Merge pull request #46 from informatik-ag-ngl/f/groupMessages

Group Messages

src/main/java/envoy/server/Startup.java

@@ -62,8 +62,10 @@ public class Startup {
 		final Server server = new Server(8080, ObjectMessageReader::new,
 				new ObjectMessageProcessor(Set.of(new LoginCredentialProcessor(),
 						new MessageProcessor(),
+						new GroupMessageProcessor(),
 						new GroupCreationProcessor(),
 						new MessageStatusChangeProcessor(),
+						new GroupMessageStatusChangeProcessor(),
 						new UserStatusChangeProcessor(),
 						new IDGeneratorRequestProcessor(),
 						new ContactSearchProcessor(),

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

@@ -1,6 +1,7 @@
 package envoy.server.data;
 
-import java.util.Date;
+import java.time.LocalDateTime;
+import java.util.HashMap;
 import java.util.Map;
 
 import javax.persistence.*;
@@ -16,14 +17,29 @@ import envoy.data.Group;
  * @since Envoy Server Standalone v0.1-beta
  */
 @Entity
+@NamedQuery(
+	name = GroupMessage.getPendingGroupMsg,
+	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.READ) AND (m.readDate > :lastSeen))"
+			+ "OR ((m.lastStatusChangeDate > :lastSeen)))"
+)
 public class GroupMessage extends Message {
 
+	/**
+	 * Named query retrieving pending group messages sent to a group containing a
+	 * specific user (parameter {@code userId}) that were sent after a certain time
+	 * stamp (parameter {@code :lastSeen}).
+	 * 
+	 * @since Envoy Server Standalone v0.1-beta
+	 */
+	public static final String getPendingGroupMsg = "GroupMessage.getPendingGroupMsg";
+
 	@ElementCollection
 	private Map<Long, envoy.data.Message.MessageStatus> memberMessageStatus;
 
 	@Column(name = "last_status_change_date")
-	@Temporal(TemporalType.TIMESTAMP)
+	protected LocalDateTime lastStatusChangeDate;
-	protected Date lastStatusChangeDate;
 
 	/**
 	 * The constructor for a database object.
@@ -38,12 +54,12 @@ public class GroupMessage extends Message {
 	 * @param groupMessage         the {@link envoy.data.GroupMessage} to convert
 	 *                             into a
 	 *                             database {@link GroupMessage}
-	 * @param lastStatusChangeDate the {@link Date} to set
+	 * @param lastStatusChangeDate the time stamp to set
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
-	public GroupMessage(envoy.data.GroupMessage groupMessage, Date lastStatusChangeDate) {
+	public GroupMessage(envoy.data.GroupMessage groupMessage, LocalDateTime lastStatusChangeDate) {
 		super(groupMessage);
-		memberMessageStatus	= groupMessage.getMemberStatuses();
+		memberMessageStatus			= groupMessage.getMemberStatuses();
 		this.lastStatusChangeDate	= lastStatusChangeDate;
 	}
 
@@ -57,7 +73,7 @@ public class GroupMessage extends Message {
 	 */
 	@Override
 	public envoy.data.GroupMessage toCommon() {
-		return prepareBuilder().buildGroupMessage((Group) recipient.toCommon(), memberMessageStatus);
+		return prepareBuilder().buildGroupMessage((Group) recipient.toCommon(), new HashMap<>(memberMessageStatus));
 	}
 
 	/**
@@ -78,11 +94,11 @@ public class GroupMessage extends Message {
 	 * @return the date at which one of the member statuses changed last
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
-	public Date getLastStatusChangeDate() { return lastStatusChangeDate; }
+	public LocalDateTime getLastStatusChangeDate() { return lastStatusChangeDate; }
 
 	/**
 	 * @param date the date to set
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
-	public void setLastStatusChangeDate(Date date) { lastStatusChangeDate = date; }
+	public void setLastStatusChangeDate(LocalDateTime date) { lastStatusChangeDate = date; }
 }

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

@@ -194,6 +194,22 @@ public class PersistenceManager {
 			.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
+	 * @return all groupMessages that the client does not yet have (unread
+	 *         groupMessages)
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	public List<GroupMessage> getPendingGroupMessages(User user) {
+		return entityManager.createNamedQuery(GroupMessage.getPendingGroupMsg)
+			.setParameter("userId", user.getID())
+			.setParameter("lastSeen", user.getLastSeen())
+			.getResultList();
+	}
+
 	/**
 	 * Searches for users matching a search phrase. Contacts of the attached user
 	 * and the attached user is ignored.

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

@@ -50,7 +50,7 @@ public class ConnectionManager implements ISocketIdListener {
 	public void socketCancelled(long socketID) {
 		if (!pendingSockets.remove(socketID)) {
 			// Notify contacts of this users offline-going
-			envoy.server.data.User user = PersistenceManager.getInstance().getUserByID(getUserIdBySocketID(socketID));
+			envoy.server.data.User user = PersistenceManager.getInstance().getUserByID(getUserIDBySocketID(socketID));
 			user.setStatus(UserStatus.OFFLINE);
 			user.setLastSeen(LocalDateTime.now());
 			UserStatusChangeProcessor.updateUserStatus(user);
@@ -87,7 +87,7 @@ public class ConnectionManager implements ISocketIdListener {
 	 * @return the userId associated with this socketId
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public long getUserIdBySocketID(long socketID) {
+	public long getUserIDBySocketID(long socketID) {
 		return sockets.entrySet().stream().filter(entry -> entry.getValue().equals(socketID)).findFirst().get().getKey();
 	}
 

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

@@ -4,6 +4,7 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.util.Set;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.jenkov.nioserver.IMessageProcessor;
@@ -50,11 +51,11 @@ public class ObjectMessageProcessor implements IMessageProcessor {
 			logger.fine("Received " + obj);
 
 			// Process object
-			processors.stream().filter(p -> p.getInputClass().isInstance(obj)).forEach((@SuppressWarnings("rawtypes") ObjectProcessor p) -> {
+			processors.stream().filter(p -> p.getInputClass().equals(obj.getClass())).forEach((@SuppressWarnings("rawtypes") ObjectProcessor p) -> {
 				try {
 					p.process(p.getInputClass().cast(obj), message.socketId, new ObjectWriteProxy(writeProxy));
 				} catch (IOException e) {
-					e.printStackTrace();
+					logger.log(Level.SEVERE, "Exception during processor execution: ", e);
 				}
 			});
 		} catch (IOException | ClassNotFoundException e) {

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

@@ -1,11 +1,14 @@
 package envoy.server.net;
 
 import java.io.IOException;
+import java.util.Set;
 import java.util.logging.Logger;
+import java.util.stream.Stream;
 
 import com.jenkov.nioserver.Message;
 import com.jenkov.nioserver.WriteProxy;
 
+import envoy.server.data.Contact;
 import envoy.util.EnvoyLog;
 import envoy.util.SerializationUtils;
 
@@ -23,7 +26,8 @@ public class ObjectWriteProxy {
 
 	private final WriteProxy writeProxy;
 
-	private static final Logger logger = EnvoyLog.getLogger(ObjectWriteProxy.class);
+	private static final ConnectionManager	connectionManager	= ConnectionManager.getInstance();
+	private static final Logger				logger				= EnvoyLog.getLogger(ObjectWriteProxy.class);
 
 	/**
 	 * Creates an instance of {@link ObjectWriteProxy}.
@@ -36,23 +40,49 @@ public class ObjectWriteProxy {
 	/**
 	 * @param recipientSocketID the socket id of the recipient
 	 * @param obj               the object to return to the client
-	 * @throws IOException if the serialization of the object failed
+	 * @throws RuntimeException if the serialization of the object failed (this is
+	 *                          highly unlikely)
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public void write(long recipientSocketID, Object obj) throws IOException {
+	public void write(long recipientSocketID, Object obj) {
 		// Create message targeted at the client
 		final Message response = writeProxy.getMessage();
 		response.socketId = recipientSocketID;
 		logger.fine("Sending " + obj);
 
-		// Serialize object to byte array
+		try {
-		final byte[] objBytes = SerializationUtils.writeToByteArray(obj);
 
-		// Acquire object length in bytes
+			// Serialize object to byte array
-		final byte[] objLen = SerializationUtils.intToBytes(objBytes.length);
+			final byte[] objBytes = SerializationUtils.writeToByteArray(obj);
 
-		response.writeToMessage(objLen);
+			// Acquire object length in bytes
-		response.writeToMessage(objBytes);
+			final byte[] objLen = SerializationUtils.intToBytes(objBytes.length);
-		writeProxy.enqueue(response);
+
+			response.writeToMessage(objLen);
+			response.writeToMessage(objBytes);
+			writeProxy.enqueue(response);
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	/**
+	 * Sends an object to all contact in a set that are online.
+	 * 
+	 * @param contacts the contacts to send the object to
+	 * @param message  the object to send
+	 * @since Envoy Server Standalone v0.1-beta
+	 */
+	public void writeToOnlineContacts(Set<? extends Contact> contacts, Object message) { writeToOnlineContacts(contacts.stream(), message); }
+
+	/**
+	 * Sends an object to all contact in a set that are online.
+	 * 
+	 * @param contacts the contacts to send the object to
+	 * @param message  the object to send
+	 * @since Envoy Server Standalone v0.1-beta
+	 */
+	public void writeToOnlineContacts(Stream<? extends Contact> contacts, Object message) {
+		contacts.map(Contact::getID).filter(connectionManager::isOnline).map(connectionManager::getSocketID).forEach(id -> write(id, message));
 	}
 }

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

@@ -1,6 +1,5 @@
 package envoy.server.processors;
 
-import java.io.IOException;
 import java.util.logging.Logger;
 
 import envoy.event.ElementOperation;
@@ -24,10 +23,10 @@ public class ContactOperationProcessor implements ObjectProcessor<ContactOperati
 	private static final Logger				logger				= EnvoyLog.getLogger(ContactOperationProcessor.class);
 
 	@Override
-	public void process(ContactOperation evt, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(ContactOperation evt, long socketId, ObjectWriteProxy writeProxy) {
 		switch (evt.getOperationType()) {
 			case ADD:
-				final long userID = ConnectionManager.getInstance().getUserIdBySocketID(socketId);
+				final long userID = ConnectionManager.getInstance().getUserIDBySocketID(socketId);
 				final long contactId = evt.get().getID();
 
 				logger.fine(String.format("Adding user %s to the contact list of user %d.%n", evt.get(), userID));
@@ -39,7 +38,7 @@ public class ContactOperationProcessor implements ObjectProcessor<ContactOperati
 							new ContactOperation(PersistenceManager.getInstance().getUserByID(userID).toCommon(), ElementOperation.ADD));
 				break;
 			default:
-				logger.warning(String.format("Received %s with an unsupported operation.%n", evt));
+				logger.warning(String.format("Received %s with an unsupported operation.", evt));
 		}
 	}
 

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

@@ -33,7 +33,7 @@ public class ContactSearchProcessor implements ObjectProcessor<ContactSearchRequ
 	public void process(ContactSearchRequest request, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		writeProxy.write(socketID,
 				new ContactSearchResult(PersistenceManager.getInstance()
-					.searchUsers(request.get(), ConnectionManager.getInstance().getUserIdBySocketID(socketID))
+					.searchUsers(request.get(), ConnectionManager.getInstance().getUserIDBySocketID(socketID))
 					.stream()
 					.map(User::toCommon)
 					.collect(Collectors.toList())));

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

@@ -1,6 +1,5 @@
 package envoy.server.processors;
 
-import java.io.IOException;
 import java.util.HashSet;
 
 import envoy.event.ElementOperation;
@@ -25,27 +24,21 @@ public class GroupCreationProcessor implements ObjectProcessor<GroupCreation> {
 	private final ConnectionManager		connectionManager	= ConnectionManager.getInstance();
 
 	@Override
-	public void process(GroupCreation groupCreation, long socketID, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(GroupCreation groupCreation, long socketID, ObjectWriteProxy writeProxy) {
 		envoy.server.data.Group group = new envoy.server.data.Group();
 		group.setName(groupCreation.get());
 		group.setContacts(new HashSet<>());
 		groupCreation.getInitialMemberIDs().stream().map(persistenceManager::getUserByID).forEach(group.getContacts()::add);
-		group.getContacts().add(persistenceManager.getContactByID(connectionManager.getUserIdBySocketID(socketID)));
+		group.getContacts().add(persistenceManager.getContactByID(connectionManager.getUserIDBySocketID(socketID)));
 		group.getContacts().forEach(c -> c.getContacts().add(group));
-		group.getContacts().add(persistenceManager.getUserByID(connectionManager.getUserIdBySocketID(socketID)));
+		group.getContacts().add(persistenceManager.getUserByID(connectionManager.getUserIDBySocketID(socketID)));
 		persistenceManager.addContact(group);
 		group.getContacts()
 			.stream()
 			.map(Contact::getID)
 			.filter(connectionManager::isOnline)
 			.map(connectionManager::getSocketID)
-			.forEach(memberSocketID -> {
+			.forEach(memberSocketID -> writeProxy.write(memberSocketID, new ContactOperation(group.toCommon(), ElementOperation.ADD)));
-				try {
-						writeProxy.write(memberSocketID, new ContactOperation(group.toCommon(), ElementOperation.ADD));
-				} catch (IOException e) {
-					e.printStackTrace();
-				}
-			});
 	}
 
 	@Override

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

@@ -1,13 +1,15 @@
 package envoy.server.processors;
 
-import java.io.IOException;
+import static envoy.data.Message.MessageStatus.*;
-import java.util.Date;
+
+import java.time.LocalDateTime;
+import java.util.Collections;
 import java.util.logging.Logger;
 
 import javax.persistence.EntityExistsException;
 
 import envoy.data.GroupMessage;
-import envoy.data.Message.MessageStatus;
+import envoy.event.MessageStatusChange;
 import envoy.server.data.PersistenceManager;
 import envoy.server.net.ConnectionManager;
 import envoy.server.net.ObjectWriteProxy;
@@ -23,45 +25,43 @@ import envoy.util.EnvoyLog;
  */
 public class GroupMessageProcessor implements ObjectProcessor<GroupMessage> {
 
-	private static final Logger logger = EnvoyLog.getLogger(GroupCreationProcessor.class);
+	private static final ConnectionManager	connectionManager	= ConnectionManager.getInstance();
+	private static final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
+	private static final Logger				logger				= EnvoyLog.getLogger(GroupCreationProcessor.class);
 
 	@Override
 	public void process(GroupMessage groupMessage, long socketID, ObjectWriteProxy writeProxy) {
 		groupMessage.nextStatus();
-		ConnectionManager connectionManager = ConnectionManager.getInstance();
 
-		final var members = PersistenceManager.getInstance().getGroupByID(groupMessage.getRecipientID()).getContacts();
+		// Update statuses to SENT / RECEIVED depending on online status
-		groupMessage.getMemberStatuses().replaceAll((id, oldStatus) -> MessageStatus.SENT);
+		groupMessage.getMemberStatuses().replaceAll((memberID, status) -> connectionManager.isOnline(memberID) ? RECEIVED : SENT);
-		members.forEach(user -> setMemberStatus(connectionManager, groupMessage, user.getID()));
 
-		// Checks if all memberMessageStatuses are RECEIVED and if so sets the
+		// Set status for sender to READ
-		// groupMessage Status to RECEIVED.
+		groupMessage.getMemberStatuses().replace(groupMessage.getSenderID(), READ);
 
-		members.forEach(user -> { sendToMember(connectionManager, groupMessage, user.getID(), writeProxy); });
+		// Increment the overall status to RECEIVED if necessary
+		if (Collections.min(groupMessage.getMemberStatuses().values()) == RECEIVED) {
+			groupMessage.nextStatus();
+
+			// Notify the sender of the status change
+			writeProxy.write(socketID, new MessageStatusChange(groupMessage));
+		}
+
+		// Deliver the message to the recipients that are online
+		writeProxy.writeToOnlineContacts(
+				persistenceManager.getGroupByID(groupMessage.getRecipientID())
+					.getContacts()
+					.stream()
+					.filter(c -> c.getID() != groupMessage.getSenderID()),
+				groupMessage);
 
 		try {
-			PersistenceManager.getInstance().addMessage(new envoy.server.data.GroupMessage(groupMessage, new Date()));
+			PersistenceManager.getInstance().addMessage(new envoy.server.data.GroupMessage(groupMessage, LocalDateTime.now()));
 		} catch (EntityExistsException e) {
 			logger.warning("Received a groupMessage with an ID that already exists");
 		}
 	}
 
-	private void sendToMember(ConnectionManager connectionManager, GroupMessage groupMessage, long memberID, ObjectWriteProxy writeProxy) {
-		if (connectionManager.isOnline(memberID)) try {
-			// If recipient is online, send the groupMessage directly
-			writeProxy.write(connectionManager.getSocketID(memberID), groupMessage);
-		} catch (IOException e) {
-			logger.warning("Recipient online. Failed to send message" + groupMessage.getID());
-			e.printStackTrace();
-		}
-	}
-
-	private void setMemberStatus(ConnectionManager connectionManager, GroupMessage groupMessage, long memberID) {
-		if (connectionManager.isOnline(memberID))
-			// Update the message status of the member to RECEIVED
-			groupMessage.getMemberStatuses().replace(memberID, MessageStatus.RECEIVED);
-	}
-
 	@Override
 	public Class<GroupMessage> getInputClass() { return GroupMessage.class; }
 }

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

@@ -0,0 +1,69 @@
+package envoy.server.processors;
+
+import static envoy.data.Message.MessageStatus.READ;
+
+import java.time.LocalDateTime;
+import java.util.Collections;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import envoy.data.Message.MessageStatus;
+import envoy.event.GroupMessageStatusChange;
+import envoy.event.MessageStatusChange;
+import envoy.server.data.GroupMessage;
+import envoy.server.data.PersistenceManager;
+import envoy.server.net.ConnectionManager;
+import envoy.server.net.ObjectWriteProxy;
+import envoy.util.EnvoyLog;
+
+/**
+ * Project: <strong>envoy-server-standalone</strong><br>
+ * File: <strong>GroupMessageStatusChangeProcessor.java</strong><br>
+ * Created: <strong>03.07.2020</strong><br>
+ * 
+ * @author Maximilian K&auml;fer
+ * @since Envoy Server Standalone v0.1-beta
+ */
+public class GroupMessageStatusChangeProcessor implements ObjectProcessor<GroupMessageStatusChange> {
+
+	private static final ConnectionManager	connectionManager	= ConnectionManager.getInstance();
+	private static final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
+	private static final Logger				logger				= EnvoyLog.getLogger(MessageStatusChangeProcessor.class);
+
+	@Override
+	public void process(GroupMessageStatusChange statusChange, long socketID, ObjectWriteProxy writeProxy) {
+		GroupMessage gmsg = (GroupMessage) persistenceManager.getMessageByID(statusChange.getID());
+
+		// Any other status than READ is not supposed to be sent to the server
+		if (statusChange.get() != MessageStatus.READ) {
+			logger.log(Level.WARNING, "Invalid " + statusChange);
+			return;
+		}
+
+		// Apply the status change
+		gmsg.getMemberMessageStatus().replace(statusChange.getMemberID(), statusChange.get());
+		gmsg.setLastStatusChangeDate(LocalDateTime.now());
+
+		// Notifying the other members about the status change
+		final var userID = connectionManager.getUserIDBySocketID(socketID);
+		gmsg.getMemberMessageStatus()
+			.keySet()
+			.stream()
+			.filter(k -> userID != k)
+			.filter(connectionManager::isOnline)
+			.forEach(k -> writeProxy.write(connectionManager.getSocketID(k), statusChange));
+
+		// Increment overall status to READ if necessary
+		if (Collections.min(gmsg.getMemberMessageStatus().values()) == READ) {
+			gmsg.read();
+
+			// Notify online members about the status change
+			writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
+					new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), LocalDateTime.now()));
+		}
+		persistenceManager.updateMessage(gmsg);
+	}
+
+	@Override
+	public Class<GroupMessageStatusChange> getInputClass() { return GroupMessageStatusChange.class; }
+}

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

@@ -1,7 +1,5 @@
 package envoy.server.processors;
 
-import java.io.IOException;
-
 import envoy.event.GroupResize;
 import envoy.server.data.Contact;
 import envoy.server.data.PersistenceManager;
@@ -22,7 +20,7 @@ public class GroupResizeProcessor implements ObjectProcessor<GroupResize> {
 	private static final ConnectionManager	connectionManager	= ConnectionManager.getInstance();
 
 	@Override
-	public void process(GroupResize groupResize, long socketID, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(GroupResize groupResize, long socketID, ObjectWriteProxy writeProxy) {
 
 		// Acquire the group to resize from the database
 		var group = persistenceManager.getGroupByID(groupResize.getGroupID());
@@ -47,13 +45,7 @@ public class GroupResizeProcessor implements ObjectProcessor<GroupResize> {
 			.map(Contact::getID)
 			.filter(connectionManager::isOnline)
 			.map(connectionManager::getSocketID)
-			.forEach(memberSocketID -> {
+			.forEach(memberSocketID -> writeProxy.write(memberSocketID, commonGroup));
-				try {
-					writeProxy.write(memberSocketID, commonGroup);
-				} catch (IOException e) {
-					e.printStackTrace();
-				}
-			});
 	}
 
 	@Override

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

@@ -1,20 +1,20 @@
 package envoy.server.processors;
 
+import static envoy.data.Message.MessageStatus.*;
 import static envoy.data.User.UserStatus.ONLINE;
 import static envoy.event.HandshakeRejection.*;
 
-import java.io.IOException;
 import java.time.LocalDateTime;
-import java.util.Arrays;
+import java.util.*;
-import java.util.HashSet;
 import java.util.logging.Logger;
 
 import javax.persistence.NoResultException;
 
 import envoy.data.LoginCredentials;
-import envoy.data.Message.MessageStatus;
+import envoy.event.GroupMessageStatusChange;
 import envoy.event.HandshakeRejection;
 import envoy.event.MessageStatusChange;
+import envoy.server.data.GroupMessage;
 import envoy.server.data.PersistenceManager;
 import envoy.server.data.User;
 import envoy.server.net.ConnectionManager;
@@ -42,7 +42,7 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 	private static final Logger logger = EnvoyLog.getLogger(LoginCredentialProcessor.class);
 
 	@Override
-	public void process(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) {
 
 		// Cache this write proxy for user-independant notifications
 		UserStatusChangeProcessor.setWriteProxy(writeProxy);
@@ -83,25 +83,25 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 				writeProxy.write(socketID, new HandshakeRejection(INTERNAL_ERROR));
 				return;
 			}
-				try {
+			try {
-					// Checking that no user already has this identifier
+				// Checking that no user already has this identifier
-					PersistenceManager.getInstance().getUserByName(credentials.getIdentifier());
+				PersistenceManager.getInstance().getUserByName(credentials.getIdentifier());
 
-					// This code only gets executed if this user already exists
+				// This code only gets executed if this user already exists
-					logger.info("The requested user already exists.");
+				logger.info("The requested user already exists.");
-					writeProxy.write(socketID, new HandshakeRejection(USERNAME_TAKEN));
+				writeProxy.write(socketID, new HandshakeRejection(USERNAME_TAKEN));
-					return;
+				return;
-				} catch (NoResultException e) {
+			} catch (NoResultException e) {
-					// Creation of a new user
+				// Creation of a new user
-					user = new User();
+				user = new User();
-					user.setName(credentials.getIdentifier());
+				user.setName(credentials.getIdentifier());
-					user.setLastSeen(LocalDateTime.now());
+				user.setLastSeen(LocalDateTime.now());
-					user.setStatus(ONLINE);
+				user.setStatus(ONLINE);
-					user.setPasswordHash(credentials.getPasswordHash());
+				user.setPasswordHash(credentials.getPasswordHash());
-					user.setContacts(new HashSet<>());
+				user.setContacts(new HashSet<>());
-					persistenceManager.addContact(user);
+				persistenceManager.addContact(user);
-					logger.info("Registered new " + user);
+				logger.info("Registered new " + user);
-				}
+			}
 		}
 
 		logger.info(user + " successfully authenticated.");
@@ -115,11 +115,12 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 		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() == MessageStatus.SENT) {
+			if (msg.getStatus() == SENT) {
 
 				// Send the message
 				writeProxy.write(socketID, msgCommon);
@@ -133,6 +134,51 @@ public final class LoginCredentialProcessor implements ObjectProcessor<LoginCred
 				}
 			} else writeProxy.write(socketID, new MessageStatusChange(msgCommon));
 		}
+
+		List<GroupMessage> pendingGroupMessages = PersistenceManager.getInstance().getPendingGroupMessages(user);
+		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) {
+				gmsg.getMemberMessageStatus().replace(user.getID(), RECEIVED);
+
+				gmsg.setLastStatusChangeDate(LocalDateTime.now());
+
+				writeProxy.write(socketID, gmsgCommon);
+
+				// 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()));
+				}
+
+				PersistenceManager.getInstance().updateMessage(gmsg);
+			} 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) -> 
+					writeProxy.write(socketID, new GroupMessageStatusChange(gmsg.getID(), memberStatus, gmsg.getLastStatusChangeDate(), memberID)));
+				}
+
+				// Deliver just a status change instead of the whole message
+				if (gmsg.getStatus() == SENT && user.getLastSeen().isBefore(gmsg.getCreationDate())
+						|| gmsg.getStatus() == RECEIVED && user.getLastSeen().isBefore(gmsg.getReceivedDate()))
+					writeProxy.write(socketID, new MessageStatusChange(gmsgCommon));
+			}
+		}
 	}
 
 	@Override

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

@@ -1,13 +1,11 @@
 package envoy.server.processors;
 
-import java.io.IOException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.persistence.EntityExistsException;
 
 import envoy.data.Message;
-import envoy.data.Message.MessageStatus;
 import envoy.event.MessageStatusChange;
 import envoy.server.data.PersistenceManager;
 import envoy.server.net.ConnectionManager;
@@ -29,14 +27,10 @@ public class MessageProcessor implements ObjectProcessor<Message> {
 
 	private static final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
 	private static final ConnectionManager	connectionManager	= ConnectionManager.getInstance();
-	private static final Logger logger = EnvoyLog.getLogger(MessageProcessor.class);
+	private static final Logger				logger				= EnvoyLog.getLogger(MessageProcessor.class);
 
 	@Override
 	public void process(Message message, long socketID, ObjectWriteProxy writeProxy) {
-		if (message.getStatus() != MessageStatus.WAITING) {
-			logger.warning("Received message with invalid status: " + message);
-			return;
-		}
 		message.nextStatus();
 
 		// Convert to server message
@@ -62,8 +56,6 @@ public class MessageProcessor implements ObjectProcessor<Message> {
 			}
 		} catch (EntityExistsException e) {
 			logger.log(Level.WARNING, "Received " + message + " with an ID that already exists!");
-		} catch (IOException e) {
-			logger.log(Level.WARNING, "Failed to deliver " + message + ":", e);
 		}
 	}
 

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

@@ -1,13 +1,15 @@
 package envoy.server.processors;
 
 import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import envoy.data.Message.MessageStatus;
 import envoy.event.MessageStatusChange;
-import envoy.exception.EnvoyException;
 import envoy.server.data.PersistenceManager;
 import envoy.server.net.ConnectionManager;
 import envoy.server.net.ObjectWriteProxy;
+import envoy.util.EnvoyLog;
 
 /**
  * Project: <strong>envoy-server-standalone</strong><br>
@@ -19,13 +21,18 @@ import envoy.server.net.ObjectWriteProxy;
  */
 public class MessageStatusChangeProcessor implements ObjectProcessor<MessageStatusChange> {
 
-	private final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
 	private final ConnectionManager		connectionManager	= ConnectionManager.getInstance();
+	private final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
+	private final Logger				logger				= EnvoyLog.getLogger(MessageStatusChangeProcessor.class);
 
 	@Override
 	public void process(MessageStatusChange statusChange, long socketID, ObjectWriteProxy writeProxy) throws IOException {
+
 		// Any other status than READ is not supposed to be sent to the server
-		if (statusChange.get() != MessageStatus.READ) throw new IOException(new EnvoyException(statusChange + " has an invalid status"));
+		if (statusChange.get() != MessageStatus.READ) {
+			logger.log(Level.WARNING, "Invalid " + statusChange);
+			return;
+		}
 
 		final var msg = persistenceManager.getMessageByID(statusChange.getID());
 		msg.read();

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

@@ -5,8 +5,6 @@ import java.io.IOException;
 import envoy.event.NameChange;
 import envoy.server.data.Contact;
 import envoy.server.data.PersistenceManager;
-import envoy.server.data.User;
-import envoy.server.net.ConnectionManager;
 import envoy.server.net.ObjectWriteProxy;
 
 /**
@@ -19,22 +17,16 @@ import envoy.server.net.ObjectWriteProxy;
  */
 public class NameChangeProcessor implements ObjectProcessor<NameChange> {
 
+	private static final PersistenceManager persistenceManager = PersistenceManager.getInstance();
+
 	@Override
 	public void process(NameChange nameChange, long socketID, ObjectWriteProxy writeProxy) throws IOException {
-		PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
+		Contact toUpdate = persistenceManager.getContactByID(nameChange.getID());
-		ConnectionManager	connectionManager	= ConnectionManager.getInstance();
-		Contact				toUpdate			= persistenceManager.getContactByID(nameChange.getID());
 		toUpdate.setName(nameChange.get());
 		persistenceManager.updateContact(toUpdate);
 
 		// Notify online contacts of the name change
-		toUpdate.getContacts().stream().filter(User.class::isInstance).map(Contact::getID).filter(connectionManager::isOnline).forEach(userID -> {
+		writeProxy.writeToOnlineContacts(toUpdate.getContacts(), nameChange);
-			try {
-				writeProxy.write(userID, nameChange);
-			} catch (IOException e) {
-				e.printStackTrace();
-			}
-		});
 	}
 
 	@Override

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

@@ -1,19 +1,17 @@
 package envoy.server.processors;
 
-import java.io.IOException;
 import java.util.logging.Logger;
 
 import envoy.data.User.UserStatus;
 import envoy.event.UserStatusChange;
 import envoy.server.data.PersistenceManager;
 import envoy.server.data.User;
-import envoy.server.net.ConnectionManager;
 import envoy.server.net.ObjectWriteProxy;
 import envoy.util.EnvoyLog;
 
 /**
- * This processor handles incoming {@link UserStatusChange}.<br>
+ * This processor handles incoming {@link UserStatusChange}.
- * <br>
+ * <p>
  * Project: <strong>envoy-server-standalone</strong><br>
  * File: <strong>UserStatusChangeProcessor.java</strong><br>
  * Created: <strong>1 Feb 2020</strong><br>
@@ -23,16 +21,16 @@ import envoy.util.EnvoyLog;
  */
 public class UserStatusChangeProcessor implements ObjectProcessor<UserStatusChange> {
 
-	private static ObjectWriteProxy		writeProxy;
+	private static ObjectWriteProxy writeProxy;
-	private static PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
 
-	private static final Logger logger = EnvoyLog.getLogger(UserStatusChangeProcessor.class);
+	private static final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
+	private static final Logger				logger				= EnvoyLog.getLogger(UserStatusChangeProcessor.class);
 
 	@Override
 	public Class<UserStatusChange> getInputClass() { return UserStatusChange.class; }
 
 	@Override
-	public void process(UserStatusChange input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(UserStatusChange input, long socketID, ObjectWriteProxy writeProxy) {
 		// new status should not equal old status
 		if (input.get().equals(persistenceManager.getUserByID(input.getID()).getStatus())) {
 			logger.warning("Received an unnecessary UserStatusChange");
@@ -55,7 +53,7 @@ public class UserStatusChangeProcessor implements ObjectProcessor<UserStatusChan
 		persistenceManager.updateContact(user);
 
 		// Handling for contacts that are already online
-		notifyContacts(user);
+		writeProxy.writeToOnlineContacts(user.getContacts(), new UserStatusChange(user.getID(), user.getStatus()));
 	}
 
 	/**
@@ -64,25 +62,6 @@ public class UserStatusChangeProcessor implements ObjectProcessor<UserStatusChan
 	 */
 	public static void updateUserStatus(UserStatusChange evt) { updateUserStatus(persistenceManager.getUserByID(evt.getID())); }
 
-	/**
-	 * notifies active contacts of this {@link User} that his {@link UserStatus} has
-	 * changed
-	 *
-	 * @param user the {@link User}
-	 * @since Envoy Server Standalone v0.1-alpha
-	 */
-	private static void notifyContacts(User user) {
-		UserStatusChange	evt					= new UserStatusChange(user.getID(), user.getStatus());
-		ConnectionManager		connectionManager	= ConnectionManager.getInstance();
-		try {
-			for (envoy.server.data.Contact contact : user.getContacts())
-				if (connectionManager.isOnline(contact.getID())) writeProxy.write(connectionManager.getSocketID(contact.getID()), evt);
-		} catch (IOException e) {
-			e.printStackTrace();
-			logger.warning("Could not notify online contacts of user " + evt.getID() + " that his status has been changed");
-		}
-	}
-
 	/**
 	 * This method is only called by the LoginCredentialProcessor because every
 	 * user needs to login (open a socket) before changing his status.