Merge pull request #22 from informatik-ag-ngl/f/sync

Sync

.classpath

@@ -18,12 +18,6 @@
 			<attribute name="test" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources">
-		<attributes>
-			<attribute name="maven.pomderived" value="true"/>
-			<attribute name="test" value="true"/>
-		</attributes>
-	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>

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

@@ -1,8 +1,5 @@
 package envoy.client;
 
-import java.time.Instant;
-import java.util.Arrays;
-
 import javax.ws.rs.client.ClientBuilder;
 import javax.ws.rs.client.Entity;
 import javax.ws.rs.client.WebTarget;
@@ -10,15 +7,10 @@ import javax.ws.rs.core.Response;
 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.schema.Message;
-import envoy.schema.Message.MetaData.MessageState;
-import envoy.schema.Messages;
 import envoy.schema.ObjectFactory;
+import envoy.schema.Sync;
 import envoy.schema.User;
-import envoy.schema.Users;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -33,89 +25,47 @@ import envoy.schema.Users;
 public class Client {
 
 	private ObjectFactory	objectFactory	= new ObjectFactory();
-	private DatatypeFactory	datatypeFactory;
 	private Config			config;
 	private User			sender, recipient;
 
 	public Client(Config config, String username) {
-		this.config = config;
+		this.config	= config;
-		try {
+		sender		= getUser(username);
-			datatypeFactory = DatatypeFactory.newInstance();
+		System.out.println("ID: " + sender.getID());
-		} catch (DatatypeConfigurationException e) {
+	}
-			e.printStackTrace();
+
-		}
+	private <T, R> R post(String uri, T body, Class<R> responseBodyClass) {
-		sender = getUser(username);
+		javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
+		WebTarget					target	= client.target(uri);
+
+		Response	response		= target.request().post(Entity.entity(body, "application/xml"));
+		R			responseBody	= response.readEntity(responseBodyClass);
+		response.close();
+		client.close();
+
+		return responseBody;
+
 	}
 
 	/**
-	 * Sends a message with text content to the server.<br>
+	 * Returns a {@link Sync} with all users on the server.
-	 * Because sending a request is a blocking operation, it is executed
-	 * asynchronously.
 	 * 
-	 * @param message the {@link Message} we want to send
+	 * @return Sync - List of all users on the server.
 	 * @since Envoy v0.1-alpha
 	 */
-	public void sendMessage(Message message) {
+	public Sync getUsersListXml() {
-		new Thread(() -> {
+		Sync	sendSync	= objectFactory.createSync();
-			// Wrap single message into messages list
+		User	user		= objectFactory.createUser();
-			Messages messages = wrapMessages(message);
+		user.setID(-1);
+		sendSync.getUsers().add(user);
 
-			// Print message XML to console
+		Sync returnSendSync = post(
-			JAXBContext jc;
+				String
-			try {
+					.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
-				jc = JAXBContext.newInstance("envoy.schema");
+				sendSync,
-				Marshaller m = jc.createMarshaller();
+				Sync.class);
-				m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
+		return returnSendSync;
-				m.marshal(messages, System.out);
-			} catch (JAXBException e) {
-				e.printStackTrace();
-			}
 
-			// Send message
-			javax.ws.rs.client.Client	client	= ClientBuilder.newClient();
-			WebTarget					target	= client
-				.target(String.format("%s:%d/envoy-server/rest/message/send", config.getServer(), config.getPort()));
-
-			Response response = target.request().post(Entity.entity(messages, "application/xml"));
-			System.out.println("Response code: " + response.getStatus());
-			response.close();
-			client.close();
-		}).start();
-	}
-
-	/**
-	 * Creates a {@link Message} object serializable to XML.
-	 * 
-	 * @param textContent The content (text) of the message
-	 * @return prepared {@link Message} object
-	 * @since Envoy v0.1-alpha
-	 */
-	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();
-		content.setType("text");
-		content.setText(textContent);
-
-		Message message = objectFactory.createMessage();
-		message.setMetaData(metaData);
-		message.getContent().add(content);
-
-		return message;
-	}
-
-	public Users getUsersListXml() {
-		return get(String.format("%s:%d/envoy-server/rest/user", config.getServer(), config.getPort()), Users.class);
-	}
-
-	public Messages getUnreadMessages(long userId) {
-		return get(String
-			.format("%s:%d/envoy-server/rest/message/receive?userId=%d", config.getServer(), config.getPort(), userId),
-				Messages.class);
 	}
 
 	/**
@@ -126,66 +76,104 @@ public class Client {
 	 * @since Envoy v0.1-alpha
 	 */
 	private User getUser(String name) {
-		return get(
+		Sync	senderSync	= objectFactory.createSync();
+		User	user		= objectFactory.createUser();
+		user.setName(name);
+		senderSync.getUsers().add(user);
+
+		Sync returnSenderSync = post(
 				String
-					.format("%s:%d/envoy-server/rest/user/sender?name=%s", config.getServer(), config.getPort(), name),
+					.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
-				Users.class).getUser().get(0);
+				senderSync,
+				Sync.class);
+
+		User returnSender = objectFactory.createUser();
+
+		if (returnSenderSync.getUsers().size() == 1) {
+			returnSender = returnSenderSync.getUsers().get(0);
+		} else {
+			System.out.println("ERROR exiting...");
+		}
+
+		return returnSender;
 	}
 
 	/**
-	 * Invokes the GET method of a web service.
+	 * 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>
+	 * 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
+	 * change State to SENT). (server sends these informations to the client if
+	 * message(s) with State WAITING were successfully sent to the server)<br>
+	 * -State RECEIVED, SenderID != 0: Adds the unread Messages returned from the
+	 * server in the latest sync to the "unreadMessagesSync" Sync Object. <br>
+	 * -State RECEIVED, SenderID == 0: Update message(s) in localDB to state
+	 * RECEIVED.
+	 * (server sends these informations to the client if the other client received
+	 * 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>
 	 * 
-	 * @param <T>           the type of the object returned by the web service
+	 * @param userId
-	 * @param uri           the URI of the web service
-	 * @param responseClass the class of the object returned by the web service
-	 * @return the object returned by the web service
 	 * @since Envoy v0.1-alpha
 	 */
-	private <T> T get(String uri, Class<T> responseClass) {
+	public Sync sendSync(long userId, Sync sync) {
-		javax.ws.rs.client.Client	client			= ClientBuilder.newClient();
+		// Print sync XML to console
-		WebTarget					target			= client.target(uri);
+		JAXBContext jc;
-		Response					response		= target.request("application/xml").get();
+		try {
-		T							responseObject	= response.readEntity(responseClass);
+			jc = JAXBContext.newInstance("envoy.schema");
-		System.out.println("Response code: " + response.getStatus());
+			Marshaller m = jc.createMarshaller();
-		response.close();
+			m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
-		client.close();
+			m.marshal(sync, System.out);
-		return responseObject;
+		} catch (JAXBException e) {
+			e.printStackTrace();
+		}
+
+		// Send sync
+		return post(String
+			.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), userId),
+				sync,
+				Sync.class);
 	}
 
 	/**
-	 * Wraps one or more {@link Message} objects into a {@link Messages} object.
+	 * @return the sender object that represents this client.
-	 * 
-	 * @param messages the {@link Message} objects to wrap
-	 * @return {@link Messages} object with all messages as its children
-	 * @since Envoy v0.1-alpha
-	 */
-	private Messages wrapMessages(Message... messages) {
-		Messages wrapper = objectFactory.createMessages();
-		wrapper.getMessage().addAll(Arrays.asList(messages));
-		return wrapper;
-	}
-
-	/**
-	 * @return the sender object that represents this client
 	 * @since Envoy v0.1-alpha
 	 */
 	public User getSender() { return sender; }
 
 	/**
-	 * @return the recipient of a message
+	 * @return the current recipient of the current chat.
 	 * @since Envoy v0.1-alpha
 	 */
 	public User getRecipient() { return recipient; }
 
 	/**
-	 * @param recipient the recipient to set
+     * Sets the recipient.
+	 * @param recipient - the recipient to set
 	 * @since Envoy v0.1-alpha
 	 */
 	public void setRecipient(User recipient) { this.recipient = recipient; }
 
-	/**
+    /**
 	 * @return true, if a recipient is selected
 	 * @since Envoy v0.1-alpha
 	 */
 	public boolean hasRecipient() { return recipient != null; }
 }
+

src/main/java/envoy/client/Config.java

@@ -16,6 +16,16 @@ public class Config {
 	private String	server;
 	private int		port;
 	private File	localDB;
+	private int		syncTimeout;
+
+	private static Config config;
+
+	private Config() {}
+
+	public static Config getInstance() {
+		if (config == null) config = new Config();
+		return config;
+	}
 
 	/**
 	 * Defaults to the {@code client.properties} file for information.
@@ -28,7 +38,8 @@ public class Config {
 	public void load(Properties properties) {
 		if (properties.containsKey("server")) server = properties.getProperty("server");
 		if (properties.containsKey("port")) port = Integer.parseInt(properties.getProperty("port"));
-		localDB = new File(properties.getProperty("localDB", ".\\localDB"));
+		localDB		= new File(properties.getProperty("localDB", ".\\localDB"));
+		syncTimeout	= Integer.parseInt(properties.getProperty("syncTimeout", "1000"));
 	}
 
 	/**
@@ -53,6 +64,8 @@ public class Config {
 				case "-db":
 					localDB = new File(args[++i]);
 			}
+		if (localDB == null) localDB = new File(".\\localDB");
+		if (syncTimeout == 0) syncTimeout = 1000;
 	}
 
 	/**
@@ -107,4 +120,8 @@ public class Config {
 	 * @since Envoy v0.1-alpha
 	 **/
 	public void setLocalDB(File localDB) { this.localDB = localDB; }
+
+	public int getSyncTimeout() { return syncTimeout; }
+
+	public void setSyncTimeout(int syncTimeout) { this.syncTimeout = syncTimeout; }
 }

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

@@ -6,10 +6,18 @@ 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.datatype.DatatypeConfigurationException;
+import javax.xml.datatype.DatatypeFactory;
+
 import envoy.exception.EnvoyException;
+import envoy.schema.Message;
+import envoy.schema.Message.Metadata.MessageState;
+import envoy.schema.ObjectFactory;
+import envoy.schema.Sync;
 import envoy.schema.User;
 
 /**
@@ -18,13 +26,15 @@ import envoy.schema.User;
  * Created: <strong>27.10.2019</strong><br>
  *
  * @author Kai S. K. Engelbart
+ * @author Maximilian K&auml;fer
  * @since Envoy v0.1-alpha
  */
 public class LocalDB {
-
+	private File			localDB;
-	private File		localDB;
+	private User			sender;
-	private User		client;
+	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 +42,16 @@ public class LocalDB {
 	 * @param client the user that is logged in with this client
 	 * @since Envoy v0.1-alpha
 	 **/
-	public LocalDB(User sender) { this.client = 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
@@ -45,7 +64,7 @@ public class LocalDB {
 	public void initializeDBFile(File localDBDir) throws EnvoyException {
 		if (localDBDir.exists() && !localDBDir.isDirectory()) throw new EnvoyException(
 				String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
-		localDB = new File(localDBDir, client.getID() + ".db");
+		localDB = new File(localDBDir, sender.getID() + ".db");
 		if (localDB.exists()) loadFromLocalDB();
 	}
 
@@ -87,6 +106,256 @@ public class LocalDB {
 		}
 	}
 
+	/**
+	 * 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 {@code sync} {@link 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 {@code readMessages} {@link Sync} object.
+	 * 
+	 * @param currentChat
+	 * @since Envoy v0.1-alpha
+	 */
+	public void setMessagesToRead(Chat currentChat) {
+		for (int i = currentChat.getModel().size() - 1; i >= 0; --i)
+			if (currentChat.getModel().get(i).getMetadata().getRecipient() != currentChat.getRecipient().getID())
+				if (currentChat.getModel().get(i).getMetadata().getState() == MessageState.RECEIVED) {
+					currentChat.getModel().get(i).getMetadata().setState(MessageState.READ);
+					readMessages.getMessages().add(currentChat.getModel().get(i));
+				} else break;
+	}
+
+	/**
+	 * 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 {@link 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 {@code unreadMessagesSync} {@link 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
 	 *         client
@@ -98,5 +367,5 @@ public class LocalDB {
 	 * @return the User who initialised the local Database
 	 * @since Envoy v0.1-alpha
 	 */
-	public User getUser() { return client; }
+	public User getUser() { return sender; }
 }

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

@@ -27,11 +27,11 @@ import javax.swing.border.EmptyBorder;
 
 import envoy.client.Chat;
 import envoy.client.Client;
+import envoy.client.Config;
 import envoy.client.LocalDB;
 import envoy.schema.Message;
-import envoy.schema.Messages;
+import envoy.schema.Sync;
 import envoy.schema.User;
-import envoy.schema.Users;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -125,8 +125,8 @@ public class ChatWindow extends JFrame {
 
 				if (e.getKeyCode() == KeyEvent.VK_ENTER && ((SettingsScreen.enterToSend && e.getModifiersEx() == 0)
 						|| (e.getModifiersEx() == KeyEvent.CTRL_DOWN_MASK))) {
-					postMessage(client, messageList);
 
+					postMessage(messageList);
 				}
 
 			}
@@ -164,8 +164,7 @@ public class ChatWindow extends JFrame {
 
 		gbc_moveSelectionPostButton.insets = new Insets(10, 10, 10, 10);
 
-		postButton.addActionListener((evt) -> { postMessage(client, messageList); });
+		postButton.addActionListener((evt) -> { postMessage(messageList); });
-
 		contentPane.add(postButton, gbc_moveSelectionPostButton);
 
 		// Settings Button
@@ -223,9 +222,13 @@ public class ChatWindow extends JFrame {
 					.findFirst()
 					.get();
 
+				// Set all unread messages in the chat to read
+				if (currentChat != null) { localDB.setMessagesToRead(currentChat); }
+
 				client.setRecipient(user);
 
 				textPane.setText(currentChat.getRecipient().getName());
+
 				messageList.setModel(currentChat.getModel());
 				contentPane.revalidate();
 			}
@@ -249,37 +252,24 @@ public class ChatWindow extends JFrame {
 		contentPane.revalidate();
 
 		loadUsersAndChats();
-		startReceiverThread(5000);
+		startSyncThread(Config.getInstance().getSyncTimeout());
 
 		contentPane.revalidate();
 	}
 
-	/**
+	private void postMessage(JList<Message> messageList) {
-	 * Posts a {@link Message}. Is used only twice: Once for clicking on the
-	 * {@code postButton}<br>
-	 * and once for pressing the KeyStroke(s) to send a message ( (ctrl+)enter)
-	 * 
-	 * @param client      the client who wants to send a {@link Message}
-	 * @param messageList the chat in which this {@link Message} belongs
-	 * @since Envoy v0.1-alpha
-	 */
-	private void postMessage(Client client, JList<Message> messageList) {
 		if (!client.hasRecipient()) {
 			JOptionPane.showMessageDialog(this,
 					"Please select a recipient!",
 					"Cannot send message",
 					JOptionPane.INFORMATION_MESSAGE);
-			return;
 		}
 
 		if (!messageEnterTextArea.getText().isEmpty()) try {
 
 			// Create and send message object
-			final Message message = client.createMessage(messageEnterTextArea.getText());
+			final Message message = localDB.createMessage(messageEnterTextArea.getText(), currentChat.getRecipient());
-			client.sendMessage(message);
+			localDB.addWaitingMessageToLocalDB(message, currentChat);
-
-			// Append message object to chat
-			currentChat.appendMessage(message);
 			messageList.setModel(currentChat.getModel());
 
 			// Clear text field
@@ -302,9 +292,9 @@ public class ChatWindow extends JFrame {
 	 */
 	private void loadUsersAndChats() {
 		new Thread(() -> {
-			Users					users			= client.getUsersListXml();
+			Sync					users			= client.getUsersListXml();
 			DefaultListModel<User>	userListModel	= new DefaultListModel<>();
-			users.getUser().forEach(user -> {
+			users.getUsers().forEach(user -> {
 				userListModel.addElement(user);
 
 				// Check if user exists in local DB
@@ -316,21 +306,33 @@ public class ChatWindow extends JFrame {
 	}
 
 	/**
-	 * Checks for new messages and adds them to the chat list.
+	 * Updates the data model and the ui every x seconds.
 	 * 
 	 * @param timeout the amount of time that passes between two requests sent to
 	 *                the server
 	 * @since Envoy v0.1-alpha
 	 */
-	private void startReceiverThread(int timeout) {
+	private void startSyncThread(int timeout) {
 		new Timer(timeout, (evt) -> {
-			Messages unreadMessages = client.getUnreadMessages(client.getSender().getID());
+			new Thread(() -> {
-			for (int i = 0; i < unreadMessages.getMessage().size(); i++)
+
-				for (int j = 0; j < localDB.getChats().size(); j++)
+				// Synchronize
-					if (localDB.getChats().get(j).getRecipient().getID() == unreadMessages.getMessage()
+				localDB.applySync(
-						.get(i)
+						client.sendSync(client.getSender().getID(), localDB.fillSync(client.getSender().getID())));
-						.getMetaData()
+				localDB.addUnreadMessagesToLocalDB();
-						.getSender()) localDB.getChats().get(j).appendMessage(unreadMessages.getMessage().get(i));
+				localDB.clearUnreadMessagesSync();
+
+				// Update UI
+				SwingUtilities
+					.invokeLater(() -> { updateUserStates(); contentPane.revalidate(); contentPane.repaint(); });
+			}).start();
 		}).start();
 	}
+
+	private void updateUserStates() {
+		for (int i = 0; i < userList.getModel().getSize(); i++)
+			for (int j = 0; j < localDB.getChats().size(); j++)
+				if (userList.getModel().getElementAt(i).getID() == localDB.getChats().get(j).getRecipient().getID())
+					userList.getModel().getElementAt(i).setStatus(localDB.getChats().get(j).getRecipient().getStatus());
+	}
 }

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

@@ -18,6 +18,7 @@ import envoy.schema.Message;
  * Created: <strong>19 Oct 2019</strong><br>
  * 
  * @author Kai S. K. Engelbart
+ * @author Maximilian K&auml;fer
  * @since Envoy v0.1-alpha
  */
 public class MessageListRenderer extends JLabel implements ListCellRenderer<Message> {
@@ -38,14 +39,16 @@ public class MessageListRenderer extends JLabel implements ListCellRenderer<Mess
 		setOpaque(true);
 
 		final String	text	= value.getContent().get(0).getText();
-		final String	date	= value.getMetaData().getDate() == null ? ""
+		final String 	state 	= value.getMetadata().getState().toString();
-				: new SimpleDateFormat("dd.MM.yyyy hh:mm ")
+		final String	date	= value.getMetadata().getDate() == null ? ""
-					.format(value.getMetaData().getDate().toGregorianCalendar().getTime());
+				: new SimpleDateFormat("dd.MM.yyyy HH:mm ")
+					.format(value.getMetadata().getDate().toGregorianCalendar().getTime());
 
 		setText(String.format(
-				"<html><p style=\"color:#d2d235\"><b><small>%s</b></small><br><p style=\"color:white\">%s</html>",
+				"<html><p style=\"color:#d2d235\"><b><small>%s</b></small><br><p style=\"color:white\">%s :%s</html>",
 				date,
-				text));
+				text,
+				state));
 		return this;
 	}
 }

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

@@ -25,7 +25,7 @@ import envoy.exception.EnvoyException;
 public class Startup {
 
 	public static void main(String[] args) {
-		Config config = new Config();
+		Config config = Config.getInstance();
 		if (args.length > 0) {
 			config.load(args);
 		} else {

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

@@ -7,6 +7,7 @@ import javax.swing.JList;
 import javax.swing.ListCellRenderer;
 
 import envoy.schema.User;
+import envoy.schema.User.UserStatus;
 
 /**
  * Defines how the {@code UserList} is displayed.
@@ -16,6 +17,7 @@ import envoy.schema.User;
  * Created: <strong>12 Oct 2019</strong><br>
  * 
  * @author Kai S. K. Engelbart
+ * @author Maximilian K&auml;fer
  * @since Envoy v0.1-alpha
  */
 public class UserListRenderer extends JLabel implements ListCellRenderer<User> {
@@ -36,8 +38,27 @@ public class UserListRenderer extends JLabel implements ListCellRenderer<User> {
 		// Enable background rendering
 		setOpaque(true);
 
-		setText(value.getName());
+
-		setFont(list.getFont());
+		final String		name	= value.getName();
+		final UserStatus	status	= value.getStatus();
+		
+		switch (status) {
+			case ONLINE:
+				setText(String.format(
+						"<html><p style=\"color:#03fc20\"><b><small>%s</b></small><br><p style=\"color:white\">%s</html>",
+						status,
+						name));
+				break;
+
+			case OFFLINE:
+				setText(String.format(
+						"<html><p style=\"color:#fc0303\"><b><small>%s</b></small><br><p style=\"color:white\">%s</html>",
+						status,
+						name));
+				break;
+		}
+
+		
 
 		return this;
 	}