port = port;
@@ -69,11 +69,11 @@ public class TcpListener {
 				if (!shouldStop)
 					errorCallback.onError(e);
 			}
-
 		}
 
 		public void stopAccepting() {
 			shouldStop = true;
+//			TODO: call interrupt() with ChannelServerSocket instead of closing the socket?
 			try {
 				server.close();
 			} catch (IOException ignored) {

lib/src/main/java/fr/insa/clavardator/lib/users/UserInformation.java

@@ -1,11 +1,13 @@
 package fr.insa.clavardator.lib.users;
 
+import fr.insa.clavardator.lib.message.SenderInfo;
+
 import java.io.Serializable;
 
 /**
  * Class used to serialize useful user information
  */
-public class UserInformation implements Serializable {
+public class UserInformation implements Serializable, SenderInfo {
 	public final String id;
 	private final String username;
 	private final UserState state;
@@ -46,4 +48,9 @@ public class UserInformation implements Serializable {
 	public String toString() {
 		return "UserInfo " + id + '(' + username + ')';
 	}
+
+	@Override
+	public String getSenderId() {
+		return id;
+	}
 }

server/src/main/java/fr/insa/clavardator/server/Proxy.java

@@ -1,7 +1,6 @@
 package fr.insa.clavardator.server;
 
-import fr.insa.clavardator.lib.errors.UsernameTakenException;
+import fr.insa.clavardator.lib.message.RecipientInfo;
-import fr.insa.clavardator.lib.message.Message;
 import fr.insa.clavardator.lib.network.TcpConnection;
 import fr.insa.clavardator.lib.network.TcpListener;
 import fr.insa.clavardator.lib.users.UserInformation;
@@ -24,17 +23,9 @@ public class Proxy {
 					Log.v(getClass().getSimpleName(), "Accepting a new user");
 					TcpConnection connection = new TcpConnection(clientSocket);
 					connection.receive(msg -> {
-
+						if (msg instanceof UserInformation) {
-						if (msg instanceof Message) {
+							// Send UserInformation to all other connected users
-							Log.v(getClass().getSimpleName(), "Transmitting message: " + msg);
+							Log.v(getClass().getSimpleName(), "Received UserInformation: " + msg);
-							transmitMessage((Serializable) msg, ((Message) msg).getRecipient().id);
-
-						} else if (msg instanceof UsernameTakenException) {
-							UsernameTakenException unameTaken = ((UsernameTakenException) msg);
-							transmitMessage(unameTaken, unameTaken.recipient);
-
-						} else if (msg instanceof UserInformation) {
-							Log.v(getClass().getSimpleName(), "Registering new user: " + msg);
 							users.put(((UserInformation) msg).id, connection);
 							for (String userId : users.keySet()) {
 								UserInformation userInfo = ((UserInformation) msg);
@@ -42,20 +33,25 @@ public class Proxy {
 									transmitMessage((Serializable) msg, userId);
 								}
 							}
+
+						} else if (msg instanceof RecipientInfo) {
+							// Send other messages only to the recipient
+							transmitMessage((Serializable) msg, ((RecipientInfo) msg).getRecipientId());
+						} else {
+							Log.e(getClass().getSimpleName(), "Unexpected message received: " + msg.toString());
 						}
 
 					}, e -> {
-						if (e instanceof EOFException) {
+						if (!(e instanceof EOFException)) {
-							for (Map.Entry<String, TcpConnection> user : users.entrySet()) {
-								if (user.getValue().equals(connection)) {
-									Log.v(getClass().getSimpleName(), "Disconnecting user " + user.getKey());
-									users.remove(user.getKey());
-									break;
-								}
-							}
-						} else {
 							Log.e(getClass().getSimpleName(), "Error while receiving message to transmit", e);
 						}
+						for (Map.Entry<String, TcpConnection> user : users.entrySet()) {
+							if (user.getValue().equals(connection)) {
+								Log.v(getClass().getSimpleName(), "Disconnecting user " + user.getKey());
+								users.remove(user.getKey());
+								break;
+							}
+						}
 					});
 				},
 				e -> Log.e(getClass().getSimpleName(), "Error while accepting a user", e));
@@ -67,6 +63,7 @@ public class Proxy {
 		if (user == null) {
 			Log.e(getClass().getSimpleName(), "Cannot find the recipient in the connected users");
 		} else {
+			Log.v(getClass().getSimpleName(), "Transmitting message: " + msg);
 			user.send(msg, null, e -> Log.e(getClass().getSimpleName(), "Error while sending message", e));
 		}
 	}