Added improved logging capabilities

src/main/java/envoy/client/data/Cache.java

@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.LinkedList;
 import java.util.Queue;
 import java.util.function.Consumer;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import envoy.util.EnvoyLog;
@@ -25,7 +26,7 @@ public class Cache<T> implements Consumer<T>, Serializable {
 	private transient Consumer<T>	processor;
 
 	private static final Logger	logger				= EnvoyLog.getLogger(Cache.class);
-	private static final long	serialVersionUID = 0L;
+	private static final long	serialVersionUID	= 0L;
 
 	/**
 	 * Adds an element to the cache.
@@ -35,7 +36,7 @@ public class Cache<T> implements Consumer<T>, Serializable {
 	 */
 	@Override
 	public void accept(T element) {
-		logger.fine(String.format("Adding element %s to cache", element));
+		logger.log(Level.FINE, String.format("Adding element %s to cache", element));
 		elements.offer(element);
 	}
 

src/main/java/envoy/client/net/Client.java

@@ -7,6 +7,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import envoy.client.data.Cache;
@@ -56,25 +57,29 @@ public class Client implements Closeable {
 	 * will block for up to 5 seconds. If the handshake does exceed this time limit,
 	 * an exception is thrown.
 	 *
-	 * @param credentials          the login credentials of the user
+	 * @param credentials                           the login credentials of the
-	 * @param receivedMessageCache a message cache containing all unread messages
+	 *                                              user
-	 *                             from the server that can be relayed after
+	 * @param receivedMessageCache                  a message cache containing all
-	 *                             initialization
+	 *                                              unread messages from the server
-	 * @param receivedMessageStatusChangeEventCache an event cache containing all received messageStatusChangeEvents from the server that can be relayed after initialization
+	 *                                              that can be relayed after
+	 *                                              initialization
+	 * @param receivedMessageStatusChangeEventCache an event cache containing all
+	 *                                              received
+	 *                                              messageStatusChangeEvents from
+	 *                                              the server that can be relayed
+	 *                                              after initialization
 	 * @throws TimeoutException     if the server could not be reached
-	 * @throws IOException          if the login credentials could not be
+	 * @throws IOException          if the login credentials could not be written
-	 *                              written
 	 * @throws InterruptedException if the current thread is interrupted while
 	 *                              waiting for the handshake response
 	 */
 	public void performHandshake(LoginCredentials credentials, Cache<Message> receivedMessageCache,
-			Cache<MessageStatusChangeEvent> receivedMessageStatusChangeEventCache)
+			Cache<MessageStatusChangeEvent> receivedMessageStatusChangeEventCache) throws TimeoutException, IOException, InterruptedException {
-			throws TimeoutException, IOException, InterruptedException {
 		if (online) throw new IllegalStateException("Handshake has already been performed successfully");
 		// Establish TCP connection
-		logger.finer(String.format("Attempting connection to server %s:%d...", config.getServer(), config.getPort()));
+		logger.log(Level.FINER, String.format("Attempting connection to server %s:%d...", config.getServer(), config.getPort()));
 		socket = new Socket(config.getServer(), config.getPort());
-		logger.fine("Successfully established TCP connection to server");
+		logger.log(Level.FINE, "Successfully established TCP connection to server");
 
 		// Create object receiver
 		receiver = new Receiver(socket.getInputStream());
@@ -114,19 +119,25 @@ public class Client implements Closeable {
 		// Remove all processors as they are only used during the handshake
 		receiver.removeAllProcessors();
 
-		logger.info("Handshake completed.");
+		logger.log(Level.INFO, "Handshake completed.");
 	}
 
 	/**
 	 * Initializes the {@link Receiver} used to process data sent from the server to
 	 * this client.
 	 *
-	 * @param localDB              the local database used to persist the current
+	 * @param localDB                               the local database used to
-	 *                             {@link IDGenerator}
+	 *                                              persist the current
-	 * @param receivedMessageCache a message cache containing all unread messages
+	 *                                              {@link IDGenerator}
-	 *                             from the server that can be relayed after
+	 * @param receivedMessageCache                  a message cache containing all
-	 *                             initialization
+	 *                                              unread messages from the server
-	 * @param receivedMessageStatusChangeEventCache an event cache containing all received messageStatusChangeEvents from the server that can be relayed after initialization
+	 *                                              that can be relayed after
+	 *                                              initialization
+	 * @param receivedMessageStatusChangeEventCache an event cache containing all
+	 *                                              received
+	 *                                              messageStatusChangeEvents from
+	 *                                              the server that can be relayed
+	 *                                              after initialization
 	 * @throws IOException if no {@link IDGenerator} is present and none could be
 	 *                     requested from the server
 	 * @since Envoy Client v0.2-alpha
@@ -136,7 +147,7 @@ public class Client implements Closeable {
 		checkOnline();
 
 		// Process incoming messages
-		final ReceivedMessageProcessor receivedMessageProcessor = new ReceivedMessageProcessor();
+		final ReceivedMessageProcessor			receivedMessageProcessor			= new ReceivedMessageProcessor();
 		final MessageStatusChangeEventProcessor	messageStatusChangeEventProcessor	= new MessageStatusChangeEventProcessor();
 
 		receiver.registerProcessor(Message.class, receivedMessageProcessor);
@@ -172,6 +183,7 @@ public class Client implements Closeable {
 				sendEvent(evt.get());
 			} catch (final IOException e) {
 				e.printStackTrace();
+				logger.log(Level.WARNING, "An error occurred when trying to send Event " + evt, e);
 			}
 		});
 
@@ -218,7 +230,7 @@ public class Client implements Closeable {
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public void requestIdGenerator() throws IOException {
-		logger.info("Requesting new id generator...");
+		logger.log(Level.INFO, "Requesting new id generator...");
 		writeObject(new IDGeneratorRequest());
 	}
 
@@ -240,7 +252,7 @@ public class Client implements Closeable {
 
 	private void writeObject(Object obj) throws IOException {
 		checkOnline();
-		logger.fine("Sending " + obj);
+		logger.log(Level.FINE, "Sending " + obj);
 		SerializationUtils.writeBytesWithLength(obj, socket.getOutputStream());
 	}
 
@@ -258,7 +270,7 @@ public class Client implements Closeable {
 	 * @param clientUser the client user to set
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public void setSender(User clientUser) { this.sender = clientUser; }
+	public void setSender(User clientUser) { sender = clientUser; }
 
 	/**
 	 * @return the {@link Receiver} used by this {@link Client}

src/main/java/envoy/client/net/MessageStatusChangeEventProcessor.java

@@ -1,6 +1,7 @@
 package envoy.client.net;
 
 import java.util.function.Consumer;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import envoy.data.Message.MessageStatus;
@@ -29,7 +30,7 @@ public class MessageStatusChangeEventProcessor implements Consumer<MessageStatus
 	 */
 	@Override
 	public void accept(MessageStatusChangeEvent evt) {
-		if (evt.get().ordinal() < MessageStatus.RECEIVED.ordinal()) logger.warning("Received invalid message status change " + evt);
+		if (evt.get().ordinal() < MessageStatus.RECEIVED.ordinal()) logger.log(Level.WARNING, "Received invalid message status change " + evt);
 		else EventBus.getInstance().dispatch(evt);
 	}
 }

src/main/java/envoy/client/net/ReceivedMessageProcessor.java

@@ -1,6 +1,7 @@
 package envoy.client.net;
 
 import java.util.function.Consumer;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import envoy.client.event.MessageCreationEvent;
@@ -23,7 +24,7 @@ public class ReceivedMessageProcessor implements Consumer<Message> {
 
 	@Override
 	public void accept(Message message) {
-		if (message.getStatus() != MessageStatus.SENT) logger.warning("The message has the unexpected status " + message.getStatus());
+		if (message.getStatus() != MessageStatus.SENT) logger.log(Level.WARNING, "The message has the unexpected status " + message.getStatus());
 		else {
 			// Update status to RECEIVED
 			message.nextStatus();

src/main/java/envoy/client/net/Receiver.java

@@ -45,7 +45,7 @@ public class Receiver extends Thread {
 	/**
 	 * Starts the receiver loop. When an object is read, it is passed to the
 	 * appropriate processor.
-	 * 
+	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
 	@Override
@@ -54,29 +54,29 @@ public class Receiver extends Thread {
 		try {
 			while (true) {
 				// Read object length
-				byte[] lenBytes = new byte[4];
+				final byte[] lenBytes = new byte[4];
 				in.read(lenBytes);
-				int len = SerializationUtils.bytesToInt(lenBytes, 0);
+				final int len = SerializationUtils.bytesToInt(lenBytes, 0);
 
 				// Read object into byte array
-				byte[] objBytes = new byte[len];
+				final byte[] objBytes = new byte[len];
 				in.read(objBytes);
 
 				try (ObjectInputStream oin = new ObjectInputStream(new ByteArrayInputStream(objBytes))) {
-					Object obj = oin.readObject();
+					final Object obj = oin.readObject();
-					logger.fine("Received " + obj);
+					logger.log(Level.FINE, "Received " + obj);
 
 					// Get appropriate processor
 					@SuppressWarnings("rawtypes")
-					Consumer processor = processors.get(obj.getClass());
+					final Consumer processor = processors.get(obj.getClass());
-					if (processor == null)
+					if (processor == null) logger.log(Level.WARNING,
-						logger.warning(String.format("The received object has the class %s for which no processor is defined.", obj.getClass()));
+							String.format("The received object has the class %s for which no processor is defined.", obj.getClass()));
 					else processor.accept(obj);
 				}
 			}
-		} catch (SocketException e) {
+		} catch (final SocketException e) {
 			// Connection probably closed by client.
-		} catch (Exception e) {
+		} catch (final Exception e) {
 			logger.log(Level.SEVERE, "Error on receiver thread", e);
 			e.printStackTrace();
 		}
@@ -94,7 +94,7 @@ public class Receiver extends Thread {
 
 	/**
 	 * Removes all object processors registered at this {@link Receiver}.
-	 * 
+	 *
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public void removeAllProcessors() { processors.clear(); }

src/main/java/envoy/client/net/WriteProxy.java

@@ -45,21 +45,21 @@ public class WriteProxy {
 		// Initialize cache processors for messages and message status change events
 		localDB.getMessageCache().setProcessor(msg -> {
 			try {
-				logger.finer("Sending cached " + msg);
+				logger.log(Level.FINER, "Sending cached " + msg);
 				client.sendMessage(msg);
 
 				// Update message state to SENT in localDB
 				localDB.getMessage(msg.getID()).ifPresent(Message::nextStatus);
-			} catch (IOException e) {
+			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message", e);
+				logger.log(Level.SEVERE, "Could not send cached message: ", e);
 			}
 		});
 		localDB.getStatusCache().setProcessor(evt -> {
-			logger.finer("Sending cached " + evt);
+			logger.log(Level.FINER, "Sending cached " + evt);
 			try {
 				client.sendEvent(evt);
-			} catch (IOException e) {
+			} catch (final IOException e) {
-				logger.log(Level.SEVERE, "Could not send cached message status change event", e);
+				logger.log(Level.SEVERE, "Could not send cached message status change event: ", e);
 			}
 		});
 	}

src/main/java/envoy/client/ui/MessageListCell.java

@@ -3,6 +3,7 @@ package envoy.client.ui;
 import java.io.IOException;
 import java.text.SimpleDateFormat;
 import java.util.Map;
+import java.util.logging.Level;
 
 import javafx.scene.control.Label;
 import javafx.scene.control.ListCell;
@@ -13,6 +14,7 @@ import javafx.scene.layout.VBox;
 
 import envoy.data.Message;
 import envoy.data.Message.MessageStatus;
+import envoy.util.EnvoyLog;
 
 /**
  * Displays a single message inside the message list.
@@ -20,7 +22,7 @@ import envoy.data.Message.MessageStatus;
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>MessageListCell.java</strong><br>
  * Created: <strong>28.03.2020</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
@@ -32,20 +34,21 @@ public class MessageListCell extends ListCell<Message> {
 	static {
 		try {
 			statusImages = IconUtil.loadByEnum(MessageStatus.class, 32);
-		} catch (IOException e) {
+		} catch (final IOException e) {
 			e.printStackTrace();
+			EnvoyLog.getLogger(MessageListCell.class).log(Level.WARNING, "could not load status icons: ", e);
 		}
 	}
 
 	/**
 	 * Displays the text, the data of creation and the status of a message.
-	 * 
+	 *
 	 * @since Envoy v0.1-beta
 	 */
 	@Override
 	protected void updateItem(Message message, boolean empty) {
 		super.updateItem(message, empty);
-		if(empty || message == null) {
+		if (empty || message == null) {
 			setText(null);
 			setGraphic(null);
 		} else {

src/main/java/envoy/client/ui/SceneContext.java

@@ -2,6 +2,7 @@ package envoy.client.ui;
 
 import java.io.IOException;
 import java.util.Stack;
+import java.util.logging.Level;
 
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
@@ -11,6 +12,7 @@ import javafx.stage.Stage;
 import envoy.client.data.Settings;
 import envoy.client.event.ThemeChangeEvent;
 import envoy.event.EventBus;
+import envoy.util.EnvoyLog;
 
 /**
  * Manages a stack of scenes. The most recently added scene is displayed inside
@@ -23,7 +25,7 @@ import envoy.event.EventBus;
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>SceneContext.java</strong><br>
  * Created: <strong>06.06.2020</strong><br>
- * 
+ *
  * @author Kai S. K. Engelbart
  * @since Envoy Client v0.1-beta
  */
@@ -31,43 +33,43 @@ public final class SceneContext {
 
 	/**
 	 * Contains information about different scenes and their FXML resource files.
-	 * 
+	 *
 	 * @author Kai S. K. Engelbart
 	 * @since Envoy Client v0.1-beta
 	 */
-	public static enum SceneInfo {
+	public enum SceneInfo {
 
 		/**
 		 * The main scene in which chats are displayed.
-		 * 
+		 *
 		 * @since Envoy Client v0.1-beta
 		 */
 		CHAT_SCENE("/fxml/ChatScene.fxml"),
 
 		/**
 		 * The scene in which settings are displayed.
-		 * 
+		 *
 		 * @since Envoy Client v0.1-beta
 		 */
 		SETTINGS_SCENE("/fxml/SettingsScene.fxml"),
 
 		/**
 		 * The scene in which the contact search is displayed.
-		 * 
+		 *
 		 * @since Envoy Client v0.1-beta
 		 */
 		CONTACT_SEARCH_SCENE("/fxml/ContactSearchScene.fxml"),
 
 		/**
 		 * The scene in which the group creation screen is displayed.
-		 * 
+		 *
 		 * @since Envoy Client v0.1-beta
 		 */
 		GROUP_CREATION_SCENE("/fxml/GroupCreationScene.fxml"),
 
 		/**
 		 * The scene in which the login screen is displayed.
-		 * 
+		 *
 		 * @since Envoy Client v0.1-beta
 		 */
 		LOGIN_SCENE("/fxml/LoginScene.fxml");
@@ -88,7 +90,7 @@ public final class SceneContext {
 
 	/**
 	 * Initializes the scene context.
-	 * 
+	 *
 	 * @param stage the stage in which scenes will be displayed
 	 * @since Envoy Client v0.1-beta
 	 */
@@ -99,7 +101,7 @@ public final class SceneContext {
 
 	/**
 	 * Loads a new scene specified by a scene info.
-	 * 
+	 *
 	 * @param sceneInfo specifies the scene to load
 	 * @throws RuntimeException if the loading process fails
 	 * @since Envoy Client v0.1-beta
@@ -117,14 +119,15 @@ public final class SceneContext {
 			applyCSS();
 			stage.sizeToScene();
 			stage.show();
-		} catch (IOException e) {
+		} catch (final IOException e) {
+			EnvoyLog.getLogger(SceneContext.class).log(Level.SEVERE, String.format("Could not load scene for %s: ", sceneInfo), e);
 			throw new RuntimeException(e);
 		}
 	}
 
 	/**
 	 * Removes the current scene and displays the previous one.
-	 * 
+	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void pop() {

src/main/java/envoy/client/ui/Startup.java

@@ -2,6 +2,7 @@ package envoy.client.ui;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Date;
 import java.util.Properties;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -33,9 +34,9 @@ import envoy.util.EnvoyLog;
  */
 public final class Startup extends Application {
 
-	private LocalDB			localDB;
+	private LocalDB							localDB;
-	private Client			client;
+	private Client							client;
-	private Cache<Message>	messageCache;
+	private Cache<Message>					messageCache;
 	private Cache<MessageStatusChangeEvent>	messageStatusCache;
 
 	private static final ClientConfig	config	= ClientConfig.getInstance();
@@ -44,13 +45,14 @@ public final class Startup extends Application {
 	/**
 	 * Loads the configuration, initializes the client and the local database and
 	 * delegates the rest of the startup process to {@link LoginScene}.
-	 * 
+	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@Override
 	public void start(Stage stage) throws Exception {
 		try {
 			// Load the configuration from client.properties first
+			logger.log(Level.INFO, "Envoy was started at " + new Date());
 			final Properties properties = new Properties();
 			properties.load(Startup.class.getClassLoader().getResourceAsStream("client.properties"));
 			config.load(properties);
@@ -63,6 +65,7 @@ public final class Startup extends Application {
 			if (!config.isInitialized()) throw new EnvoyException("Configuration is not fully initialized");
 		} catch (final Exception e) {
 			new Alert(AlertType.ERROR, "Error loading configuration values:\n" + e);
+			logger.log(Level.SEVERE, "Error loading configuration values", e);
 			e.printStackTrace();
 			System.exit(1);
 		}
@@ -77,20 +80,18 @@ public final class Startup extends Application {
 		if (config.isIgnoreLocalDB()) {
 			localDB = new TransientLocalDB();
 			new Alert(AlertType.WARNING, "Ignoring local database.\nMessages will not be saved!").showAndWait();
-		} else {
+		} else try {
-			try {
+			localDB = new PersistentLocalDB(new File(config.getHomeDirectory(), config.getLocalDB().getPath()));
-				localDB = new PersistentLocalDB(new File(config.getHomeDirectory(), config.getLocalDB().getPath()));
+		} catch (final IOException e3) {
-			} catch (final IOException e3) {
+			logger.log(Level.SEVERE, "Could not initialize local database: ", e3);
-				logger.log(Level.SEVERE, "Could not initialize local database", e3);
+			new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e3).showAndWait();
-				new Alert(AlertType.ERROR, "Could not initialize local database!\n" + e3).showAndWait();
+			System.exit(1);
-				System.exit(1);
+			return;
-				return;
-			}
 		}
 
 		// Initialize client and unread message cache
-		client	= new Client();
+		client				= new Client();
-		messageCache	= new Cache<>();
+		messageCache		= new Cache<>();
 		messageStatusCache	= new Cache<>();
 
 		stage.setTitle("Envoy");
@@ -103,20 +104,21 @@ public final class Startup extends Application {
 
 	/**
 	 * Closes the client connection and saves the local database and settings.
-	 * 
+	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@Override
 	public void stop() {
 		try {
-			logger.info("Closing connection...");
+			logger.log(Level.INFO, "Closing connection...");
 			client.close();
 
-			logger.info("Saving local database and settings...");
+			logger.log(Level.INFO, "Saving local database and settings...");
 			localDB.save();
 			Settings.getInstance().save();
+			logger.log(Level.INFO, "Envoy was stopped as expected at " + new Date());
 		} catch (final Exception e) {
-			logger.log(Level.SEVERE, "Unable to save local files", e);
+			logger.log(Level.SEVERE, "Unable to save local files: ", e);
 		}
 	}
 

src/main/java/envoy/client/ui/StatusTrayIcon.java

@@ -4,11 +4,13 @@ import java.awt.*;
 import java.awt.TrayIcon.MessageType;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
+import java.util.logging.Level;
 
 import envoy.client.event.MessageCreationEvent;
 import envoy.data.Message;
 import envoy.event.EventBus;
 import envoy.exception.EnvoyException;
+import envoy.util.EnvoyLog;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -25,7 +27,7 @@ public class StatusTrayIcon {
 	 * system tray. This includes displaying the icon, but also creating
 	 * notifications when new messages are received.
 	 */
-	private TrayIcon trayIcon;
+	private final TrayIcon trayIcon;
 
 	/**
 	 * A received {@link Message} is only displayed as a system tray notification if
@@ -46,16 +48,16 @@ public class StatusTrayIcon {
 	public StatusTrayIcon(Window focusTarget) throws EnvoyException {
 		if (!SystemTray.isSupported()) throw new EnvoyException("The Envoy tray icon is not supported.");
 
-		ClassLoader	loader	= Thread.currentThread().getContextClassLoader();
+		final ClassLoader	loader	= Thread.currentThread().getContextClassLoader();
-		Image		img		= Toolkit.getDefaultToolkit().createImage(loader.getResource("envoy_logo.png"));
+		final Image			img		= Toolkit.getDefaultToolkit().createImage(loader.getResource("envoy_logo.png"));
 		trayIcon = new TrayIcon(img, "Envoy Client");
 		trayIcon.setImageAutoSize(true);
 		trayIcon.setToolTip("You are notified if you have unread messages.");
 
-		PopupMenu popup = new PopupMenu();
+		final PopupMenu popup = new PopupMenu();
 
-		MenuItem exitMenuItem = new MenuItem("Exit");
+		final MenuItem exitMenuItem = new MenuItem("Exit");
-		exitMenuItem.addActionListener((evt) -> System.exit(0));
+		exitMenuItem.addActionListener(evt -> System.exit(0));
 		popup.add(exitMenuItem);
 
 		trayIcon.setPopupMenu(popup);
@@ -71,7 +73,7 @@ public class StatusTrayIcon {
 		});
 
 		// Show the window if the user clicks on the icon
-		trayIcon.addActionListener((evt) -> { focusTarget.setVisible(true); focusTarget.requestFocus(); });
+		trayIcon.addActionListener(evt -> { focusTarget.setVisible(true); focusTarget.requestFocus(); });
 
 		// Start processing message events
 		// TODO: Handle other message types
@@ -90,7 +92,8 @@ public class StatusTrayIcon {
 	public void show() throws EnvoyException {
 		try {
 			SystemTray.getSystemTray().add(trayIcon);
-		} catch (AWTException e) {
+		} catch (final AWTException e) {
+			EnvoyLog.getLogger(StatusTrayIcon.class).log(Level.INFO, "Could not display StatusTrayIcon: ", e);
 			throw new EnvoyException("Could not attach Envoy tray icon to system tray.", e);
 		}
 	}

src/main/java/envoy/client/ui/controller/ChatScene.java

@@ -92,14 +92,12 @@ public final class ChatScene {
 				chat.getMessages().add(message);
 
 				// Update UI if in current chat
-				if (chat == currentChat)
+				if (chat == currentChat) Platform.runLater(messageList::refresh);
-					Platform.runLater(messageList::refresh);
 			});
 		});
 
 		// Listen to message status changes
-		eventBus.register(MessageStatusChangeEvent.class, e ->
+		eventBus.register(MessageStatusChangeEvent.class, e -> localDB.getMessage(e.getID()).ifPresent(message -> {
-			localDB.getMessage(e.getID()).ifPresent(message -> {
 			message.setStatus(e.get());
 
 			// Update UI if in current chat
@@ -107,16 +105,12 @@ public final class ChatScene {
 		}));
 
 		// Listen to user status changes
-		eventBus.register(UserStatusChangeEvent.class, e ->
+		eventBus.register(UserStatusChangeEvent.class,
-			userList.getItems()
+				e -> userList.getItems()
-				.stream()
+					.stream()
-				.filter(c -> c.getID() == e.getID())
+					.filter(c -> c.getID() == e.getID())
-				.findAny()
+					.findAny()
-				.ifPresent(u -> {
+					.ifPresent(u -> { ((User) u).setStatus(e.get()); Platform.runLater(userList::refresh); }));
-					((User) u).setStatus(e.get());
-					Platform.runLater(userList::refresh);
-				})
-		);
 
 		// Listen to contacts changes
 		eventBus.register(ContactOperationEvent.class, e -> {
@@ -169,8 +163,7 @@ public final class ChatScene {
 			// LEON: JFC <===> JAVA FRIED CHICKEN <=/=> Java Foundation Classes
 
 			// Load the chat or create a new one and add it to the LocalDB
-			currentChat = localDB
+			currentChat = localDB.getChat(user.getID())
-				.getChat(user.getID())
 				.orElseGet(() -> { final var chat = new Chat(user); localDB.getChats().add(chat); return chat; });
 
 			messageList.setItems(FXCollections.observableList(currentChat.getMessages()));
@@ -264,7 +257,7 @@ public final class ChatScene {
 			if (!localDB.getIDGenerator().hasNext() && client.isOnline()) client.requestIdGenerator();
 
 		} catch (final IOException e) {
-			logger.log(Level.SEVERE, "Error sending message", e);
+			logger.log(Level.SEVERE, "Error sending message: ", e);
 			new Alert(AlertType.ERROR, "An error occured while sending the message!").showAndWait();
 		}
 

src/main/java/envoy/client/ui/controller/ContactSearchScene.java

@@ -57,6 +57,7 @@ public class ContactSearchScene {
 
 	/**
 	 * @param sceneContext enables the user to return to the chat scene
+	 * @param localDB      the {@link LocalDB} that is used to save contacts
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void initializeData(SceneContext sceneContext, LocalDB localDB) {
@@ -67,10 +68,8 @@ public class ContactSearchScene {
 	@FXML
 	private void initialize() {
 		contactList.setCellFactory(e -> new ContactListCell());
-		eventBus.register(ContactSearchResult.class, response -> Platform.runLater(() -> {
+		eventBus.register(ContactSearchResult.class,
-			contactList.getItems().clear();
+				response -> Platform.runLater(() -> { contactList.getItems().clear(); contactList.getItems().addAll(response.get()); }));
-			contactList.getItems().addAll(response.get());
-		}));
 	}
 
 	/**
@@ -115,7 +114,7 @@ public class ContactSearchScene {
 	 */
 	@FXML
 	private void contactListClicked() {
-		final var	contact	= contactList.getSelectionModel().getSelectedItem();
+		final var contact = contactList.getSelectionModel().getSelectedItem();
 		if (contact != null) {
 			final var alert = new Alert(AlertType.CONFIRMATION);
 			alert.setTitle("Add Contact to Contact List");

src/main/java/envoy/client/ui/controller/GroupCreationScene.java

@@ -39,7 +39,7 @@ public class GroupCreationScene {
 
 	private SceneContext sceneContext;
 
-	private static EventBus		eventBus	= EventBus.getInstance();
+	private static EventBus eventBus = EventBus.getInstance();
 
 	@FXML
 	private void initialize() {
@@ -49,10 +49,11 @@ public class GroupCreationScene {
 
 	/**
 	 * @param sceneContext enables the user to return to the chat scene
+	 * @param localDB      the {@link LocalDB} that is used to save contacts
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void initializeData(SceneContext sceneContext, LocalDB localDB) {
-		this.sceneContext	= sceneContext;
+		this.sceneContext = sceneContext;
 		Platform.runLater(() -> contactList.getItems()
 			.addAll(localDB.getUsers()
 				.values()

src/main/java/envoy/client/ui/controller/LoginScene.java

@@ -3,6 +3,7 @@ package envoy.client.ui.controller;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javafx.application.Platform;
@@ -54,11 +55,11 @@ public final class LoginScene {
 	@FXML
 	private Label connectionLabel;
 
-	private Client			client;
+	private Client							client;
-	private LocalDB			localDB;
+	private LocalDB							localDB;
-	private Cache<Message>	receivedMessageCache;
+	private Cache<Message>					receivedMessageCache;
 	private Cache<MessageStatusChangeEvent>	receivedMessageStatusChangeEventCache;
-	private SceneContext	sceneContext;
+	private SceneContext					sceneContext;
 
 	private static final Logger			logger		= EnvoyLog.getLogger(LoginScene.class);
 	private static final EventBus		eventBus	= EventBus.getInstance();
@@ -76,22 +77,28 @@ public final class LoginScene {
 	/**
 	 * Loads the login dialog using the FXML file {@code LoginDialog.fxml}.
 	 *
-	 * @param client               the client used to perform the handshake
+	 * @param client                                the client used to perform the
-	 * @param localDB              the local database used for offline login
+	 *                                              handshake
-	 * @param receivedMessageCache the cache storing messages received during
+	 * @param localDB                               the local database used for
-	 *                             the handshake
+	 *                                              offline login
-	 * @param receivedMessageStatusChangeEventCache the cache storing messageStatusChangeEvents received during handshake
+	 * @param receivedMessageCache                  the cache storing messages
-	 * @param sceneContext         the scene context used to initialize the chat
+	 *                                              received during
-	 *                             scene
+	 *                                              the handshake
+	 * @param receivedMessageStatusChangeEventCache the cache storing
+	 *                                              messageStatusChangeEvents
+	 *                                              received during handshake
+	 * @param sceneContext                          the scene context used to
+	 *                                              initialize the chat
+	 *                                              scene
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void initializeData(Client client, LocalDB localDB, Cache<Message> receivedMessageCache,
 			Cache<MessageStatusChangeEvent> receivedMessageStatusChangeEventCache, SceneContext sceneContext) {
-		this.client					= client;
+		this.client									= client;
-		this.localDB				= localDB;
+		this.localDB								= localDB;
-		this.receivedMessageCache	= receivedMessageCache;
+		this.receivedMessageCache					= receivedMessageCache;
 		this.receivedMessageStatusChangeEventCache	= receivedMessageStatusChangeEventCache;
-		this.sceneContext			= sceneContext;
+		this.sceneContext							= sceneContext;
 
 		// Prepare handshake
 		localDB.loadIDGenerator();
@@ -129,7 +136,7 @@ public final class LoginScene {
 
 	@FXML
 	private void abortLogin() {
-		logger.info("The login process has been cancelled. Exiting...");
+		logger.log(Level.INFO, "The login process has been cancelled. Exiting...");
 		System.exit(0);
 	}
 
@@ -141,8 +148,8 @@ public final class LoginScene {
 				loadChatScene();
 			}
 		} catch (IOException | InterruptedException | TimeoutException e) {
-			logger.warning("Could not connect to server: " + e);
+			logger.log(Level.WARNING, "Could not connect to server: ", e);
-			logger.finer("Attempting offline mode...");
+			logger.log(Level.FINER, "Attempting offline mode...");
 			attemptOfflineMode(credentials);
 		}
 	}
@@ -158,6 +165,7 @@ public final class LoginScene {
 			loadChatScene();
 		} catch (final Exception e) {
 			new Alert(AlertType.ERROR, "Client error: " + e).showAndWait();
+			logger.log(Level.SEVERE, "Offline mode could not be loaded: ", e);
 			System.exit(1);
 		}
 	}
@@ -176,6 +184,7 @@ public final class LoginScene {
 		} catch (final Exception e) {
 			e.printStackTrace();
 			new Alert(AlertType.ERROR, "Error while loading local database: " + e + "\nChats will not be stored locally.").showAndWait();
+			logger.log(Level.WARNING, "Could not load local database: ", e);
 		}
 
 		// Initialize write proxy