Merge branch 'develop' into f/system_commands

client/.project

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>envoy-client</name>
+	<name>client</name>
 	<comment></comment>
 	<projects>
 	</projects>

client/.settings/org.hibernate.eclipse.console.prefs

@@ -1,3 +0,0 @@
-default.configuration=
-eclipse.preferences.version=1
-hibernate3.enabled=false

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

@@ -5,10 +5,8 @@ import static java.util.function.Function.identity;
 import java.io.File;
 import java.util.logging.Level;
 
-import envoy.client.ui.Startup;
 import envoy.data.Config;
 import envoy.data.ConfigItem;
-import envoy.data.LoginCredentials;
 
 /**
  * Implements a configuration specific to the Envoy Client with default values
@@ -40,8 +38,8 @@ public class ClientConfig extends Config {
 		items.put("localDB", new ConfigItem<>("localDB", "db", File::new, new File("localDB"), true));
 		items.put("ignoreLocalDB", new ConfigItem<>("ignoreLocalDB", "nodb", Boolean::parseBoolean, false, false));
 		items.put("homeDirectory", new ConfigItem<>("homeDirectory", "h", File::new, new File(System.getProperty("user.home"), ".envoy"), true));
-		items.put("fileLevelBarrier", new ConfigItem<>("fileLevelBarrier", "fb", Level::parse, Level.CONFIG, true));
+		items.put("fileLevelBarrier", new ConfigItem<>("fileLevelBarrier", "fb", Level::parse, Level.OFF, true));
-		items.put("consoleLevelBarrier", new ConfigItem<>("consoleLevelBarrier", "cb", Level::parse, Level.FINEST, true));
+		items.put("consoleLevelBarrier", new ConfigItem<>("consoleLevelBarrier", "cb", Level::parse, Level.OFF, true));
 		items.put("user", new ConfigItem<>("user", "u", identity()));
 		items.put("password", new ConfigItem<>("password", "pw", identity()));
 	}
@@ -105,11 +103,4 @@ public class ClientConfig extends Config {
 	 * @since Envoy Client v0.3-alpha
 	 */
 	public boolean hasLoginCredentials() { return getUser() != null && getPassword() != null; }
-
-	/**
-	 * @return login credentials for the specified user name and password, without
-	 *         the registration option
-	 * @since Envoy Client v0.3-alpha
-	 */
-	public LoginCredentials getLoginCredentials() { return new LoginCredentials(getUser(), getPassword(), false, Startup.VERSION); }
 }

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

@@ -1,7 +1,7 @@
 package envoy.client.data;
 
 import java.io.IOException;
-import java.time.LocalDateTime;
+import java.time.Instant;
 
 import envoy.client.net.WriteProxy;
 import envoy.data.Contact;
@@ -46,7 +46,7 @@ public class GroupChat extends Chat {
 				else {
 					gmsg.getMemberStatuses().replace(sender.getID(), MessageStatus.READ);
 					writeProxy
-						.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(), MessageStatus.READ, LocalDateTime.now(), sender.getID()));
+						.writeMessageStatusChange(new GroupMessageStatusChange(gmsg.getID(), MessageStatus.READ, Instant.now(), sender.getID()));
 				}
 			}
 		}

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

@@ -1,5 +1,6 @@
 package envoy.client.data;
 
+import java.time.Instant;
 import java.util.*;
 
 import envoy.data.*;
@@ -20,11 +21,12 @@ import envoy.event.NameChange;
  */
 public abstract class LocalDB {
 
-	protected User					user;
+	protected User				user;
-	protected Map<String, Contact>	users		= new HashMap<>();
+	protected Map<String, User>	users		= new HashMap<>();
-	protected List<Chat>			chats		= new ArrayList<>();
+	protected List<Chat>		chats		= new ArrayList<>();
-	protected IDGenerator			idGenerator;
+	protected IDGenerator		idGenerator;
-	protected CacheMap				cacheMap	= new CacheMap();
+	protected CacheMap			cacheMap	= new CacheMap();
+	protected Instant			lastSync	= Instant.EPOCH;
 
 	{
 		cacheMap.put(Message.class, new Cache<>());
@@ -42,10 +44,11 @@ public abstract class LocalDB {
 	 * Stores all users. If the client user is specified, their chats will be stored
 	 * as well. The message id generator will also be saved if present.
 	 *
+	 * @param isOnline determines which {@code lastSync} time stamp is saved
 	 * @throws Exception if the saving process failed
 	 * @since Envoy Client v0.3-alpha
 	 */
-	public void save() throws Exception {}
+	public void save(boolean isOnline) throws Exception {}
 
 	/**
 	 * Loads all user data.
@@ -77,7 +80,7 @@ public abstract class LocalDB {
 	 * @since Envoy Client v0.1-beta
 	 */
 	public void synchronize() {
-		user.getContacts().stream().filter(u -> u instanceof User && !users.containsKey(u.getName())).forEach(u -> users.put(u.getName(), u));
+		user.getContacts().stream().filter(u -> u instanceof User && !users.containsKey(u.getName())).forEach(u -> users.put(u.getName(), (User) u));
 		users.put(user.getName(), user);
 
 		// Synchronize user status data
@@ -98,7 +101,7 @@ public abstract class LocalDB {
 	 *         user names as keys
 	 * @since Envoy Client v0.2-alpha
 	 */
-	public Map<String, Contact> getUsers() { return users; }
+	public Map<String, User> getUsers() { return users; }
 
 	/**
 	 * @return all saved {@link Chat} objects that list the client user as the
@@ -148,6 +151,12 @@ public abstract class LocalDB {
 	 */
 	public CacheMap getCacheMap() { return cacheMap; }
 
+	/**
+	 * @return the time stamp when the database was last saved
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Instant getLastSync() { return lastSync; }
+
 	/**
 	 * Searches for a message by ID.
 	 *

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

@@ -1,6 +1,7 @@
 package envoy.client.data;
 
 import java.io.*;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.HashMap;
 
@@ -26,7 +27,7 @@ public final class PersistentLocalDB extends LocalDB {
 	/**
 	 * Constructs an empty local database. To serialize any user-specific data to
 	 * the file system, call {@link PersistentLocalDB#initializeUserStorage()} first
-	 * and then {@link PersistentLocalDB#save()}.
+	 * and then {@link PersistentLocalDB#save(boolean)}.
 	 *
 	 * @param dbDir the directory in which to persist data
 	 * @throws IOException if {@code dbDir} is a file (and not a directory)
@@ -57,12 +58,12 @@ public final class PersistentLocalDB extends LocalDB {
 	}
 
 	@Override
-	public void save() throws IOException {
+	public void save(boolean isOnline) throws IOException {
 		// Save users
 		SerializationUtils.write(usersFile, users);
 
-		// Save user data
+		// Save user data and last sync time stamp
-		if (user != null) SerializationUtils.write(userFile, chats, cacheMap);
+		if (user != null) SerializationUtils.write(userFile, chats, cacheMap, isOnline ? Instant.now() : lastSync);
 
 		// Save id generator
 		if (hasIDGenerator()) SerializationUtils.write(idGeneratorFile, idGenerator);
@@ -76,6 +77,7 @@ public final class PersistentLocalDB extends LocalDB {
 		try (var in = new ObjectInputStream(new FileInputStream(userFile))) {
 			chats		= (ArrayList<Chat>) in.readObject();
 			cacheMap	= (CacheMap) in.readObject();
+			lastSync	= (Instant) in.readObject();
 		}
 	}
 

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

@@ -1,14 +1,11 @@
 package envoy.client.net;
 
 import java.util.function.Consumer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 import envoy.client.event.MessageCreationEvent;
 import envoy.data.Message;
 import envoy.data.Message.MessageStatus;
 import envoy.event.EventBus;
-import envoy.util.EnvoyLog;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -20,17 +17,12 @@ import envoy.util.EnvoyLog;
  */
 public class ReceivedMessageProcessor implements Consumer<Message> {
 
-	private static final Logger logger = EnvoyLog.getLogger(ReceivedMessageProcessor.class);
-
 	@Override
 	public void accept(Message message) {
-		if (message.getStatus() != MessageStatus.SENT) logger.log(Level.WARNING, "The message has the unexpected status " + message.getStatus());
+		// Update status to RECEIVED
-		else {
+		if (message.getStatus() == MessageStatus.SENT) message.nextStatus();
-			// Update status to RECEIVED
-			message.nextStatus();
 
-			// Dispatch event
+		// Dispatch event
-			EventBus.getInstance().dispatch(new MessageCreationEvent(message));
+		EventBus.getInstance().dispatch(new MessageCreationEvent(message));
-		}
 	}
 }

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

@@ -121,12 +121,13 @@ public final class Startup extends Application {
 	@Override
 	public void stop() {
 		try {
+			logger.log(Level.INFO, "Saving local database and settings...");
+			localDB.save(client.isOnline());
+			Settings.getInstance().save();
+
 			logger.log(Level.INFO, "Closing connection...");
 			client.close();
 
-			logger.log(Level.INFO, "Saving local database and settings...");
-			localDB.save();
-			Settings.getInstance().save();
 			logger.log(Level.INFO, "Envoy was terminated by its user");
 		} catch (final Exception e) {
 			logger.log(Level.SEVERE, "Unable to save local files: ", e);

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

@@ -1,5 +1,7 @@
 package envoy.client.ui.controller;
 
+import static envoy.data.Message.MessageStatus.RECEIVED;
+
 import java.awt.Toolkit;
 import java.awt.datatransfer.StringSelection;
 import java.io.ByteArrayInputStream;
@@ -134,7 +136,13 @@ public final class ChatScene implements Restorable {
 		// Listen to received messages
 		eventBus.register(MessageCreationEvent.class, e -> {
 			final var message = e.get();
-			localDB.getChat(message instanceof GroupMessage ? message.getRecipientID() : message.getSenderID()).ifPresent(chat -> {
+
+			// The sender of the message is the recipient of the chat
+			// Exceptions: this user is the sender (sync) or group message (group is
+			// recipient)
+			final long recipientID = message instanceof GroupMessage || message.getSenderID() == localDB.getUser().getID() ? message.getRecipientID()
+					: message.getSenderID();
+			localDB.getChat(recipientID).ifPresent(chat -> {
 				chat.insert(message);
 				if (chat.equals(currentChat)) {
 					try {
@@ -143,8 +151,10 @@ public final class ChatScene implements Restorable {
 						logger.log(Level.WARNING, "Could not read current chat: ", e1);
 					}
 					Platform.runLater(() -> { ListViewRefresh.deepRefresh(messageList); scrollToMessageListEnd(); });
-				} else chat.incrementUnreadAmount();
+					// TODO: Increment unread counter for group messages with status < RECEIVED
-				// Moving chat with most recent unreadMessages to the top
+				} else if (message.getSenderID() != localDB.getUser().getID() && message.getStatus() == RECEIVED) chat.incrementUnreadAmount();
+
+				// Move chat with most recent unread messages to the top
 				Platform.runLater(() -> {
 					chatList.getItems().remove(chat);
 					chatList.getItems().add(0, chat);
@@ -182,12 +192,11 @@ public final class ChatScene implements Restorable {
 			final var contact = e.get();
 			switch (e.getOperationType()) {
 				case ADD:
-					localDB.getUsers().put(contact.getName(), contact);
+					if (contact instanceof User) localDB.getUsers().put(contact.getName(), (User) contact);
-					final Chat chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
+					Chat chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
 					Platform.runLater(() -> chatList.getItems().add(chat));
 					break;
 				case REMOVE:
-					localDB.getUsers().remove(contact.getName());
 					Platform.runLater(() -> chatList.getItems().removeIf(c -> c.getRecipient().equals(contact)));
 					break;
 			}

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

@@ -2,6 +2,7 @@ package envoy.client.ui.controller;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.time.Instant;
 import java.util.concurrent.TimeoutException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -94,7 +95,8 @@ public final class LoginScene {
 		userTextField.requestFocus();
 
 		// Perform automatic login if configured
-		if (config.hasLoginCredentials()) performHandshake(config.getLoginCredentials());
+		if (config.hasLoginCredentials())
+			performHandshake(new LoginCredentials(config.getUser(), config.getPassword(), false, Startup.VERSION, loadLastSync(config.getUser())));
 	}
 
 	@FXML
@@ -108,12 +110,13 @@ public final class LoginScene {
 			new Alert(AlertType.ERROR, "The entered user name is not valid (" + Bounds.CONTACT_NAME_PATTERN + ")").showAndWait();
 			userTextField.getTextField().clear();
 		} else performHandshake(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), registerCheckBox.isSelected(),
-				Startup.VERSION));
+				Startup.VERSION, loadLastSync(userTextField.getTextField().getText())));
 	}
 
 	@FXML
 	private void offlineModeButtonPressed() {
-		attemptOfflineMode(new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), false, Startup.VERSION));
+		attemptOfflineMode(
+				new LoginCredentials(userTextField.getTextField().getText(), passwordField.getText(), false, Startup.VERSION, localDB.getLastSync()));
 	}
 
 	@FXML
@@ -130,6 +133,18 @@ public final class LoginScene {
 		System.exit(0);
 	}
 
+	private Instant loadLastSync(String identifier) {
+		try {
+			localDB.loadUsers();
+			localDB.setUser(localDB.getUsers().get(identifier));
+			localDB.initializeUserStorage();
+			localDB.loadUserData();
+		} catch (Exception e) {
+			// User storage empty, wrong user name etc. -> default lastSync
+		}
+		return localDB.getLastSync();
+	}
+
 	private void performHandshake(LoginCredentials credentials) {
 		try {
 			client.performHandshake(credentials, cacheMap);

client/src/main/java/envoy/client/ui/listcell/MessageControl.java

@@ -3,6 +3,7 @@ package envoy.client.ui.listcell;
 import java.awt.Toolkit;
 import java.awt.datatransfer.StringSelection;
 import java.io.ByteArrayInputStream;
+import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 import java.util.Map;
 import java.util.logging.Level;
@@ -35,11 +36,12 @@ import envoy.util.EnvoyLog;
  */
 public class MessageControl extends Label {
 
-	private static User								client;
+	private static User client;
-	private static final DateTimeFormatter			dateFormat		= DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm");
-	private static final Map<MessageStatus, Image>	statusImages	= IconUtil.loadByEnum(MessageStatus.class, 16);
 
-	private static final Logger logger = EnvoyLog.getLogger(MessageControl.class);
+	private static final DateTimeFormatter			dateFormat		= DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss")
+		.withZone(ZoneId.systemDefault());
+	private static final Map<MessageStatus, Image>	statusImages	= IconUtil.loadByEnum(MessageStatus.class, 16);
+	private static final Logger						logger			= EnvoyLog.getLogger(MessageControl.class);
 
 	/**
 	 *
@@ -68,7 +70,8 @@ public class MessageControl extends Label {
 		if (message.hasAttachment()) {
 			switch (message.getAttachment().getType()) {
 				case PICTURE:
-					vbox.getChildren().add(new ImageView(new Image(new ByteArrayInputStream(message.getAttachment().getData()), 256, 256, true, true)));
+					vbox.getChildren()
+						.add(new ImageView(new Image(new ByteArrayInputStream(message.getAttachment().getData()), 256, 256, true, true)));
 					break;
 				case VIDEO:
 					break;

client/src/main/resources/client.properties

@@ -1,3 +1,4 @@
 server=localhost
 port=8080
-localDB=.\\localDB
+localDB=localDB
+consoleLevelBarrier=FINER

common/.classpath

@@ -8,15 +8,9 @@
 	</classpathentry>
 	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
 		<attributes>
-			<attribute name="test" value="true"/>
 			<attribute name="optional" value="true"/>
 			<attribute name="maven.pomderived" value="true"/>
-		</attributes>
+			<attribute name="test" value="true"/>
-	</classpathentry>
-	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
-		<attributes>
-			<attribute name="maven.pomderived" value="true"/>
-			<attribute name="org.eclipse.jst.component.nondependency" value=""/>
 		</attributes>
 	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-11">
@@ -24,5 +18,10 @@
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
 	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>

common/.project

@@ -1,35 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>envoy-common</name>
+	<name>common</name>
 	<comment></comment>
 	<projects>
 	</projects>
 	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.wst.common.project.facet.core.builder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
 		<buildCommand>
 			<name>org.eclipse.jdt.core.javabuilder</name>
 			<arguments>
 			</arguments>
 		</buildCommand>
-		<buildCommand>
-			<name>org.jboss.tools.jst.web.kb.kbbuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-		<buildCommand>
-			<name>org.jboss.tools.cdi.core.cdibuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-		<buildCommand>
-			<name>org.eclipse.wst.validation.validationbuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
 		<buildCommand>
 			<name>org.eclipse.m2e.core.maven2Builder</name>
 			<arguments>
@@ -37,10 +17,7 @@
 		</buildCommand>
 	</buildSpec>
 	<natures>
-		<nature>org.eclipse.jem.workbench.JavaEMFNature</nature>
-		<nature>org.eclipse.wst.common.modulecore.ModuleCoreNature</nature>
 		<nature>org.eclipse.jdt.core.javanature</nature>
 		<nature>org.eclipse.m2e.core.maven2Nature</nature>
-		<nature>org.eclipse.wst.common.project.facet.core.nature</nature>
 	</natures>
 </projectDescription>

common/.settings/org.eclipse.core.resources.prefs

@@ -1,5 +1,4 @@
 eclipse.preferences.version=1
 encoding//src/main/java=UTF-8
 encoding//src/test/java=UTF-8
-encoding//src/test/resources=UTF-8
 encoding/<project>=UTF-8

common/.settings/org.eclipse.jdt.core.prefs

@@ -9,8 +9,14 @@ org.eclipse.jdt.core.compiler.annotation.nullable=org.eclipse.jdt.annotation.Nul
 org.eclipse.jdt.core.compiler.annotation.nullable.secondary=
 org.eclipse.jdt.core.compiler.annotation.nullanalysis=disabled
 org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.methodParameters=do not generate
 org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
 org.eclipse.jdt.core.compiler.compliance=11
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.doc.comment.support=enabled
 org.eclipse.jdt.core.compiler.problem.APILeak=warning
 org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
@@ -21,10 +27,10 @@ org.eclipse.jdt.core.compiler.problem.deprecation=warning
 org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
 org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled
 org.eclipse.jdt.core.compiler.problem.discouragedReference=warning
-org.eclipse.jdt.core.compiler.problem.emptyStatement=info
+org.eclipse.jdt.core.compiler.problem.emptyStatement=ignore
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
-org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=warning
+org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=ignore
 org.eclipse.jdt.core.compiler.problem.fallthroughCase=ignore
 org.eclipse.jdt.core.compiler.problem.fatalOptionalError=disabled
 org.eclipse.jdt.core.compiler.problem.fieldHiding=ignore
@@ -35,14 +41,27 @@ org.eclipse.jdt.core.compiler.problem.hiddenCatchBlock=warning
 org.eclipse.jdt.core.compiler.problem.includeNullInfoFromAsserts=disabled
 org.eclipse.jdt.core.compiler.problem.incompatibleNonInheritedInterfaceMethod=warning
 org.eclipse.jdt.core.compiler.problem.incompleteEnumSwitch=ignore
-org.eclipse.jdt.core.compiler.problem.indirectStaticAccess=warning
+org.eclipse.jdt.core.compiler.problem.indirectStaticAccess=ignore
+org.eclipse.jdt.core.compiler.problem.invalidJavadoc=info
+org.eclipse.jdt.core.compiler.problem.invalidJavadocTags=enabled
+org.eclipse.jdt.core.compiler.problem.invalidJavadocTagsDeprecatedRef=enabled
+org.eclipse.jdt.core.compiler.problem.invalidJavadocTagsNotVisibleRef=enabled
+org.eclipse.jdt.core.compiler.problem.invalidJavadocTagsVisibility=public
 org.eclipse.jdt.core.compiler.problem.localVariableHiding=ignore
 org.eclipse.jdt.core.compiler.problem.methodWithConstructorName=warning
 org.eclipse.jdt.core.compiler.problem.missingDefaultCase=ignore
 org.eclipse.jdt.core.compiler.problem.missingDeprecatedAnnotation=ignore
 org.eclipse.jdt.core.compiler.problem.missingEnumCaseDespiteDefault=disabled
 org.eclipse.jdt.core.compiler.problem.missingHashCodeMethod=ignore
-org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotation=warning
+org.eclipse.jdt.core.compiler.problem.missingJavadocComments=info
+org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsOverriding=disabled
+org.eclipse.jdt.core.compiler.problem.missingJavadocCommentsVisibility=public
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagDescription=all_standard_tags
+org.eclipse.jdt.core.compiler.problem.missingJavadocTags=info
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagsMethodTypeParameters=disabled
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagsOverriding=disabled
+org.eclipse.jdt.core.compiler.problem.missingJavadocTagsVisibility=public
+org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotation=ignore
 org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotationForInterfaceMethodImplementation=enabled
 org.eclipse.jdt.core.compiler.problem.missingSerialVersion=warning
 org.eclipse.jdt.core.compiler.problem.missingSynchronizedOnInheritedMethod=ignore
@@ -63,12 +82,12 @@ org.eclipse.jdt.core.compiler.problem.potentialNullReference=ignore
 org.eclipse.jdt.core.compiler.problem.potentiallyUnclosedCloseable=ignore
 org.eclipse.jdt.core.compiler.problem.rawTypeReference=warning
 org.eclipse.jdt.core.compiler.problem.redundantNullAnnotation=warning
-org.eclipse.jdt.core.compiler.problem.redundantNullCheck=warning
+org.eclipse.jdt.core.compiler.problem.redundantNullCheck=ignore
 org.eclipse.jdt.core.compiler.problem.redundantSpecificationOfTypeArguments=warning
 org.eclipse.jdt.core.compiler.problem.redundantSuperinterface=warning
 org.eclipse.jdt.core.compiler.problem.reportMethodCanBePotentiallyStatic=ignore
 org.eclipse.jdt.core.compiler.problem.reportMethodCanBeStatic=ignore
-org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
 org.eclipse.jdt.core.compiler.problem.specialParameterHidingField=disabled
 org.eclipse.jdt.core.compiler.problem.staticAccessReceiver=warning
 org.eclipse.jdt.core.compiler.problem.suppressOptionalErrors=disabled
@@ -79,18 +98,18 @@ org.eclipse.jdt.core.compiler.problem.syntheticAccessEmulation=ignore
 org.eclipse.jdt.core.compiler.problem.terminalDeprecation=warning
 org.eclipse.jdt.core.compiler.problem.typeParameterHiding=warning
 org.eclipse.jdt.core.compiler.problem.unavoidableGenericTypeProblems=disabled
-org.eclipse.jdt.core.compiler.problem.uncheckedTypeOperation=warning
+org.eclipse.jdt.core.compiler.problem.uncheckedTypeOperation=ignore
 org.eclipse.jdt.core.compiler.problem.unclosedCloseable=warning
 org.eclipse.jdt.core.compiler.problem.undocumentedEmptyBlock=ignore
 org.eclipse.jdt.core.compiler.problem.unhandledWarningToken=warning
 org.eclipse.jdt.core.compiler.problem.unlikelyCollectionMethodArgumentType=warning
 org.eclipse.jdt.core.compiler.problem.unlikelyCollectionMethodArgumentTypeStrict=disabled
 org.eclipse.jdt.core.compiler.problem.unlikelyEqualsArgumentType=info
-org.eclipse.jdt.core.compiler.problem.unnecessaryElse=warning
+org.eclipse.jdt.core.compiler.problem.unnecessaryElse=ignore
-org.eclipse.jdt.core.compiler.problem.unnecessaryTypeCheck=warning
+org.eclipse.jdt.core.compiler.problem.unnecessaryTypeCheck=ignore
 org.eclipse.jdt.core.compiler.problem.unqualifiedFieldAccess=ignore
 org.eclipse.jdt.core.compiler.problem.unstableAutoModuleName=warning
-org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownException=warning
+org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownException=ignore
 org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionExemptExceptionAndThrowable=enabled
 org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionIncludeDocCommentReference=enabled
 org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionWhenOverriding=disabled
@@ -104,7 +123,7 @@ org.eclipse.jdt.core.compiler.problem.unusedParameterIncludeDocCommentReference=
 org.eclipse.jdt.core.compiler.problem.unusedParameterWhenImplementingAbstract=disabled
 org.eclipse.jdt.core.compiler.problem.unusedParameterWhenOverridingConcrete=disabled
 org.eclipse.jdt.core.compiler.problem.unusedPrivateMember=warning
-org.eclipse.jdt.core.compiler.problem.unusedTypeParameter=warning
+org.eclipse.jdt.core.compiler.problem.unusedTypeParameter=ignore
 org.eclipse.jdt.core.compiler.problem.unusedWarningToken=warning
 org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
 org.eclipse.jdt.core.compiler.release=disabled
@@ -226,7 +245,7 @@ org.eclipse.jdt.core.formatter.insert_new_line_after_annotation_on_type=insert
 org.eclipse.jdt.core.formatter.insert_new_line_after_label=insert
 org.eclipse.jdt.core.formatter.insert_new_line_after_opening_brace_in_array_initializer=do not insert
 org.eclipse.jdt.core.formatter.insert_new_line_after_type_annotation=do not insert
-org.eclipse.jdt.core.formatter.insert_new_line_at_end_of_file_if_missing=do not insert
+org.eclipse.jdt.core.formatter.insert_new_line_at_end_of_file_if_missing=insert
 org.eclipse.jdt.core.formatter.insert_new_line_before_catch_in_try_statement=do not insert
 org.eclipse.jdt.core.formatter.insert_new_line_before_closing_brace_in_array_initializer=do not insert
 org.eclipse.jdt.core.formatter.insert_new_line_before_else_in_if_statement=do not insert
@@ -420,7 +439,7 @@ org.eclipse.jdt.core.formatter.keep_code_block_on_one_line=one_line_if_empty
 org.eclipse.jdt.core.formatter.keep_else_statement_on_same_line=true
 org.eclipse.jdt.core.formatter.keep_empty_array_initializer_on_one_line=false
 org.eclipse.jdt.core.formatter.keep_enum_constant_declaration_on_one_line=one_line_never
-org.eclipse.jdt.core.formatter.keep_enum_declaration_on_one_line=one_line_never
+org.eclipse.jdt.core.formatter.keep_enum_declaration_on_one_line=one_line_if_empty
 org.eclipse.jdt.core.formatter.keep_if_then_body_block_on_one_line=one_line_if_single_item
 org.eclipse.jdt.core.formatter.keep_imple_if_on_one_line=false
 org.eclipse.jdt.core.formatter.keep_lambda_body_block_on_one_line=one_line_always
@@ -431,7 +450,7 @@ org.eclipse.jdt.core.formatter.keep_simple_for_body_on_same_line=false
 org.eclipse.jdt.core.formatter.keep_simple_getter_setter_on_one_line=true
 org.eclipse.jdt.core.formatter.keep_simple_while_body_on_same_line=false
 org.eclipse.jdt.core.formatter.keep_then_statement_on_same_line=true
-org.eclipse.jdt.core.formatter.keep_type_declaration_on_one_line=one_line_never
+org.eclipse.jdt.core.formatter.keep_type_declaration_on_one_line=one_line_if_empty
 org.eclipse.jdt.core.formatter.lineSplit=150
 org.eclipse.jdt.core.formatter.never_indent_block_comments_on_first_column=false
 org.eclipse.jdt.core.formatter.never_indent_line_comments_on_first_column=false

common/.settings/org.eclipse.wst.common.component

@@ -1,37 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?><project-modules id="moduleCoreId" project-version="1.5.0">
-                                    
-    
-    
-    
-    
-    
-    
-    
-    <wb-module deploy-name="envoy-common">
-                                                                        
-        
-        
-        
-        
-        
-        
-        
-        <wb-resource deploy-path="/" source-path="/src/main/java"/>
-                                                                    
-    
-    
-    
-    
-    
-    
-    
-    </wb-module>
-                                
-
-
-
-
-
-
-
-</project-modules>

common/.settings/org.eclipse.wst.common.project.facet.core.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<faceted-project>
-  <installed facet="jst.utility" version="1.0"/>
-  <installed facet="java" version="11"/>
-</faceted-project>

common/.settings/org.eclipse.wst.validation.prefs

@@ -1,2 +0,0 @@
-disabled=06target
-eclipse.preferences.version=1

common/src/main/java/envoy/data/Contact.java

@@ -17,9 +17,10 @@ import java.util.Set;
  */
 public abstract class Contact implements Serializable {
 
-	private final long								id;
+	protected final long								id;
-	private final transient Set<? extends Contact>	contacts;
+	protected final transient Set<? extends Contact>	contacts;
-	private String									name;
+
+	protected String name;
 
 	private static final long serialVersionUID = 0L;
 
@@ -55,19 +56,13 @@ public abstract class Contact implements Serializable {
 	 */
 	public void setName(String name) { this.name = name; }
 
-	/**
-	 * {@inheritDoc}
-	 */
-	@Override
-	public String toString() { return String.format("Contact[id=%d,name=%s, contacts=%s]", id, name, contacts); }
-
 	/**
 	 * Provides a hash code based on the ID of this contact.
 	 * 
 	 * @since Envoy Common v0.1-beta
 	 */
 	@Override
-	public int hashCode() { return Objects.hash(id); }
+	public final int hashCode() { return Objects.hash(id); }
 
 	/**
 	 * Tests equality to another object. If that object is a contact as well,
@@ -77,7 +72,7 @@ public abstract class Contact implements Serializable {
 	 * @return {code true} if both objects are contacts and have identical IDs
 	 */
 	@Override
-	public boolean equals(Object obj) {
+	public final boolean equals(Object obj) {
 		if (this == obj) return true;
 		if (!(obj instanceof Contact)) return false;
 		return id == ((Contact) obj).id;

common/src/main/java/envoy/data/Group.java

@@ -36,6 +36,9 @@ public final class Group extends Contact {
 	 */
 	public Group(long id, String name, Set<User> members) { super(id, name, members); }
 
+	@Override
+	public String toString() { return String.format("Group[id=%d,name=%s,%d member(s)]", id, name, contacts.size()); }
+
 	private void readObject(ObjectInputStream inputStream) throws Exception {
 		inputStream.defaultReadObject();
 		var contacts = Contact.class.getDeclaredField("contacts");
@@ -49,7 +52,6 @@ public final class Group extends Contact {
 		outputStream.writeObject(getContacts());
 	}
 
-	@SuppressWarnings("unchecked")
 	@Override
-	public Set<User> getContacts() { return (Set<User>) super.getContacts(); }
+	public Set<User> getContacts() { return (Set<User>) contacts; }
 }

common/src/main/java/envoy/data/GroupMessage.java

@@ -1,6 +1,6 @@
 package envoy.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.Map;
 
@@ -16,7 +16,7 @@ public final class GroupMessage extends Message {
 
 	private final Map<Long, MessageStatus> memberStatuses;
 
-	private static final long serialVersionUID = 0L;
+	private static final long serialVersionUID = 1L;
 
 	/**
 	 * Initializes a {@link GroupMessage} with values for all of its properties. The
@@ -38,9 +38,9 @@ public final class GroupMessage extends Message {
 	 * @param forwarded      whether this message was forwarded
 	 * @param memberStatuses a map of all members and their status according to this
 	 *                       {@link GroupMessage}
-	 * @since Envoy Common v0.1-beta
+	 * @since Envoy Common v0.2-beta
 	 */
-	GroupMessage(long id, long senderID, long groupID, LocalDateTime creationDate, LocalDateTime receivedDate, LocalDateTime readDate, String text,
+	GroupMessage(long id, long senderID, long groupID, Instant creationDate, Instant receivedDate, Instant readDate, String text,
 			Attachment attachment, MessageStatus status, boolean forwarded, Map<Long, MessageStatus> memberStatuses) {
 		super(id, senderID, groupID, creationDate, receivedDate, readDate, text, attachment, status, forwarded);
 		this.memberStatuses = memberStatuses;
@@ -55,10 +55,10 @@ public final class GroupMessage extends Message {
 		setStatus(Collections.min(memberStatuses.values()));
 		switch (getStatus()) {
 			case RECEIVED:
-				setReceivedDate(LocalDateTime.now());
+				setReceivedDate(Instant.now());
 				break;
 			case READ:
-				setReadDate(LocalDateTime.now());
+				setReadDate(Instant.now());
 				break;
 		}
 	}

common/src/main/java/envoy/data/LoginCredentials.java

@@ -1,6 +1,7 @@
 package envoy.data;
 
 import java.io.Serializable;
+import java.time.Instant;
 
 /**
  * Contains a {@link User}'s login / registration information as well as the
@@ -17,8 +18,9 @@ public final class LoginCredentials implements Serializable {
 
 	private final String	identifier, password, clientVersion;
 	private final boolean	registration;
+	private final Instant	lastSync;
 
-	private static final long serialVersionUID = 2;
+	private static final long serialVersionUID = 3;
 
 	/**
 	 * Initializes login credentials for a handshake.
@@ -28,18 +30,24 @@ public final class LoginCredentials implements Serializable {
 	 * @param registration  signifies that these credentials are used for user
 	 *                      registration instead of user login
 	 * @param clientVersion the version of the client sending these credentials
-	 * @since Envoy Common v0.1-beta
+	 * @param lastSync      the time stamp of the last synchronization
+	 * @since Envoy Common v0.2-beta
 	 */
-	public LoginCredentials(String identifier, String password, boolean registration, String clientVersion) {
+	public LoginCredentials(String identifier, String password, boolean registration, String clientVersion, Instant lastSync) {
 		this.identifier		= identifier;
 		this.password		= password;
 		this.registration	= registration;
 		this.clientVersion	= clientVersion;
+		this.lastSync		= lastSync;
 	}
 
 	@Override
 	public String toString() {
-		return String.format("LoginCredentials[identifier=%s,registration=%b,clientVersion=%s]", identifier, registration, clientVersion);
+		return String.format("LoginCredentials[identifier=%s,registration=%b,clientVersion=%s,lastSync=%s]",
+				identifier,
+				registration,
+				clientVersion,
+				lastSync);
 	}
 
 	/**
@@ -66,4 +74,10 @@ public final class LoginCredentials implements Serializable {
 	 * @since Envoy Common v0.1-beta
 	 */
 	public String getClientVersion() { return clientVersion; }
+
+	/**
+	 * @return the time stamp of the last synchronization
+	 * @since Envoy Common v0.2-beta
+	 */
+	public Instant getLastSync() { return lastSync; }
 }

common/src/main/java/envoy/data/Message.java

@@ -1,8 +1,7 @@
 package envoy.data;
 
 import java.io.Serializable;
-import java.time.LocalDateTime;
+import java.time.Instant;
-import java.time.format.DateTimeFormatter;
 
 /**
  * Represents a unique message with a unique, numeric ID. Further metadata
@@ -50,14 +49,14 @@ public class Message implements Serializable {
 
 	private final long			id, senderID, recipientID;
 	private final boolean		forwarded;
-	private final LocalDateTime	creationDate;
+	private final Instant		creationDate;
 	private final String		text;
 	private final Attachment	attachment;
 
-	private LocalDateTime	receivedDate, readDate;
+	private Instant			receivedDate, readDate;
 	private MessageStatus	status;
 
-	private static final long serialVersionUID = 1L;
+	private static final long serialVersionUID = 2L;
 
 	/**
 	 * Initializes a {@link Message} with values for all of its properties. The use
@@ -75,9 +74,9 @@ public class Message implements Serializable {
 	 * @param attachment   the attachment of the message, if present
 	 * @param status       the current {@link MessageStatus} of the message
 	 * @param forwarded    whether this message was forwarded
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	Message(long id, long senderID, long recipientID, LocalDateTime creationDate, LocalDateTime receivedDate, LocalDateTime readDate, String text,
+	Message(long id, long senderID, long recipientID, Instant creationDate, Instant receivedDate, Instant readDate, String text,
 			Attachment attachment, MessageStatus status, boolean forwarded) {
 		this.id				= id;
 		this.senderID		= senderID;
@@ -115,7 +114,7 @@ public class Message implements Serializable {
 				id,
 				senderID,
 				recipientID,
-				DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss").format(creationDate),
+				creationDate,
 				status,
 				text,
 				forwarded,
@@ -142,34 +141,34 @@ public class Message implements Serializable {
 
 	/**
 	 * @return the date at which this message was created
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public LocalDateTime getCreationDate() { return creationDate; }
+	public Instant getCreationDate() { return creationDate; }
 
 	/**
 	 * @return the date at which the message has been received by the sender
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public LocalDateTime getReceivedDate() { return receivedDate; }
+	public Instant getReceivedDate() { return receivedDate; }
 
 	/**
 	 * @param receivedDate the date at which the message has been received by the
 	 *                     sender
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public void setReceivedDate(LocalDateTime receivedDate) { this.receivedDate = receivedDate; }
+	public void setReceivedDate(Instant receivedDate) { this.receivedDate = receivedDate; }
 
 	/**
 	 * @return the date at which the message has been read by the sender
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public LocalDateTime getReadDate() { return readDate; }
+	public Instant getReadDate() { return readDate; }
 
 	/**
 	 * @param readDate at which the message has been read by the sender
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public void setReadDate(LocalDateTime readDate) { this.readDate = readDate; }
+	public void setReadDate(Instant readDate) { this.readDate = readDate; }
 
 	/**
 	 * @return the text content of this message

common/src/main/java/envoy/data/MessageBuilder.java

@@ -1,6 +1,6 @@
 package envoy.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -23,7 +23,7 @@ public class MessageBuilder {
 
 	// Properties with default values
 	private long					id;
-	private LocalDateTime			creationDate, receivedDate, readDate;
+	private Instant					creationDate, receivedDate, readDate;
 	private String					text;
 	private Attachment				attachment;
 	private Message.MessageStatus	status;
@@ -70,7 +70,7 @@ public class MessageBuilder {
 	public MessageBuilder(Message msg, long recipientID, IDGenerator iDGenerator) {
 		this(msg.getRecipientID(), recipientID, iDGenerator.next());
 		this.attachment		= msg.getAttachment();
-		this.creationDate	= LocalDateTime.now();
+		this.creationDate	= Instant.now();
 		this.forwarded		= true;
 		this.text			= msg.getText();
 		this.status			= MessageStatus.WAITING;
@@ -83,7 +83,7 @@ public class MessageBuilder {
 	 * <table border="1">
 	 * <tr>
 	 * <td>{@code date}</td>
-	 * <td>{@code LocalDateTime.now()} and {@code null} for {@code receivedDate} and
+	 * <td>{@code Instant.now()} and {@code null} for {@code receivedDate} and
 	 * {@code readDate}</td>
 	 * <tr>
 	 * <tr>
@@ -113,8 +113,8 @@ public class MessageBuilder {
 	 * <br>
 	 * <table border="1">
 	 * <tr>
-	 * <td>{@code date}</td>
+	 * <td>{@code time stamp}</td>
-	 * <td>{@code new Date()}</td>
+	 * <td>{@code Instant.now()}</td>
 	 * <tr>
 	 * <tr>
 	 * <td>{@code text}</td>
@@ -140,8 +140,8 @@ public class MessageBuilder {
 	 * <br>
 	 * <table border="1">
 	 * <tr>
-	 * <td>{@code date}</td>
+	 * <td>{@code time stamp}</td>
-	 * <td>{@code new Date()}</td>
+	 * <td>{@code Instant.now()}</td>
 	 * <tr>
 	 * <tr>
 	 * <td>{@code text}</td>
@@ -162,7 +162,7 @@ public class MessageBuilder {
 	}
 
 	private void supplyDefaults() {
-		if (creationDate == null) creationDate = LocalDateTime.now();
+		if (creationDate == null) creationDate = Instant.now();
 		if (text == null) text = "";
 		if (status == null) status = MessageStatus.WAITING;
 	}
@@ -170,9 +170,9 @@ public class MessageBuilder {
 	/**
 	 * @param creationDate the creation date of the {@link Message} to create
 	 * @return this {@link MessageBuilder}
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public MessageBuilder setCreationDate(LocalDateTime creationDate) {
+	public MessageBuilder setCreationDate(Instant creationDate) {
 		this.creationDate = creationDate;
 		return this;
 	}
@@ -180,9 +180,9 @@ public class MessageBuilder {
 	/**
 	 * @param receivedDate the received date of the {@link Message} to create
 	 * @return this {@link MessageBuilder}
-	 * @since Envoy Common v0.1-beta
+	 * @since Envoy Common v0.2-beta
 	 */
-	public MessageBuilder setReceivedDate(LocalDateTime receivedDate) {
+	public MessageBuilder setReceivedDate(Instant receivedDate) {
 		this.receivedDate = receivedDate;
 		return this;
 	}
@@ -190,9 +190,9 @@ public class MessageBuilder {
 	/**
 	 * @param readDate the read date of the {@link Message} to create
 	 * @return this {@link MessageBuilder}
-	 * @since Envoy Common v0.1-beta
+	 * @since Envoy Common v0.2-beta
 	 */
-	public MessageBuilder setReadDate(LocalDateTime readDate) {
+	public MessageBuilder setReadDate(Instant readDate) {
 		this.readDate = readDate;
 		return this;
 	}

common/src/main/java/envoy/data/User.java

@@ -99,7 +99,9 @@ public final class User extends Contact {
 	}
 
 	@Override
-	public String toString() { return String.format("User[id=%d,name=%s,status=%s,contacts=%s]", getID(), getName(), status, getContacts()); }
+	public String toString() {
+		return String.format("User[id=%d,name=%s,status=%s", id, name, status) + (contacts.isEmpty() ? "]" : "," + contacts.size() + " contact(s)]");
+	}
 
 	/**
 	 * @return the current status of this user

common/src/main/java/envoy/event/EventBus.java

@@ -53,7 +53,6 @@ public class EventBus {
 	 * @param handler    the event handler to register
 	 * @since Envoy v0.2-alpha
 	 */
-	@SuppressWarnings("unchecked")
 	public <T extends Event<?>> void register(Class<T> eventClass, Consumer<T> handler) {
 		if (!handlers.containsKey(eventClass)) handlers.put(eventClass, new ArrayList<>());
 		handlers.get(eventClass).add((Consumer<Event<?>>) handler);

common/src/main/java/envoy/event/GroupMessageStatusChange.java

@@ -1,6 +1,6 @@
 package envoy.event;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 
 import envoy.data.GroupMessage;
 import envoy.data.Message.MessageStatus;
@@ -27,9 +27,9 @@ public class GroupMessageStatusChange extends MessageStatusChange {
 	 * @param date     the date at which the MessageStatus change occurred for
 	 *                 this specific member
 	 * @param memberID the ID of the group member that caused the status change
-	 * @since Envoy Common v0.1-beta
+	 * @since Envoy Common v0.2-beta
 	 */
-	public GroupMessageStatusChange(long id, MessageStatus status, LocalDateTime date, long memberID) {
+	public GroupMessageStatusChange(long id, MessageStatus status, Instant date, long memberID) {
 		super(id, status, date);
 		this.memberID = memberID;
 	}

common/src/main/java/envoy/event/MessageStatusChange.java

@@ -1,6 +1,6 @@
 package envoy.event;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 
 import envoy.data.Message;
 
@@ -14,8 +14,8 @@ import envoy.data.Message;
  */
 public class MessageStatusChange extends Event<Message.MessageStatus> {
 
-	private final long	id;
+	private final long		id;
-	private final LocalDateTime	date;
+	private final Instant	date;
 
 	private static final long serialVersionUID = 0L;
 
@@ -26,9 +26,9 @@ public class MessageStatusChange extends Event<Message.MessageStatus> {
 	 * @param status the status of the {@link Message} this event is related
 	 *               to
 	 * @param date   the date at which the MessageStatus change occurred
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public MessageStatusChange(long id, Message.MessageStatus status, LocalDateTime date) {
+	public MessageStatusChange(long id, Message.MessageStatus status, Instant date) {
 		super(status);
 		this.id		= id;
 		this.date	= date;
@@ -40,7 +40,7 @@ public class MessageStatusChange extends Event<Message.MessageStatus> {
 	 * @param message the message from which to build the event
 	 * @since Envoy Common v0.2-alpha
 	 */
-	public MessageStatusChange(Message message) { this(message.getID(), message.getStatus(), LocalDateTime.now()); }
+	public MessageStatusChange(Message message) { this(message.getID(), message.getStatus(), Instant.now()); }
 
 	/**
 	 * @return the ID of the {@link Message} this event is related to
@@ -50,9 +50,9 @@ public class MessageStatusChange extends Event<Message.MessageStatus> {
 
 	/**
 	 * @return the date at which the status change occurred
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.2-beta
 	 */
-	public LocalDateTime getDate() { return date; }
+	public Instant getDate() { return date; }
 
 	@Override
 	public String toString() { return String.format("MessageStatusChange[id=%d,status=%s,date=%s]", id, value, date); }

server/.project

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>envoy-server-standalone</name>
+	<name>server</name>
 	<comment></comment>
 	<projects>
 	</projects>
@@ -35,6 +35,5 @@
 		<nature>org.eclipse.jdt.core.javanature</nature>
 		<nature>org.eclipse.m2e.core.maven2Nature</nature>
 		<nature>org.eclipse.wst.common.project.facet.core.nature</nature>
-		<nature>org.hibernate.eclipse.console.hibernateNature</nature>
 	</natures>
 </projectDescription>

server/src/main/java/envoy/server/data/Contact.java

@@ -1,6 +1,6 @@
 package envoy.server.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Set;
 
 import javax.persistence.*;
@@ -28,7 +28,7 @@ public abstract class Contact {
 	protected String	name;
 
 	@Column(name = "creation_date")
-	private LocalDateTime creationDate;
+	private Instant creationDate;
 
 	@ManyToMany(fetch = FetchType.EAGER)
 	protected Set<Contact> contacts;
@@ -92,16 +92,16 @@ public abstract class Contact {
 
 	/**
 	 * @return the creationDate
-	 * @since Envoy Server Standalone v0.1-beta
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getCreationDate() { return creationDate; }
+	public Instant getCreationDate() { return creationDate; }
 
 	/**
 	 * @param creationDate the creationDate to set
-	 * @since Envoy Server Standalone v0.1-beta
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public void setCreationDate(LocalDateTime creationDate) { this.creationDate = creationDate; }
+	public void setCreationDate(Instant creationDate) { this.creationDate = creationDate; }
 
 	@Override
-	public String toString() { return String.format("%s[id=%d,name=%s, %d contact(s)]", getClass().getSimpleName(), id, name, contacts.size()); }
+	public String toString() { return String.format("%s[id=%d,name=%s,%d contact(s)]", getClass().getSimpleName(), id, name, contacts.size()); }
 }

server/src/main/java/envoy/server/data/GroupMessage.java

@@ -1,6 +1,6 @@
 package envoy.server.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -19,10 +19,10 @@ import envoy.data.Group;
 @Entity
 @NamedQuery(
 	name = GroupMessage.getPendingGroupMsg,
-	query = "SELECT m FROM GroupMessage m JOIN m.memberMessageStatus s WHERE (KEY(s) = :userId) AND ((m.creationDate > :lastSeen)"
+	query = "SELECT m FROM GroupMessage m JOIN m.memberMessageStatus s WHERE KEY(s) = :userId AND (m.creationDate > :lastSeen "
-			+ "OR ((m.status = envoy.data.Message$MessageStatus.RECEIVED) AND (m.receivedDate > :lastSeen))"
+			+ "OR m.status = envoy.data.Message$MessageStatus.RECEIVED AND m.receivedDate > :lastSeen "
-			+ "OR ((m.status = envoy.data.Message$MessageStatus.READ) AND (m.readDate > :lastSeen))"
+			+ "OR m.status = envoy.data.Message$MessageStatus.READ AND m.readDate > :lastSeen "
-			+ "OR ((m.lastStatusChangeDate > :lastSeen)))"
+			+ "OR m.lastStatusChangeDate > :lastSeen)"
 )
 public class GroupMessage extends Message {
 
@@ -39,7 +39,7 @@ public class GroupMessage extends Message {
 	private Map<Long, envoy.data.Message.MessageStatus> memberMessageStatus;
 
 	@Column(name = "last_status_change_date")
-	protected LocalDateTime lastStatusChangeDate;
+	protected Instant lastStatusChangeDate;
 
 	/**
 	 * The constructor for a database object.
@@ -55,9 +55,9 @@ public class GroupMessage extends Message {
 	 *                             into a
 	 *                             database {@link GroupMessage}
 	 * @param lastStatusChangeDate the time stamp to set
-	 * @since Envoy Server Standalone v0.1-beta
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public GroupMessage(envoy.data.GroupMessage groupMessage, LocalDateTime lastStatusChangeDate) {
+	public GroupMessage(envoy.data.GroupMessage groupMessage, Instant lastStatusChangeDate) {
 		super(groupMessage);
 		memberMessageStatus			= groupMessage.getMemberStatuses();
 		this.lastStatusChangeDate	= lastStatusChangeDate;
@@ -92,13 +92,13 @@ public class GroupMessage extends Message {
 
 	/**
 	 * @return the date at which one of the member statuses changed last
-	 * @since Envoy Server Standalone v0.1-beta
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getLastStatusChangeDate() { return lastStatusChangeDate; }
+	public Instant getLastStatusChangeDate() { return lastStatusChangeDate; }
 
 	/**
 	 * @param date the date to set
-	 * @since Envoy Server Standalone v0.1-beta
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public void setLastStatusChangeDate(LocalDateTime date) { lastStatusChangeDate = date; }
+	public void setLastStatusChangeDate(Instant date) { lastStatusChangeDate = date; }
 }

server/src/main/java/envoy/server/data/Message.java

@@ -2,7 +2,7 @@ package envoy.server.data;
 
 import static envoy.data.Message.MessageStatus.*;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 
 import javax.persistence.*;
 
@@ -12,11 +12,15 @@ import envoy.data.Message.MessageStatus;
 import envoy.data.MessageBuilder;
 
 /**
- * This class serves as a way to let Hibernate communicate with the server
+ * This JPA entity, which will be referred to as database message, stores the
- * without bringing the dependency of JPA/Hibernate into the client.<br>
+ * information contained inside a {@link envoy.data.Message} inside the
- * It will be referenced as "database message" to clarify between the different
+ * database, while having a slightly different data layout.
- * message objects.<br>
+ * <p>
- * <br>
+ * A message can be converted to a database message by using the
+ * {@link Message#Message(envoy.data.Message)} constructor. A database message
+ * can be converted to a regular message using the {@link Message#toCommon()}
+ * method. In both cases, the objects will not contain references to each other.
+ * <p>
  * Project: <strong>envoy-server-standalone</strong><br>
  * File: <strong>Message.java</strong><br>
  * Created: <strong>02.01.2020</strong><br>
@@ -29,9 +33,14 @@ import envoy.data.MessageBuilder;
 @Inheritance(strategy = InheritanceType.SINGLE_TABLE)
 @NamedQuery(
 	name = Message.getPending,
-	query = "SELECT m FROM Message m WHERE (m.recipient = :user AND m.status = envoy.data.Message$MessageStatus.SENT) "
+	query = "SELECT m FROM Message m WHERE "
-			+ "OR (m.sender = :user) AND ((m.status = envoy.data.Message$MessageStatus.RECEIVED) AND (m.receivedDate > :lastSeen)"
+			// Send to or by the user before last seen
-			+ "OR (m.status = envoy.data.Message$MessageStatus.READ) AND (m.readDate > :lastSeen))"
+			+ "(m.sender = :user OR m.recipient = :user) AND m.creationDate > :lastSeen "
+			// SENT to the user
+			+ "OR m.recipient = :user AND m.status = envoy.data.Message$MessageStatus.SENT "
+			// Sent by the user and RECEIVED / READ after last seen
+			+ "OR m.sender = :user AND (m.status = envoy.data.Message$MessageStatus.RECEIVED AND m.receivedDate > :lastSeen "
+			+ "OR m.status = envoy.data.Message$MessageStatus.READ AND m.readDate > :lastSeen)"
 )
 public class Message {
 
@@ -55,13 +64,13 @@ public class Message {
 	protected Contact recipient;
 
 	@Column(name = "creation_date")
-	protected LocalDateTime creationDate;
+	protected Instant creationDate;
 
 	@Column(name = "received_date")
-	protected LocalDateTime receivedDate;
+	protected Instant receivedDate;
 
 	@Column(name = "read_date")
-	protected LocalDateTime readDate;
+	protected Instant readDate;
 
 	protected String							text;
 	protected envoy.data.Message.MessageStatus	status;
@@ -107,17 +116,14 @@ public class Message {
 	 *         message
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public envoy.data.Message toCommon() {
+	public envoy.data.Message toCommon() { return prepareBuilder().build(); }
-		return prepareBuilder().build();
-	}
 
 	/**
 	 * @return a message builder containing the state of this message
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
 	MessageBuilder prepareBuilder() {
-		var builder = new MessageBuilder(sender.getID(), recipient.getID(), id).setText(
+		var builder = new MessageBuilder(sender.getID(), recipient.getID(), id).setText(text)
-				text)
 			.setCreationDate(creationDate)
 			.setReceivedDate(receivedDate)
 			.setReadDate(readDate)
@@ -134,7 +140,7 @@ public class Message {
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
 	public void received() {
-		receivedDate	= LocalDateTime.now();
+		receivedDate	= Instant.now();
 		status			= RECEIVED;
 	}
 
@@ -145,7 +151,7 @@ public class Message {
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
 	public void read() {
-		readDate	= LocalDateTime.now();
+		readDate	= Instant.now();
 		status		= READ;
 	}
 
@@ -190,43 +196,43 @@ public class Message {
 
 	/**
 	 * @return the date at which a {link envoy.data.Message} has been created
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getCreationDate() { return creationDate; }
+	public Instant getCreationDate() { return creationDate; }
 
 	/**
 	 * @param creationDate the creation date to set
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 * @see Message#getCreationDate()
 	 */
-	public void setCreationDate(LocalDateTime creationDate) { this.creationDate = creationDate; }
+	public void setCreationDate(Instant creationDate) { this.creationDate = creationDate; }
 
 	/**
 	 * @return the date at which a {link envoy.data.Message} has been received by
 	 *         the server
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getReceivedDate() { return receivedDate; }
+	public Instant getReceivedDate() { return receivedDate; }
 
 	/**
 	 * @param receivedDate the received date to set
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 * @see Message#getReceivedDate()
 	 */
-	public void setReceivedDate(LocalDateTime receivedDate) { this.receivedDate = receivedDate; }
+	public void setReceivedDate(Instant receivedDate) { this.receivedDate = receivedDate; }
 
 	/**
 	 * @return the date at which a {link envoy.data.Message} has been read
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getReadDate() { return readDate; }
+	public Instant getReadDate() { return readDate; }
 
 	/**
 	 * @param readDate the read date to set
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 * @see Message#getReadDate()
 	 */
-	public void setReadDate(LocalDateTime readDate) { this.readDate = readDate; }
+	public void setReadDate(Instant readDate) { this.readDate = readDate; }
 
 	/**
 	 * @return the status of a {link envoy.data.Message}

server/src/main/java/envoy/server/data/PersistenceManager.java

@@ -1,6 +1,6 @@
 package envoy.server.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.List;
 
 import javax.persistence.EntityManager;
@@ -38,7 +38,7 @@ public class PersistenceManager {
 				.getOnlineUsers()
 				.stream()
 				.map(this::getUserByID)
-				.forEach(user -> { user.setStatus(UserStatus.OFFLINE); user.setLastSeen(LocalDateTime.now()); entityManager.merge(user); });
+				.forEach(user -> { user.setStatus(UserStatus.OFFLINE); user.setLastSeen(Instant.now()); entityManager.merge(user); });
 			transaction.commit();
 		}));
 	}
@@ -182,31 +182,29 @@ public class PersistenceManager {
 	 * Returns all messages received while being offline or the ones that have
 	 * changed.
 	 *
-	 * @param user the user who wants to receive his unread messages
+	 * @param user     the user who wants to receive his unread messages
+	 * @param lastSync the time stamp of the last synchronization
 	 * @return all messages that the client does not yet have (unread messages)
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public List<Message> getPendingMessages(User user) {
+	public List<Message> getPendingMessages(User user, Instant lastSync) {
-		return entityManager
+		return entityManager.createNamedQuery(Message.getPending).setParameter("user", user).setParameter("lastSeen", lastSync).getResultList();
-			.createNamedQuery(Message.getPending)
-			.setParameter("user", user)
-			.setParameter("lastSeen", user.getLastSeen())
-			.getResultList();
 	}
 
 	/**
 	 * Returns all groupMessages received while being offline or the ones that have
 	 * changed.
 	 *
-	 * @param user the user who wants to receive his unread groupMessages
+	 * @param user     the user who wants to receive his unread groupMessages
+	 * @param lastSync the time stamp of the last synchronization
 	 * @return all groupMessages that the client does not yet have (unread
 	 *         groupMessages)
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public List<GroupMessage> getPendingGroupMessages(User user) {
+	public List<GroupMessage> getPendingGroupMessages(User user, Instant lastSync) {
 		return entityManager.createNamedQuery(GroupMessage.getPendingGroupMsg)
 			.setParameter("userId", user.getID())
-			.setParameter("lastSeen", user.getLastSeen())
+			.setParameter("lastSeen", lastSync)
 			.getResultList();
 	}
 
@@ -221,8 +219,7 @@ public class PersistenceManager {
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
 	public List<User> searchUsers(String searchPhrase, long userId) {
-		return entityManager.createNamedQuery(
+		return entityManager.createNamedQuery(User.searchByName)
-				User.searchByName)
 			.setParameter("searchPhrase", searchPhrase + "%")
 			.setParameter("context", getUserByID(userId))
 			.getResultList();

server/src/main/java/envoy/server/data/User.java

@@ -1,6 +1,6 @@
 package envoy.server.data;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -66,7 +66,7 @@ public class User extends Contact {
 	private String passwordHash;
 
 	@Column(name = "last_seen")
-	private LocalDateTime lastSeen;
+	private Instant lastSeen;
 
 	private UserStatus status;
 
@@ -92,15 +92,15 @@ public class User extends Contact {
 
 	/**
 	 * @return the last date the user has been online
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public LocalDateTime getLastSeen() { return lastSeen; }
+	public Instant getLastSeen() { return lastSeen; }
 
 	/**
 	 * @param lastSeen the latest date at which the user has been online to set
-	 * @since Envoy Server Standalone v0.1-alpha
+	 * @since Envoy Server Standalone v0.2-beta
 	 */
-	public void setLastSeen(LocalDateTime lastSeen) { this.lastSeen = lastSeen; }
+	public void setLastSeen(Instant lastSeen) { this.lastSeen = lastSeen; }
 
 	/**
 	 * @return the status

server/src/main/java/envoy/server/net/ConnectionManager.java

@@ -1,6 +1,6 @@
 package envoy.server.net;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.*;
 import java.util.stream.Collectors;
 
@@ -52,7 +52,7 @@ public class ConnectionManager implements ISocketIdListener {
 			// Notify contacts of this users offline-going
 			envoy.server.data.User user = PersistenceManager.getInstance().getUserByID(getUserIDBySocketID(socketID));
 			user.setStatus(UserStatus.OFFLINE);
-			user.setLastSeen(LocalDateTime.now());
+			user.setLastSeen(Instant.now());
 			UserStatusChangeProcessor.updateUserStatus(user);
 
 			// Remove the socket

server/src/main/java/envoy/server/processors/GroupMessageProcessor.java

@@ -2,7 +2,7 @@ package envoy.server.processors;
 
 import static envoy.data.Message.MessageStatus.*;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.logging.Logger;
 
@@ -56,7 +56,7 @@ public class GroupMessageProcessor implements ObjectProcessor<GroupMessage> {
 				groupMessage);
 
 		try {
-			PersistenceManager.getInstance().addMessage(new envoy.server.data.GroupMessage(groupMessage, LocalDateTime.now()));
+			PersistenceManager.getInstance().addMessage(new envoy.server.data.GroupMessage(groupMessage, Instant.now()));
 		} catch (EntityExistsException e) {
 			logger.warning("Received a groupMessage with an ID that already exists");
 		}

server/src/main/java/envoy/server/processors/GroupMessageStatusChangeProcessor.java

@@ -2,7 +2,7 @@ package envoy.server.processors;
 
 import static envoy.data.Message.MessageStatus.READ;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -42,7 +42,7 @@ public class GroupMessageStatusChangeProcessor implements ObjectProcessor<GroupM
 
 		// Apply the status change
 		gmsg.getMemberMessageStatus().replace(statusChange.getMemberID(), statusChange.get());
-		gmsg.setLastStatusChangeDate(LocalDateTime.now());
+		gmsg.setLastStatusChangeDate(Instant.now());
 
 		// Notifying the other members about the status change
 		final var userID = connectionManager.getUserIDBySocketID(socketID);
@@ -59,7 +59,7 @@ public class GroupMessageStatusChangeProcessor implements ObjectProcessor<GroupM
 
 			// Notify online members about the status change
 			writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
-					new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), LocalDateTime.now()));
+					new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), Instant.now()));
 		}
 		persistenceManager.updateMessage(gmsg);
 	}

server/src/main/java/envoy/server/processors/LoginCredentialProcessor.java

@@ -4,7 +4,7 @@ import static envoy.data.Message.MessageStatus.*;
 import static envoy.data.User.UserStatus.ONLINE;
 import static envoy.event.HandshakeRejection.*;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
@@ -47,7 +47,7 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 	@Override
 	public void process(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) {
 
-		// Cache this write proxy for user-independant notifications
+		// Cache this write proxy for user-independent notifications
 		UserStatusChangeProcessor.setWriteProxy(writeProxy);
 
 		if (!VersionUtil.verifyCompatibility(credentials.getClientVersion())) {
@@ -98,7 +98,7 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 				// Creation of a new user
 				user = new User();
 				user.setName(credentials.getIdentifier());
-				user.setLastSeen(LocalDateTime.now());
+				user.setLastSeen(Instant.now());
 				user.setStatus(ONLINE);
 				user.setPasswordHash(PasswordUtil.hash(credentials.getPassword()));
 				user.setContacts(new HashSet<>());
@@ -114,16 +114,17 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 		user.setStatus(ONLINE);
 		UserStatusChangeProcessor.updateUserStatus(user);
 
-		// Complete the handshake
+		final var pendingMessages = PersistenceManager.getInstance().getPendingMessages(user, credentials.getLastSync());
-		writeProxy.write(socketID, user.toCommon());
-
-		final var pendingMessages = PersistenceManager.getInstance().getPendingMessages(user);
 		pendingMessages.removeIf(GroupMessage.class::isInstance);
 		logger.fine("Sending " + pendingMessages.size() + " pending messages to " + user + "...");
 
 		for (var msg : pendingMessages) {
 			final var msgCommon = msg.toCommon();
-			if (msg.getStatus() == SENT) {
+			if (msg.getCreationDate().isAfter(credentials.getLastSync())) {
+
+				// Sync without side effects
+				writeProxy.write(socketID, msgCommon);
+			} else if (msg.getStatus() == SENT) {
 
 				// Send the message
 				writeProxy.write(socketID, msgCommon);
@@ -138,42 +139,46 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 			} else writeProxy.write(socketID, new MessageStatusChange(msgCommon));
 		}
 
-		List<GroupMessage> pendingGroupMessages = PersistenceManager.getInstance().getPendingGroupMessages(user);
+		List<GroupMessage> pendingGroupMessages = PersistenceManager.getInstance().getPendingGroupMessages(user, credentials.getLastSync());
 		logger.fine("Sending " + pendingGroupMessages.size() + " pending group messages to " + user + "...");
 
 		for (var gmsg : pendingGroupMessages) {
 			final var gmsgCommon = gmsg.toCommon();
 
 			// Deliver the message to the user if he hasn't received it yet
-			if (gmsg.getMemberMessageStatus().get(user.getID()) == SENT) {
+			if (gmsg.getCreationDate().isAfter(credentials.getLastSync()) || gmsg.getMemberMessageStatus().get(user.getID()) == SENT) {
-				gmsg.getMemberMessageStatus().replace(user.getID(), RECEIVED);
+				if (gmsg.getMemberMessageStatus().replace(user.getID(), RECEIVED) != RECEIVED) {
 
-				gmsg.setLastStatusChangeDate(LocalDateTime.now());
+					gmsg.setLastStatusChangeDate(Instant.now());
 
-				writeProxy.write(socketID, gmsgCommon);
+					writeProxy.write(socketID, gmsgCommon);
 
-				// Notify all online group members about the status change
+					// Notify all online group members about the status change
-				writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
-						new GroupMessageStatusChange(gmsg.getID(), RECEIVED, LocalDateTime
-							.now(),
-								connectionManager.getUserIDBySocketID(socketID)));
-
-				if (Collections.min(gmsg.getMemberMessageStatus().values()) == RECEIVED) {
-					gmsg.received();
-
-					// Notify online members about the status change
 					writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
-							new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), LocalDateTime.now()));
+							new GroupMessageStatusChange(gmsg.getID(), RECEIVED, Instant.now(), connectionManager.getUserIDBySocketID(socketID)));
-				}
 
-				PersistenceManager.getInstance().updateMessage(gmsg);
+					if (Collections.min(gmsg.getMemberMessageStatus().values()) == RECEIVED) {
+						gmsg.received();
+
+						// Notify online members about the status change
+						writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
+								new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), Instant.now()));
+					}
+
+					PersistenceManager.getInstance().updateMessage(gmsg);
+				} else {
+
+					// Just send the message without updating if it was received in the past
+					writeProxy.write(socketID, gmsgCommon);
+				}
 			} else {
 
 				// Sending group message status changes
 				if (gmsg.getStatus() == SENT && gmsg.getLastStatusChangeDate().isAfter(gmsg.getCreationDate())
 						|| gmsg.getStatus() == RECEIVED && gmsg.getLastStatusChangeDate().isAfter(gmsg.getReceivedDate())) {
-					gmsg.getMemberMessageStatus().forEach((memberID, memberStatus) -> 
+					gmsg.getMemberMessageStatus()
-					writeProxy.write(socketID, new GroupMessageStatusChange(gmsg.getID(), memberStatus, gmsg.getLastStatusChangeDate(), memberID)));
+						.forEach((memberID, memberStatus) -> writeProxy.write(socketID,
+								new GroupMessageStatusChange(gmsg.getID(), memberStatus, gmsg.getLastStatusChangeDate(), memberID)));
 				}
 
 				// Deliver just a status change instead of the whole message
@@ -182,6 +187,9 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 					writeProxy.write(socketID, new MessageStatusChange(gmsgCommon));
 			}
 		}
+
+		// Complete the handshake
+		writeProxy.write(socketID, user.toCommon());
 	}
 
 	@Override