Created method to extract all currently online members of a group

additionally, refactored every ".Id" to ".ID"

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

@@ -1,15 +1,14 @@
 package envoy.server.net;
 
-import java.util.Date;
+import java.util.*;
-import java.util.HashMap;
+import java.util.stream.Collectors;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
 
 import com.jenkov.nioserver.ISocketIdListener;
 
 import envoy.data.User.UserStatus;
+import envoy.server.data.Group;
 import envoy.server.data.PersistenceManager;
+import envoy.server.data.User;
 import envoy.server.processors.UserStatusChangeProcessor;
 
 /**
@@ -48,60 +47,74 @@ public class ConnectionManager implements ISocketIdListener {
 	public static ConnectionManager getInstance() { return connectionManager; }
 
 	@Override
-	public void socketCancelled(long socketId) {
+	public void socketCancelled(long socketID) {
-		if (!pendingSockets.remove(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(new Date());
 			UserStatusChangeProcessor.updateUserStatus(user);
 
 			// Remove the socket
-			sockets.entrySet().removeIf(e -> e.getValue() == socketId);
+			sockets.entrySet().removeIf(e -> e.getValue() == socketID);
 		}
 	}
 
 	@Override
-	public void socketRegistered(long socketId) { pendingSockets.add(socketId); }
+	public void socketRegistered(long socketID) { pendingSockets.add(socketID); }
 
 	/**
 	 * Associates a socket ID with a user ID.
 	 *
-	 * @param userId   the user ID
+	 * @param userID   the user ID
-	 * @param socketId the socket ID
+	 * @param socketID the socket ID
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public void registerUser(long userId, long socketId) {
+	public void registerUser(long userID, long socketID) {
-		sockets.put(userId, socketId);
+		sockets.put(userID, socketID);
-		pendingSockets.remove(socketId);
+		pendingSockets.remove(socketID);
 	}
 
 	/**
-	 * @param userId the ID of the user registered at a socket
+	 * @param userID the ID of the user registered at a socket
 	 * @return the ID of the socket
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public long getSocketId(long userId) { return sockets.get(userId); }
+	public long getSocketId(long userID) { return sockets.get(userID); }
 
 	/**
-	 * @param socketId the id of the socket whose User is needed
+	 * @param socketID the id of the socket whose User is needed
 	 * @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();
+		return sockets.entrySet().stream().filter(entry -> entry.getValue().equals(socketID)).findFirst().get().getKey();
 	}
 
 	/**
-	 * @param userId the ID of the user to check for
+	 * @param userID the ID of the user to check for
 	 * @return {@code true} if the user is online
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public boolean isOnline(long userId) { return sockets.containsKey(userId); }
+	public boolean isOnline(long userID) { return sockets.containsKey(userID); }
 
 	/**
-	 * @return the userId of all users who are currently online
+	 * @return the userIDs of all users who are currently online
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
 	public Set<Long> getOnlineUsers() { return sockets.keySet(); }
+
+	/**
+	 * Returns all members of a group who are currently online.
+	 *
+	 * @param group the group to search for
+	 * @return a set of all IDs of currently active members in this group
+	 * @since Envoy Server Standalone v0.1-beta
+	 */
+	public Set<Long> getOnlineUsersOfGroup(Group group) {
+		Set<Long>	onlineMembers	= new HashSet<>();
+		Set<Long>	members			= group.getMembers().stream().map(User::getID).collect(Collectors.toSet());
+		members.forEach(userID -> { if (isOnline(userID)) onlineMembers.add(userID); });
+		return onlineMembers;
+	}
 }

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

@@ -30,15 +30,15 @@ public class ObjectWriteProxy {
 	public ObjectWriteProxy(WriteProxy writeProxy) { this.writeProxy = writeProxy; }
 
 	/**
-	 * @param recipientSocketId the socket id of the recipient
+	 * @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
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public void write(long recipientSocketId, Object obj) throws IOException {
+	public void write(long recipientSocketID, Object obj) throws IOException {
 		// Create message targeted at the client
 		Message response = writeProxy.getMessage();
-		response.socketId = recipientSocketId;
+		response.socketId = recipientSocketID;
 
 		// Serialize object to byte array
 		byte[] objBytes = SerializationUtils.writeToByteArray(obj);

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

@@ -25,15 +25,15 @@ public class ContactOperationProcessor implements ObjectProcessor<ContactOperati
 	public void process(ContactOperationEvent evt, long socketId, ObjectWriteProxy writeProxy) throws IOException {
 		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();
 
-				System.out.printf("Adding user %s to the contact list of user %d.%n", evt.get(), userId);
+				System.out.printf("Adding user %s to the contact list of user %d.%n", evt.get(), userID);
-				PersistenceManager.getInstance().addUserContact(userId, contactId);
+				PersistenceManager.getInstance().addUserContact(userID, contactId);
 
 				// Notify the contact if online
 				if (ConnectionManager.getInstance().isOnline(contactId)) writeProxy.write(connectionManager.getSocketId(contactId),
-						new Contacts(Arrays.asList(PersistenceManager.getInstance().getUserById(userId).toCommon())));
+						new Contacts(Arrays.asList(PersistenceManager.getInstance().getUserById(userID).toCommon())));
 				break;
 			default:
 				System.err.printf("Received %s with an unsupported operation.%n", evt);

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

@@ -30,10 +30,10 @@ public class ContactsRequestEventProcessor implements ObjectProcessor<ContactSea
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
 	@Override
-	public void process(ContactSearchRequest request, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(ContactSearchRequest request, long socketID, ObjectWriteProxy writeProxy) throws IOException {
-		writeProxy.write(socketId,
+		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

@@ -19,13 +19,13 @@ public class GroupCreationProcessor implements ObjectProcessor<GroupCreationEven
 	private final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
 
 	@Override
-	public void process(GroupCreationEvent input, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(GroupCreationEvent input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		envoy.server.data.Group group = new envoy.server.data.Group();
 		group.setName(input.get());
 		// TODO adjust event, so it sends a members list as well, which can be initially
 		// set here
 		persistenceManager.addContact(group);
-		writeProxy.write(socketId, group); // TODO Prepare the client to receive the group object after sending the
+		writeProxy.write(socketID, group); // TODO Prepare the client to receive the group object after sending the
 											// groupCreationEvent to the server.
 	}
 

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

@@ -25,11 +25,11 @@ public class IDGeneratorRequestProcessor implements ObjectProcessor<IDGeneratorR
 	public Class<IDGeneratorRequest> getInputClass() { return IDGeneratorRequest.class; }
 
 	@Override
-	public void process(IDGeneratorRequest input, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(IDGeneratorRequest input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		System.out.println("Received id generation request.");
 		var generator = createIDGenerator();
 		System.out.println("Sending new id generator " + generator);
-		writeProxy.write(socketId, generator);
+		writeProxy.write(socketID, generator);
 	}
 
 	/**
@@ -44,10 +44,10 @@ public class IDGeneratorRequestProcessor implements ObjectProcessor<IDGeneratorR
 	 * @since Envoy Server Standalone v0.1-beta
 	 */
 	public static IDGenerator createIDGenerator(long range) {
-		ConfigItem	currentId	= PersistenceManager.getInstance().getConfigItemById("currentMessageId");
+		ConfigItem	currentID	= PersistenceManager.getInstance().getConfigItemById("currentMessageId");
-		IDGenerator	generator	= new IDGenerator(Integer.parseInt(currentId.getValue()), range);
+		IDGenerator	generator	= new IDGenerator(Integer.parseInt(currentID.getValue()), range);
-		currentId.setValue(String.valueOf(Integer.parseInt(currentId.getValue()) + range));
+		currentID.setValue(String.valueOf(Integer.parseInt(currentID.getValue()) + range));
-		PersistenceManager.getInstance().updateConfigItem(currentId);
+		PersistenceManager.getInstance().updateConfigItem(currentID);
 		return generator;
 	}
 }

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

@@ -38,18 +38,18 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 	private final ConnectionManager		connectionManager	= ConnectionManager.getInstance();
 
 	@Override
-	public void process(LoginCredentials input, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(LoginCredentials input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		UserStatusChangeProcessor.setWriteProxy(writeProxy);
-		System.out.println(String.format("Received login credentials %s from socket ID %d", input, socketId));
+		System.out.println(String.format("Received login credentials %s from socket ID %d", input, socketID));
 
-		envoy.server.data.User user = getUser(input, socketId, writeProxy);
+		envoy.server.data.User user = getUser(input, socketID, writeProxy);
 
 		// Not logged in successfully
 		if (user == null) {
-			System.out.println("Rejecting handshake on socket " + socketId);
+			System.out.println("Rejecting handshake on socket " + socketID);
 			return;
 		}
-		connectionManager.registerUser(user.getID(), socketId);
+		connectionManager.registerUser(user.getID(), socketID);
 
 		// Notifies contacts of this users online-going and updates his status in the
 		// database
@@ -62,14 +62,14 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 
 		// Complete handshake
 		System.out.println("Sending user...");
-		writeProxy.write(socketId, user.toCommon());
+		writeProxy.write(socketID, user.toCommon());
 		System.out.println("Sending contacts...");
-		writeProxy.write(socketId, contacts);
+		writeProxy.write(socketID, contacts);
 		System.out.println("Acquiring pending messages for the client...");
 		List<Message> pendingMessages = PersistenceManager.getInstance().getUnreadMessages(user);
 		for (Message msg : pendingMessages) {
 			System.out.println("Sending message " + msg.toCommonMessage());
-			writeProxy.write(socketId, msg.toCommonMessage());
+			writeProxy.write(socketID, msg.toCommonMessage());
 			msg.setReceivedDate(new Date());
 			msg.setStatus(MessageStatus.RECEIVED);
 			PersistenceManager.getInstance().updateMessage(msg);
@@ -79,13 +79,13 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 	@Override
 	public Class<LoginCredentials> getInputClass() { return LoginCredentials.class; }
 
-	private envoy.server.data.User getUser(LoginCredentials credentials, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	private envoy.server.data.User getUser(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) throws IOException {
-		return credentials.isRegistration() ? newUser(credentials, socketId, writeProxy) : checkForExistingUser(credentials, socketId, writeProxy);
+		return credentials.isRegistration() ? newUser(credentials, socketID, writeProxy) : checkForExistingUser(credentials, socketID, writeProxy);
 	}
 
 	/**
 	 * @param credentials the input to evaluate
-	 * @param socketId    the socket ID at which the client performing the handshake
+	 * @param socketID    the socket ID at which the client performing the handshake
 	 *                    is connected
 	 * @param writeProxy  the {@link ObjectWriteProxy} to use if login was not
 	 *                    successful
@@ -93,34 +93,34 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 	 * @throws IOException if sending the failed login back to the client failed
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	private envoy.server.data.User checkForExistingUser(LoginCredentials credentials, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	private envoy.server.data.User checkForExistingUser(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		try {
 			envoy.server.data.User user = persistenceManager.getUserByName(credentials.getIdentifier());
 
 			// Checking if user is already online
 			if (connectionManager.isOnline(user.getID())) {
-				writeProxy.write(socketId, new HandshakeRejectionEvent(HandshakeRejectionEvent.ALREADY_ONLINE));
+				writeProxy.write(socketID, new HandshakeRejectionEvent(HandshakeRejectionEvent.ALREADY_ONLINE));
 				return null;
 			}
 			// Evaluating the correctness of the password hash
 			if (!Arrays.equals(credentials.getPasswordHash(), user.getPasswordHash())) {
-				writeProxy.write(socketId, new HandshakeRejectionEvent(HandshakeRejectionEvent.WRONG_PASSWORD));
+				writeProxy.write(socketID, new HandshakeRejectionEvent(HandshakeRejectionEvent.WRONG_PASSWORD));
 				return null;
 			}
 			return user;
 		} catch (NoResultException e) {
 			// Checking if user exists
-			writeProxy.write(socketId, new HandshakeRejectionEvent(HandshakeRejectionEvent.USER_DOES_NOT_EXIST));
+			writeProxy.write(socketID, new HandshakeRejectionEvent(HandshakeRejectionEvent.USER_DOES_NOT_EXIST));
 		} catch (InputMismatchException e) {
 			// Checking if the given password hash is correct
-			writeProxy.write(socketId, new HandshakeRejectionEvent(HandshakeRejectionEvent.WRONG_PASSWORD));
+			writeProxy.write(socketID, new HandshakeRejectionEvent(HandshakeRejectionEvent.WRONG_PASSWORD));
 		}
 		return null;
 	}
 
 	/**
 	 * @param credentials the credentials upon which to create the new {@link User}
-	 * @param socketId    the socketID at which the client performing the handshake
+	 * @param socketID    the socketID at which the client performing the handshake
 	 *                    is connected
 	 * @param writeProxy  the write proxy used to notify the client about handshake
 	 *                    rejection
@@ -128,12 +128,12 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 	 * @throws IOException if sending the failed login back to the client failed
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	private envoy.server.data.User newUser(LoginCredentials credentials, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	private envoy.server.data.User newUser(LoginCredentials credentials, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		try {
 			// Checking that no user already has this identifier
 			PersistenceManager.getInstance().getUserByName(credentials.getIdentifier());
 			// this code only gets executed if this user already exists
-			writeProxy.write(socketId, new HandshakeRejectionEvent(HandshakeRejectionEvent.USER_EXISTS_ALREADY));
+			writeProxy.write(socketID, new HandshakeRejectionEvent(HandshakeRejectionEvent.USER_EXISTS_ALREADY));
 			return null;
 		} catch (NoResultException e) {
 			// Creation of a new user

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

@@ -26,7 +26,7 @@ import envoy.server.net.ObjectWriteProxy;
 public class MessageProcessor implements ObjectProcessor<Message> {
 
 	@Override
-	public void process(Message message, long socketId, ObjectWriteProxy writeProxy) {
+	public void process(Message message, long socketID, ObjectWriteProxy writeProxy) {
 		message.nextStatus();
 		ConnectionManager	connectionManager	= ConnectionManager.getInstance();
 		Contact				recipient			= PersistenceManager.getInstance().getContactById(message.getID());
@@ -36,7 +36,7 @@ public class MessageProcessor implements ObjectProcessor<Message> {
 			sendToUser(connectionManager, message, writeProxy);
 			// Sending a messageStatusChangeEvent to the sender
 			try {
-				writeProxy.write(socketId, new MessageStatusChangeEvent(message));
+				writeProxy.write(socketID, new MessageStatusChangeEvent(message));
 			} catch (IOException e) {
 				System.err.println("Could not send messageStatusChangeEvent to the sender of this message with ID: " + message.getID());
 				e.printStackTrace();

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

@@ -23,7 +23,7 @@ public class MessageStatusChangeProcessor implements ObjectProcessor<MessageStat
 	private final ConnectionManager		connectionManager	= ConnectionManager.getInstance();
 
 	@Override
-	public void process(MessageStatusChangeEvent input, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(MessageStatusChangeEvent input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		// Any other status than READ is not supposed to be sent to the server
 		if (input.get() != MessageStatus.READ) throw new IOException(new EnvoyException("Message " + input + " has an invalid status"));
 

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

@@ -26,10 +26,10 @@ public interface ObjectProcessor<T> {
 
 	/**
 	 * @param input      the request object
-	 * @param socketId   the ID of the socket from which the object was received
+	 * @param socketID   the ID of the socket from which the object was received
 	 * @param writeProxy the object that allows writing to a client
 	 * @throws IOException if something went wrong during processing
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	void process(T input, long socketId, ObjectWriteProxy writeProxy) throws IOException;
+	void process(T input, long socketID, ObjectWriteProxy writeProxy) throws IOException;
 }

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

@@ -28,7 +28,7 @@ public class UserStatusChangeProcessor implements ObjectProcessor<UserStatusChan
 	public Class<UserStatusChangeEvent> getInputClass() { return UserStatusChangeEvent.class; }
 
 	@Override
-	public void process(UserStatusChangeEvent input, long socketId, ObjectWriteProxy writeProxy) throws IOException {
+	public void process(UserStatusChangeEvent input, long socketID, ObjectWriteProxy writeProxy) throws IOException {
 		// new status should not equal old status
 		if (input.get().equals(persistenceManager.getUserById(input.getID()).getStatus())) {
 			System.out.println("Received an unnecessary UserStatusChangeEvent");