Revised structure

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

@@ -31,51 +31,30 @@ import envoy.schema.User;
 public class Client {
 
 	private ObjectFactory	objectFactory	= new ObjectFactory();
-	private DatatypeFactory	datatypeFactory;
 	private Config			config;
 	private User			sender, recipient;
 
-	private Sync	unreadMessagesSync	= objectFactory.createSync();
-	public Sync		sync				= objectFactory.createSync();
-	public Sync		readMessages		= objectFactory.createSync();
-
 	public Client(Config config, String username) {
-		this.config = config;
+		this.config	= config;
-		try {
+		sender		= getUser(username);
-			datatypeFactory = DatatypeFactory.newInstance();
-		} catch (DatatypeConfigurationException e) {
-			e.printStackTrace();
-		}
-		sender = getUser(username);
 		System.out.println("ID: " + sender.getID());
 	}
 
-	/**
+	private <T, R> R post(String uri, T body, Class<R> responseBodyClass) {
-	 * Creates a {@link Message} object serializable to XML.
+		javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
-	 * 
+		WebTarget					target	= client.target(uri);
-	 * @param textContent The content (text) of the message
-	 * @return prepared {@link Message} object
-	 */
-	public Message createMessage(String textContent) {
-		Message.Metadata metaData = objectFactory.createMessageMetadata();
-		metaData.setSender(sender.getID());
-		metaData.setRecipient(recipient.getID());
-		metaData.setState(MessageState.WAITING);
-		metaData.setDate(datatypeFactory.newXMLGregorianCalendar(Instant.now().toString()));
 
-		Message.Content content = objectFactory.createMessageContent();
+		Response	response		= target.request().post(Entity.entity(body, "application/xml"));
-		content.setType("text");
+		R			responseBody	= response.readEntity(responseBodyClass);
-		content.setText(textContent);
+		response.close();
+		client.close();
 
-		Message message = objectFactory.createMessage();
+		return responseBody;
-		message.setMetadata(metaData);
-		message.getContent().add(content);
-
-		return message;
 	}
 
 	/**
 	 * Returns a {@link Sync} with all users on the server.
+	 * 
 	 * @return Sync - List of all users on the server.
 	 * @since Envoy v0.1-alpha
 	 */
@@ -85,14 +64,11 @@ public class Client {
 		user.setID(-1);
 		sendSync.getUsers().add(user);
 
-		javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
+		Sync returnSendSync = post(
-		WebTarget					target	= client.target(String
+				String
-			.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0));
+					.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
-
+				sendSync,
-		Response	response		= target.request().post(Entity.entity(sendSync, "application/xml"));
+				Sync.class);
-		Sync		returnSendSync	= response.readEntity(Sync.class);
-		response.close();
-		client.close();
 		return returnSendSync;
 
 	}
@@ -110,20 +86,20 @@ public class Client {
 		user.setName(name);
 		senderSync.getUsers().add(user);
 
-		javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
+		Sync returnSenderSync = post(
-		WebTarget					target	= client.target(String
+				String
-			.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0));
+					.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
+				senderSync,
+				Sync.class);
+
+		User returnSender = objectFactory.createUser();
 
-		Response	response			= target.request().post(Entity.entity(senderSync, "application/xml"));
-		User		returnSender		= objectFactory.createUser();
-		Sync		returnSenderSync	= response.readEntity(Sync.class);
 		if (returnSenderSync.getUsers().size() == 1) {
 			returnSender = returnSenderSync.getUsers().get(0);
 		} else {
 			System.out.println("ERROR exiting...");
 		}
-		response.close();
+
-		client.close();
 		return returnSender;
 	}
 
@@ -131,300 +107,53 @@ public class Client {
 	 * Sends the "sync" Sync Object to the server and gets a "returnSync" Sync
 	 * Object as response. <br>
 	 * It is also used to get the own sender at the start of the client
-	 * (Client sends "sync" Sync Object with single user in it(name: the name entered at login, id: 0, UserStatus:null))<br>
+	 * (Client sends "sync" Sync Object with single user in it(name: the name
-	 *  and to get a complete list of all users saved on the server. 
+	 * entered at login, id: 0, UserStatus:null))<br>
-	 * (Client sends "sync" Sync Object with single user in it(name: "" (empty), id: -1, UserStatus:null)) <br>
+	 * and to get a complete list of all users saved on the server.
+	 * (Client sends "sync" Sync Object with single user in it(name: "" (empty), id:
+	 * -1, UserStatus:null)) <br>
 	 * This method also processes the response Sync Object. <br>
 	 * It sorts its users and messages by specific variables and does certain things
 	 * with them. <br>
 	 * <br>
 	 * Messages: <br>
-	 * -State SENT: 					Update Local message(s) with State WAITING (add Message ID and
+	 * -State SENT: Update Local message(s) with State WAITING (add Message ID and
-	 * 									change State to SENT). (server sends these informations to the client if
+	 * change State to SENT). (server sends these informations to the client if
-	 * 									message(s) with State WAITING were successfully sent to the server)<br>
+	 * message(s) with State WAITING were successfully sent to the server)<br>
-	 * -State RECEIVED, SenderID != 0: 	Adds the unread Messages returned from the
+	 * -State RECEIVED, SenderID != 0: Adds the unread Messages returned from the
-	 * 									server in the latest sync to the "unreadMessagesSync" Sync Object. <br>
+	 * server in the latest sync to the "unreadMessagesSync" Sync Object. <br>
-	 * -State RECEIVED, SenderID == 0: 	Update message(s) in localDB to state RECEIVED.
+	 * -State RECEIVED, SenderID == 0: Update message(s) in localDB to state
-	 * 									(server sends these informations to the client if the other client received
+	 * RECEIVED.
-	 * 									the message(s).) <br>
+	 * (server sends these informations to the client if the other client received
-	 * -State READ:						Update message(s) in the LocalDB to state READ. (server sends these informations to the client if the other client read
+	 * the message(s).) <br>
-	 * 									the message(s).) <br>
+	 * -State READ: Update message(s) in the LocalDB to state READ. (server sends
+	 * these informations to the client if the other client read
+	 * the message(s).) <br>
 	 * <br>
 	 * Users: <br>
-	 * Updating UserStatus of all users in LocalDB. (Server sends all users with their updated UserStatus to the client.) <br>						
+	 * Updating UserStatus of all users in LocalDB. (Server sends all users with
+	 * their updated UserStatus to the client.) <br>
 	 * 
 	 * @param userId
-	 * @param localDB
 	 * @since Envoy v0.1-alpha
 	 */
-	public void sendSync(long userId, LocalDB localDB) {
+	public Sync sendSync(long userId, Sync sync) {
-		new Thread(() -> {
+		// Print sync XML to console
-			// Print sync XML to console
+		JAXBContext jc;
-			JAXBContext jc;
+		try {
-			try {
+			jc = JAXBContext.newInstance("envoy.schema");
-				jc = JAXBContext.newInstance("envoy.schema");
+			Marshaller m = jc.createMarshaller();
-				Marshaller m = jc.createMarshaller();
+			m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
-				m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
+			m.marshal(sync, System.out);
-				m.marshal(sync, System.out);
+		} catch (JAXBException e) {
-			} catch (JAXBException e) {
+			e.printStackTrace();
-				e.printStackTrace();
-			}
-			addWaitingMessagesToSync(localDB);
-
-			getSentStateMessagesFromLocalDB(localDB);
-			for (int i = 0; i < readMessages.getMessages().size(); i++) {
-				sync.getMessages().add(readMessages.getMessages().get(i));
-			}
-			readMessages.getMessages().clear();
-
-			// Send sync
-			javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
-			WebTarget					target	= client
-				.target(String.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d",
-						config.getServer(),
-						config.getPort(),
-						userId));
-
-			Response response = target.request().post(Entity.entity(sync, "application/xml"));
-
-			Sync returnSync = response.readEntity(Sync.class);
-			if (returnSync.getMessages().size() != 0) {
-				System.out.println("Message ID: " + returnSync.getMessages().get(0).getMetadata().getMessageId());
-			}
-
-			for (int i = 0; i < returnSync.getMessages().size(); i++) {
-
-				// Print sync XML to console
-				JAXBContext jc2;
-				try {
-					jc2 = JAXBContext.newInstance("envoy.schema");
-					Marshaller m = jc2.createMarshaller();
-					m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
-					m.marshal(returnSync, System.out);
-				} catch (JAXBException e) {
-					e.printStackTrace();
-				}
-
-				if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
-						&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.SENT) {
-					// Update Local Messages with State WAITING (add Message ID and change State to
-					// SENT)
-					for (int j = 0; j < sync.getMessages().size(); j++) {
-						if (j == i) {
-							sync.getMessages()
-								.get(j)
-								.getMetadata()
-								.setMessageId(returnSync.getMessages().get(j).getMetadata().getMessageId());
-							sync.getMessages()
-								.get(j)
-								.getMetadata()
-								.setState(returnSync.getMessages().get(j).getMetadata().getState());
-						}
-
-					}
-
-				}
-				if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
-						&& returnSync.getMessages().get(i).getMetadata().getSender() != 0
-						&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.RECEIVED) {
-					// these are the unread Messages from the server
-					unreadMessagesSync.getMessages().add(returnSync.getMessages().get(i));
-
-				}
-
-				if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
-						&& returnSync.getMessages().get(i).getMetadata().getSender() == 0
-						&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.RECEIVED) {
-					// Update Messages in localDB to state RECEIVED
-					for (int j = 0; j < localDB.getChats().size(); j++) {
-						if (localDB.getChats().get(j).getRecipient().getID() == returnSync.getMessages()
-							.get(i)
-							.getMetadata()
-							.getRecipient()) {
-							for (int k = 0; k < localDB.getChats().get(j).getModel().getSize(); k++) {
-								if (localDB.getChats()
-									.get(j)
-									.getModel()
-									.get(k)
-									.getMetadata()
-									.getMessageId() == returnSync.getMessages().get(i).getMetadata().getMessageId()) {
-									// Update Message in LocalDB
-									localDB.getChats()
-										.get(j)
-										.getModel()
-										.get(k)
-										.getMetadata()
-										.setState(returnSync.getMessages().get(j).getMetadata().getState());
-								}
-							}
-						}
-					}
-
-				}
-
-				if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
-						&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.READ) {
-					// Update local Messages to state READ
-					System.out
-						.println("Message with ID: " + returnSync.getMessages().get(i).getMetadata().getMessageId()
-								+ "was initialized to be set to READ in localDB.");
-					for (int j = 0; j < localDB.getChats().size(); j++) {
-						if (localDB.getChats().get(j).getRecipient().getID() == returnSync.getMessages()
-							.get(i)
-							.getMetadata()
-							.getRecipient()) {
-							System.out.println(
-									"Chat with: " + localDB.getChats().get(j).getRecipient().getID() + "was selected.");
-							for (int k = 0; k < localDB.getChats().get(j).getModel().getSize(); k++) {
-								if (localDB.getChats()
-									.get(j)
-									.getModel()
-									.get(k)
-									.getMetadata()
-									.getMessageId() == returnSync.getMessages().get(i).getMetadata().getMessageId()) {
-									System.out.println("Message with ID: "
-											+ localDB.getChats().get(j).getModel().get(k).getMetadata().getMessageId()
-											+ "was selected.");
-									localDB.getChats()
-										.get(j)
-										.getModel()
-										.get(k)
-										.getMetadata()
-										.setState(returnSync.getMessages().get(i).getMetadata().getState());
-									System.out.println("Message State is now: " + localDB.getChats()
-										.get(j)
-										.getModel()
-										.get(k)
-										.getMetadata()
-										.getState()
-										.toString());
-								}
-							}
-						}
-					}
-
-				}
-			}
-
-			// Updating UserStatus of all Users in LocalDB
-			for (int j = 0; j < returnSync.getUsers().size(); j++) {
-				for (int k = 0; k < localDB.getChats().size(); k++) {
-					if (localDB.getChats().get(k).getRecipient().getID() == returnSync.getUsers().get(j).getID()) {
-
-						localDB.getChats().get(k).getRecipient().setStatus(returnSync.getUsers().get(j).getStatus());
-						System.out.println(localDB.getChats().get(k).getRecipient().getStatus().toString());
-					}
-				}
-			}
-
-			System.out.println("Response code: " + response.getStatus());
-
-			response.close();
-			client.close();
-			sync.getMessages().clear();
-			sync.getUsers().clear();
-
-		}).start();
-		System.out.println(sync.getMessages().size());
-
-	}
-
-	/**
-	 * Adds a message to the "sync" Sync object.
-	 * 
-	 * @param message
-	 * @since Envoy v0.1-alpha
-	 */
-	public void addMessageToSync(Message message) { sync.getMessages().add(message); }
-
-	/**
-	 * Adds a user to the "sync" Sync object.
-	 * 
-	 * @param user
-	 * @since Envoy v0.1-alpha
-	 */
-	public void addUserToSync(User user) { sync.getUsers().add(user); }
-
-	/**
-	 * Adds the unread Messages returned from the server in the latest sync to the
-	 * right chats in the LocalDB.
-	 * 
-	 * @param localDB
-	 * @since Envoy v0.1-alpha
-	 */
-	public void addUnreadMessagesToLocalDB(LocalDB localDB) {
-		Sync unreadMessages = unreadMessagesSync;
-		for (int i = 0; i < unreadMessages.getMessages().size(); i++)
-			for (int j = 0; j < localDB.getChats().size(); j++)
-				if (localDB.getChats().get(j).getRecipient().getID() == unreadMessages.getMessages()
-					.get(i)
-					.getMetadata()
-					.getSender()) {
-					localDB.getChats().get(j).appendMessage(unreadMessages.getMessages().get(i));
-				}
-	}
-
-	/**
-	 * Gets all Messages with state SENT from the LocalDB and adds them to the
-	 * "sync" Sync object.
-	 * 
-	 * @param localDB
-	 * @since Envoy v0.1-alpha
-	 */
-	public void getSentStateMessagesFromLocalDB(LocalDB localDB) {
-		for (int i = 0; i < localDB.getChats().size(); i++) {
-			for (int j = 0; j < localDB.getChats().get(i).getModel().getSize(); j++) {
-				if (localDB.getChats().get(i).getModel().get(j).getMetadata().getState() == MessageState.SENT) {
-					addMessageToSync(localDB.getChats().get(i).getModel().get(j));
-				}
-			}
 		}
-	}
 
-	/**
+		// Send sync
-	 * Changes all Messages with State RECEIVED of a specific chat to State READ.
+		return post(String
-	 * <br>
+			.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), userId),
-	 * Adds these Messages to the "readMessages" Sync object.
+				sync,
-	 * 
+				Sync.class);
-	 * @param currentChat
-	 * @since Envoy v0.1-alpha
-	 */
-	public void setMessagesToRead(Chat currentChat) {
-		for (int j = 0; j < currentChat.getModel().getSize(); j++) {
-			if (currentChat.getModel().get(j).getMetadata().getRecipient() != currentChat.getRecipient().getID()) {
-				if (currentChat.getModel().get(j).getMetadata().getState() == MessageState.RECEIVED) {
-					currentChat.getModel().get(j).getMetadata().setState(MessageState.READ);
-					readMessages.getMessages().add(currentChat.getModel().get(j));
-				}
-			}
-		}
-	}
-
-	/**
-	 * Adds a Message with State WAITING to a specific chat in the LocalDB.
-	 * 
-	 * @param message
-	 * @param currentChat
-	 * @since Envoy v0.1-alpha
-	 */
-	public void addWaitingMessageToLocalDB(Message message, Chat currentChat) { currentChat.appendMessage(message); }
-
-	/**
-	 * Adds all Messages with State WAITING from the LocalDB to the Sync.
-	 * 
-	 * @param localDB
-	 * @since Envoy v0.1-alpha
-	 */
-	public void addWaitingMessagesToSync(LocalDB localDB) {
-		for (int i = 0; i < localDB.getChats().size(); i++) {
-			for (int j = 0; j < localDB.getChats().get(i).getModel().getSize(); j++) {
-				if (localDB.getChats().get(i).getModel().get(j).getMetadata().getState() == MessageState.WAITING) {
-					// addMessageToSync(localDB.getChats().get(i).getModel().get(j));
-					System.out.println("Got Waiting Message");
-					sync.getMessages().add(0, localDB.getChats().get(i).getModel().get(j));
-				}
-			}
-		}
 	}
 
 	/**
@@ -453,10 +182,4 @@ public class Client {
 	 */
 	public boolean hasRecipient() { return recipient != null; }
 
-	/**
-	 * Clears the "unreadMessagesSync" Sync object.
-	 * 
-	 * @since Envoy v0.1-alpha
-	 */
-	public void clearUnreadMessagesSync() { unreadMessagesSync.getMessages().clear(); }
 }

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

@@ -6,11 +6,22 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBException;
+import javax.xml.bind.Marshaller;
+import javax.xml.datatype.DatatypeConfigurationException;
+import javax.xml.datatype.DatatypeFactory;
+
 import envoy.exception.EnvoyException;
+import envoy.schema.Message;
 import envoy.schema.User;
+import envoy.schema.Message.Metadata.MessageState;
+import envoy.schema.ObjectFactory;
+import envoy.schema.Sync;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -22,9 +33,11 @@ import envoy.schema.User;
  */
 public class LocalDB {
 
-	private File		localDB;
+	private File			localDB;
-	private User		sender;
+	private User			sender;
-	private List<Chat>	chats	= new ArrayList<>();
+	private List<Chat>		chats			= new ArrayList<>();
+	private ObjectFactory	objectFactory	= new ObjectFactory();
+	private DatatypeFactory	datatypeFactory;
 
 	/**
 	 * Constructs an empty local database.
@@ -32,7 +45,14 @@ public class LocalDB {
 	 * @param sender the user that is logged in with this client
 	 * @since Envoy v0.1-alpha
 	 **/
-	public LocalDB(User sender) { this.sender = sender; }
+	public LocalDB(User sender) {
+		this.sender = sender;
+		try {
+			datatypeFactory = DatatypeFactory.newInstance();
+		} catch (DatatypeConfigurationException e) {
+			e.printStackTrace();
+		}
+	}
 
 	/**
 	 * Initializes the local database and fills it with values
@@ -43,8 +63,8 @@ public class LocalDB {
 	 * @since Envoy v0.1-alpha
 	 **/
 	public void initializeDBFile(File localDBDir) throws EnvoyException {
-		if (localDBDir.exists() && !localDBDir.isDirectory())
+		if (localDBDir.exists() && !localDBDir.isDirectory()) throw new EnvoyException(
-			throw new EnvoyException(String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
+				String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
 		localDB = new File(localDBDir, sender.getID() + ".db");
 		if (localDB.exists()) loadFromLocalDB();
 	}
@@ -87,6 +107,276 @@ public class LocalDB {
 		}
 	}
 
+	// TODO
+	/**
+	 * Creates a {@link Message} object serializable to XML.
+	 * 
+	 * @param textContent The content (text) of the message
+	 * @return prepared {@link Message} object
+	 */
+	public Message createMessage(String textContent, User recipient) {
+		Message.Metadata metaData = objectFactory.createMessageMetadata();
+		metaData.setSender(sender.getID());
+		metaData.setRecipient(recipient.getID());
+		metaData.setState(MessageState.WAITING);
+		metaData.setDate(datatypeFactory.newXMLGregorianCalendar(Instant.now().toString()));
+
+		Message.Content content = objectFactory.createMessageContent();
+		content.setType("text");
+		content.setText(textContent);
+
+		Message message = objectFactory.createMessage();
+		message.setMetadata(metaData);
+		message.getContent().add(content);
+
+		return message;
+	}
+	
+	private Sync	unreadMessagesSync	= objectFactory.createSync();
+	public Sync		sync				= objectFactory.createSync();
+	public Sync		readMessages		= objectFactory.createSync();
+	
+	public Sync fillSync(long userId) {
+			
+			addWaitingMessagesToSync();
+
+			getSentStateMessagesFromLocalDB();
+			for (int i = 0; i < readMessages.getMessages().size(); i++) {
+				sync.getMessages().add(readMessages.getMessages().get(i));
+			}
+			readMessages.getMessages().clear();
+			
+
+		System.out.println(sync.getMessages().size());
+		return sync;
+	}
+	
+	public void applySync (Sync returnSync) {
+		for (int i = 0; i < returnSync.getMessages().size(); i++) {
+			if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
+					&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.SENT) {
+				// Update Local Messages with State WAITING (add Message ID and change State to
+				// SENT)
+				for (int j = 0; j < sync.getMessages().size(); j++) {
+					if (j == i) {
+						sync.getMessages()
+							.get(j)
+							.getMetadata()
+							.setMessageId(returnSync.getMessages().get(j).getMetadata().getMessageId());
+						sync.getMessages()
+							.get(j)
+							.getMetadata()
+							.setState(returnSync.getMessages().get(j).getMetadata().getState());
+					}
+	
+				}
+	
+			}
+			if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
+					&& returnSync.getMessages().get(i).getMetadata().getSender() != 0
+					&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.RECEIVED) {
+				// these are the unread Messages from the server
+				unreadMessagesSync.getMessages().add(returnSync.getMessages().get(i));
+	
+			}
+	
+			if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
+					&& returnSync.getMessages().get(i).getMetadata().getSender() == 0
+					&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.RECEIVED) {
+				// Update Messages in localDB to state RECEIVED
+				for (int j = 0; j < getChats().size(); j++) {
+					if (getChats().get(j).getRecipient().getID() == returnSync.getMessages()
+						.get(i)
+						.getMetadata()
+						.getRecipient()) {
+						for (int k = 0; k < getChats().get(j).getModel().getSize(); k++) {
+							if (getChats()
+								.get(j)
+								.getModel()
+								.get(k)
+								.getMetadata()
+								.getMessageId() == returnSync.getMessages().get(i).getMetadata().getMessageId()) {
+								// Update Message in LocalDB
+								getChats()
+									.get(j)
+									.getModel()
+									.get(k)
+									.getMetadata()
+									.setState(returnSync.getMessages().get(j).getMetadata().getState());
+							}
+						}
+					}
+				}
+	
+			}
+	
+			if (returnSync.getMessages().get(i).getMetadata().getMessageId() != 0
+					&& returnSync.getMessages().get(i).getMetadata().getState() == MessageState.READ) {
+				// Update local Messages to state READ
+				System.out
+					.println("Message with ID: " + returnSync.getMessages().get(i).getMetadata().getMessageId()
+							+ "was initialized to be set to READ in localDB.");
+				for (int j = 0; j < getChats().size(); j++) {
+					if (getChats().get(j).getRecipient().getID() == returnSync.getMessages()
+						.get(i)
+						.getMetadata()
+						.getRecipient()) {
+						System.out.println(
+								"Chat with: " + getChats().get(j).getRecipient().getID() + "was selected.");
+						for (int k = 0; k < getChats().get(j).getModel().getSize(); k++) {
+							if (getChats()
+								.get(j)
+								.getModel()
+								.get(k)
+								.getMetadata()
+								.getMessageId() == returnSync.getMessages().get(i).getMetadata().getMessageId()) {
+								System.out.println("Message with ID: "
+										+ getChats().get(j).getModel().get(k).getMetadata().getMessageId()
+										+ "was selected.");
+								getChats()
+									.get(j)
+									.getModel()
+									.get(k)
+									.getMetadata()
+									.setState(returnSync.getMessages().get(i).getMetadata().getState());
+								System.out.println("Message State is now: " + getChats()
+									.get(j)
+									.getModel()
+									.get(k)
+									.getMetadata()
+									.getState()
+									.toString());
+							}
+						}
+					}
+				}
+	
+			}
+		}
+
+		// Updating UserStatus of all Users in LocalDB
+		for (int j = 0; j < returnSync.getUsers().size(); j++) {
+			for (int k = 0; k < getChats().size(); k++) {
+				if (getChats().get(k).getRecipient().getID() == returnSync.getUsers().get(j).getID()) {
+	
+					getChats().get(k).getRecipient().setStatus(returnSync.getUsers().get(j).getStatus());
+					System.out.println(getChats().get(k).getRecipient().getStatus().toString());
+				}
+			}
+		}
+	
+		sync.getMessages().clear();
+		sync.getUsers().clear();
+
+	}
+
+	/**
+	 * Adds a message to the "sync" Sync object.
+	 * 
+	 * @param message
+	 * @since Envoy v0.1-alpha
+	 */
+	public void addMessageToSync(Message message) { sync.getMessages().add(message); }
+
+	/**
+	 * Adds a user to the "sync" Sync object.
+	 * 
+	 * @param user
+	 * @since Envoy v0.1-alpha
+	 */
+	public void addUserToSync(User user) { sync.getUsers().add(user); }
+
+	/**
+	 * Adds the unread Messages returned from the server in the latest sync to the
+	 * right chats in the LocalDB.
+	 * 
+	 * @param localDB
+	 * @since Envoy v0.1-alpha
+	 */
+	public void addUnreadMessagesToLocalDB() {
+		Sync unreadMessages = unreadMessagesSync;
+		for (int i = 0; i < unreadMessages.getMessages().size(); i++)
+			for (int j = 0; j < getChats().size(); j++)
+				if (getChats().get(j).getRecipient().getID() == unreadMessages.getMessages()
+					.get(i)
+					.getMetadata()
+					.getSender()) {
+					getChats().get(j).appendMessage(unreadMessages.getMessages().get(i));
+				}
+	}
+
+	/**
+	 * Gets all Messages with state SENT from the LocalDB and adds them to the
+	 * "sync" Sync object.
+	 * 
+	 * @param localDB
+	 * @since Envoy v0.1-alpha
+	 */
+	public void getSentStateMessagesFromLocalDB() {
+		for (int i = 0; i < getChats().size(); i++) {
+			for (int j = 0; j < getChats().get(i).getModel().getSize(); j++) {
+				if (getChats().get(i).getModel().get(j).getMetadata().getState() == MessageState.SENT) {
+					addMessageToSync(getChats().get(i).getModel().get(j));
+				}
+			}
+		}
+	}
+
+	/**
+	 * Changes all Messages with State RECEIVED of a specific chat to State READ.
+	 * <br>
+	 * Adds these Messages to the "readMessages" Sync object.
+	 * 
+	 * @param currentChat
+	 * @since Envoy v0.1-alpha
+	 */
+	public void setMessagesToRead(Chat currentChat) {
+		for (int j = 0; j < currentChat.getModel().getSize(); j++) {
+			if (currentChat.getModel().get(j).getMetadata().getRecipient() != currentChat.getRecipient().getID()) {
+				if (currentChat.getModel().get(j).getMetadata().getState() == MessageState.RECEIVED) {
+					currentChat.getModel().get(j).getMetadata().setState(MessageState.READ);
+					readMessages.getMessages().add(currentChat.getModel().get(j));
+				}
+			}
+		}
+	}
+
+	/**
+	 * Adds a Message with State WAITING to a specific chat in the LocalDB.
+	 * 
+	 * @param message
+	 * @param currentChat
+	 * @since Envoy v0.1-alpha
+	 */
+	public void addWaitingMessageToLocalDB(Message message, Chat currentChat) { currentChat.appendMessage(message); }
+
+	/**
+	 * Adds all Messages with State WAITING from the LocalDB to the Sync.
+	 * 
+	 * @param localDB
+	 * @since Envoy v0.1-alpha
+	 */
+	public void addWaitingMessagesToSync() {
+		for (int i = 0; i < getChats().size(); i++) {
+			for (int j = 0; j < getChats().get(i).getModel().getSize(); j++) {
+				if (getChats().get(i).getModel().get(j).getMetadata().getState() == MessageState.WAITING) {
+					// addMessageToSync(localDB.getChats().get(i).getModel().get(j));
+					System.out.println("Got Waiting Message");
+					sync.getMessages().add(0, getChats().get(i).getModel().get(j));
+				}
+			}
+		}
+	}
+	
+	
+	/**
+	 * Clears the "unreadMessagesSync" Sync object.
+	 * 
+	 * @since Envoy v0.1-alpha
+	 */
+	public void clearUnreadMessagesSync() { unreadMessagesSync.getMessages().clear(); }
+	
+
 	/**
 	 * @return all saves {@link Chat} objects that list the client user as the
 	 *         sender

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

@@ -30,7 +30,6 @@ import envoy.schema.Message;
 import envoy.schema.Sync;
 import envoy.schema.User;
 
-
 /**
  * Project: <strong>envoy-client</strong><br>
  * File: <strong>ChatWindow.java</strong><br>
@@ -156,8 +155,9 @@ public class ChatWindow extends JFrame {
 			if (!messageEnterTextfield.getText().isEmpty()) try {
 
 				// Create and send message object
-				final Message message = client.createMessage(messageEnterTextfield.getText());
+				final Message message = localDB.createMessage(messageEnterTextfield.getText(),
-				client.addWaitingMessageToLocalDB(message, currentChat);
+						currentChat.getRecipient());
+				localDB.addWaitingMessageToLocalDB(message, currentChat);
 				messageList.setModel(currentChat.getModel());
 
 				// Clear text field
@@ -214,8 +214,6 @@ public class ChatWindow extends JFrame {
 			}
 		});
 
-		
-		
 		userList.setSelectionForeground(new Color(255, 255, 255));
 		userList.setSelectionBackground(new Color(102, 0, 153));
 		userList.setForeground(new Color(255, 255, 255));
@@ -233,9 +231,8 @@ public class ChatWindow extends JFrame {
 		contentPane.add(userList, gbc_userList);
 		contentPane.revalidate();
 
-		
 		loadUsersAndChats();
-		startReceiverThread(5000);
+		startSyncThread(5000);
 
 		contentPane.revalidate();
 	}
@@ -266,20 +263,23 @@ public class ChatWindow extends JFrame {
 	 *                the server
 	 * @since Envoy v0.1-alpha
 	 */
-	private void startReceiverThread(int timeout) {
+	private void startSyncThread(int timeout) {
 		new Timer(timeout, (evt) -> {
-			if(currentChat != null) {
+			if (currentChat != null) { localDB.setMessagesToRead(currentChat); }
-				client.setMessagesToRead(currentChat);
-			}
-			client.sendSync(client.getSender().getID(), localDB);
-			client.addUnreadMessagesToLocalDB(localDB);
-			client.clearUnreadMessagesSync();
 
-			updateUserStates();
+			new Thread(() -> {
 
-			contentPane.revalidate();
+				// Synchronize
-			contentPane.repaint();
+				localDB.applySync(
+						client.sendSync(client.getSender().getID(), localDB.fillSync(client.getSender().getID())));
+				localDB.addUnreadMessagesToLocalDB();
+				localDB.clearUnreadMessagesSync();
+
+				// Update UI
+				SwingUtilities
+					.invokeLater(() -> { updateUserStates(); contentPane.revalidate(); contentPane.repaint(); });
 			}).start();
+		}).start();
 	}
 
 	private void updateUserStates() {