Implemented offline mode for Client and LocalDB

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

@@ -1,6 +1,7 @@
 package envoy.client;
 
-import java.util.logging.Logger;
+import java.util.HashMap;
+import java.util.Map;
 
 import javax.ws.rs.client.ClientBuilder;
 import javax.ws.rs.client.Entity;
@@ -32,13 +33,11 @@ public class Client {
 	private User			sender, recipient;
 	private boolean			online			= false;
 
-	private static final Logger logger = Logger.getLogger(Client.class.getSimpleName());
+	public Client(Config config) { this.config = config; }
 
-	public Client(Config config, String userName) throws EnvoyException {
+	public void onlineInit(String userName) throws EnvoyException {
-		this.config	= config;
+		sender	= getUser(userName);
-		sender		= getUser(userName);
+		online	= true;
-		
-		logger.info("Client user ID: " + sender.getID());
 	}
 
 	private <T, R> R post(String uri, T body, Class<R> responseBodyClass) {
@@ -53,22 +52,25 @@ public class Client {
 	}
 
 	/**
-	 * Returns a {@link Sync} with all users on the server.
+	 * Returns a {@code Map<String, User>} of all users on the server with their
+	 * user names as keys.
 	 * 
 	 * @return Sync - List of all users on the server.
-	 * @since Envoy v0.1-alpha
+	 * @since Envoy v0.2-alpha
 	 */
-	public Sync getUsersListXml() {
+	public Map<String, User> getUsers() {
 		Sync	sendSync	= objectFactory.createSync();
 		User	user		= objectFactory.createUser();
 		user.setID(-1);
 		sendSync.getUsers().add(user);
 
-		Sync returnSendSync = post(String.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
+		Sync returnSync = post(String.format("%s:%d/envoy-server/rest/sync/syncData?userId=%d", config.getServer(), config.getPort(), 0),
 				sendSync,
 				Sync.class);
-		return returnSendSync;
 
+		Map<String, User> users = new HashMap<>();
+		returnSync.getUsers().forEach(u -> users.put(u.getName(), u));
+		return users;
 	}
 
 	/**
@@ -160,6 +162,8 @@ public class Client {
 	 */
 	public User getSender() { return sender; }
 
+	public void setSender(User sender) { this.sender = sender; }
+
 	/**
 	 * @return the current recipient of the current chat.
 	 * @since Envoy v0.1-alpha

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

@@ -8,7 +8,9 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.logging.Logger;
 
 import javax.xml.datatype.DatatypeConfigurationException;
@@ -34,9 +36,9 @@ import envoy.schema.User;
  */
 public class LocalDB {
 
-	private File		localDBFile, usersFile;
+	private File		localDBDir, localDBFile, usersFile;
 	private User		user;
-	private List<User>	users	= new ArrayList<>();
+	private Map<String, User>	users	= new HashMap<>();
 	private List<Chat>	chats	= new ArrayList<>();
 
 	private ObjectFactory	objectFactory	= new ObjectFactory();
@@ -54,12 +56,19 @@ public class LocalDB {
 	 *
 	 * @since Envoy v0.1-alpha
 	 */
-	public LocalDB() {
+	public LocalDB(File localDBDir) throws IOException {
+		this.localDBDir = localDBDir;
+		
 		try {
 			datatypeFactory = DatatypeFactory.newInstance();
 		} catch (DatatypeConfigurationException e) {
 			e.printStackTrace();
 		}
+		
+		// Initialize local database directory
+		if (localDBDir.exists() && !localDBDir.isDirectory())
+			throw new IOException(String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
+		usersFile	= new File(localDBDir, "users.db");
 	}
 
 	/**
@@ -70,18 +79,9 @@ public class LocalDB {
 	 * @throws EnvoyException if the directory selected is not an actual directory.
 	 * @since Envoy v0.1-alpha
 	 */
-	public void initializeDBFile(File localDBDir) throws EnvoyException {
+	public void initializeDBFile() throws EnvoyException {
 		if (user == null) throw new NullPointerException("Client user is null");
-		if (localDBDir.exists() && !localDBDir.isDirectory())
-			throw new EnvoyException(String.format("LocalDBDir '%s' is not a directory!", localDBDir.getAbsolutePath()));
-		usersFile	= new File(localDBDir, "users.db");
 		localDBFile	= new File(localDBDir, user.getID() + ".db");
-		try {
-			loadUsers();
-			loadChats();
-		} catch (ClassNotFoundException | IOException e) {
-			throw new EnvoyException(e);
-		}
 	}
 
 	/**
@@ -99,7 +99,7 @@ public class LocalDB {
 	}
 
 	@SuppressWarnings("unchecked")
-	private void loadUsers() throws ClassNotFoundException, IOException { users = read(usersFile, ArrayList.class); }
+	public void loadUsers() throws ClassNotFoundException, IOException { users = read(usersFile, HashMap.class); }
 
 	/**
 	 * Loads all chats saved by Envoy for the client user.
@@ -110,7 +110,7 @@ public class LocalDB {
 	 * @since Envoy v0.1-alpha
 	 */
 	@SuppressWarnings("unchecked")
-	private void loadChats() throws ClassNotFoundException, IOException { chats = read(localDBFile, ArrayList.class); }
+	public void loadChats() throws ClassNotFoundException, IOException { chats = read(localDBFile, ArrayList.class); }
 
 	private <T> T read(File file, Class<T> serializedClass) throws ClassNotFoundException, IOException {
 		try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(file))) {
@@ -308,12 +308,12 @@ public class LocalDB {
 	/**
 	 * @return the users
 	 */
-	public List<User> getUsers() { return users; }
+	public Map<String, User> getUsers() { return users; }
 
 	/**
 	 * @param users the users to set
 	 */
-	public void setUsers(List<User> users) { this.users = users; }
+	public void setUsers(Map<String, User> users) { this.users = users; }
 
 	/**
 	 * @return all saved {@link Chat} objects that list the client user as the

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

@@ -34,7 +34,6 @@ import envoy.client.Config;
 import envoy.client.LocalDB;
 import envoy.client.Settings;
 import envoy.schema.Message;
-import envoy.schema.Sync;
 import envoy.schema.User;
 
 /**
@@ -132,8 +131,7 @@ public class ChatWindow extends JFrame {
 			@Override
 			public void keyReleased(KeyEvent e) {
 				if (e.getKeyCode() == KeyEvent.VK_ENTER
-						&& ((Settings.getInstance().isEnterToSend() && e.getModifiersEx() == 0)
+						&& ((Settings.getInstance().isEnterToSend() && e.getModifiersEx() == 0) || (e.getModifiersEx() == KeyEvent.CTRL_DOWN_MASK))) {
-								|| (e.getModifiersEx() == KeyEvent.CTRL_DOWN_MASK))) {
 					postMessage(messageList);
 				}
 			}
@@ -181,8 +179,8 @@ public class ChatWindow extends JFrame {
 		settingsButton.addActionListener((evt) -> {
 			try {
 				SettingsScreen.open();
-				changeChatWindowColors(Settings.getInstance().getCurrentTheme());			
+				changeChatWindowColors(Settings.getInstance().getCurrentTheme());
-                } catch (Exception e) {
+			} catch (Exception e) {
 				SettingsScreen.open();
 				logger.log(Level.WARNING, "An error occured while opening the settings screen", e);
 				e.printStackTrace();
@@ -235,7 +233,7 @@ public class ChatWindow extends JFrame {
 		gbc_userList.insets	= new Insets(space, space, space, space);
 
 		changeChatWindowColors(Settings.getInstance().getCurrentTheme());
-        
+
 		contentPane.add(userList, gbc_userList);
 		contentPane.revalidate();
 
@@ -244,7 +242,6 @@ public class ChatWindow extends JFrame {
 
 		contentPane.revalidate();
 	}
-	
 
 	/**
 	 * Used to immediately reload the ChatWindow when settings were changed.
@@ -287,18 +284,14 @@ public class ChatWindow extends JFrame {
 
 	private void postMessage(JList<Message> messageList) {
 		if (!client.hasRecipient()) {
-			JOptionPane.showMessageDialog(this,
+			JOptionPane.showMessageDialog(this, "Please select a recipient!", "Cannot send message", JOptionPane.INFORMATION_MESSAGE);
-					"Please select a recipient!",
-					"Cannot send message",
-					JOptionPane.INFORMATION_MESSAGE);
 			return;
 		}
 
 		if (!messageEnterTextArea.getText().isEmpty()) try {
 
 			// Create and send message object
-			final Message message = localDB.createMessage(messageEnterTextArea.getText(),
+			final Message message = localDB.createMessage(messageEnterTextArea.getText(), currentChat.getRecipient().getID());
-					currentChat.getRecipient().getID());
 			currentChat.appendMessage(message);
 			messageList.setModel(currentChat.getModel());
 
@@ -322,9 +315,8 @@ public class ChatWindow extends JFrame {
 	 */
 	private void loadUsersAndChats() {
 		new Thread(() -> {
-			Sync					users			= client.getUsersListXml();
+			DefaultListModel<User> userListModel = new DefaultListModel<>();
-			DefaultListModel<User>	userListModel	= new DefaultListModel<>();
+			localDB.getUsers().values().forEach(user -> {
-			users.getUsers().forEach(user -> {
 				userListModel.addElement(user);
 
 				// Check if user exists in local DB
@@ -348,8 +340,7 @@ public class ChatWindow extends JFrame {
 			new Thread(() -> {
 
 				// Synchronize
-				localDB.applySync(
+				localDB.applySync(client.sendSync(client.getSender().getID(), localDB.fillSync(client.getSender().getID())));
-						client.sendSync(client.getSender().getID(), localDB.fillSync(client.getSender().getID())));
 
 				// Process unread messages
 				localDB.addUnreadMessagesToLocalDB();
@@ -359,8 +350,7 @@ public class ChatWindow extends JFrame {
 				readCurrentChat();
 
 				// Update UI
-				SwingUtilities
+				SwingUtilities.invokeLater(() -> { updateUserStates(); contentPane.revalidate(); contentPane.repaint(); });
-					.invokeLater(() -> { updateUserStates(); contentPane.revalidate(); contentPane.repaint(); });
 			}).start();
 		}).start();
 	}
@@ -377,4 +367,3 @@ public class ChatWindow extends JFrame {
 	 */
 	private void readCurrentChat() { if (currentChat != null) { localDB.setMessagesToRead(currentChat); } }
 }
-

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

@@ -1,6 +1,7 @@
 package envoy.client.ui;
 
 import java.awt.EventQueue;
+import java.io.IOException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -10,6 +11,7 @@ import envoy.client.Client;
 import envoy.client.Config;
 import envoy.client.LocalDB;
 import envoy.exception.EnvoyException;
+import envoy.schema.User;
 
 /**
  * Starts the Envoy client and prompts the user to enter their name.
@@ -54,32 +56,61 @@ public class Startup {
 			logger.severe("User name is not set or empty. Exiting...");
 			System.exit(1);
 		}
-
+		
-		// Acquire the client user (with ID) either from the server or from the local
+		// Initialize the local database
-		// database, which triggers offline mode
+		LocalDB localDB;
-		Client client;
 		try {
-			client = new Client(config, userName);
+			localDB = new LocalDB(config.getLocalDB());
-		} catch (Exception e1) {
+		} catch (IOException e3) {
-			logger.log(Level.SEVERE, "Failed to acquire client user ID", e1);
+			logger.log(Level.SEVERE, "Could not initialize local database", e3);
-			JOptionPane.showMessageDialog(null, e1.toString(), "Client error", JOptionPane.ERROR_MESSAGE);
+			JOptionPane.showMessageDialog(null, "Could not initialize local database!\n" + e3.toString());
 			System.exit(1);
 			return;
 		}
 
-		// Load the local database
+		// Acquire the client user (with ID) either from the server or from the local
-		LocalDB localDB = new LocalDB();
+		// database, which triggers offline mode
-		localDB.setUser(client.getSender());
+		Client client = new Client(config);
 		try {
-			localDB.initializeDBFile(config.getLocalDB());
+			// Try entering online mode first
-		} catch (EnvoyException e) {
+			client.onlineInit(userName);
+		} catch (Exception e1) {
+			logger.warning("Could not connect to server. Trying offline mode...");
+			try {
+				// Try entering offline mode
+				localDB.loadUsers();
+				User clientUser = localDB.getUsers().get(userName);
+				if(clientUser == null)
+					throw new EnvoyException("Could not enter offline mode: user name unknown");
+				client.setSender(clientUser);
+			} catch(Exception e2) {
+				JOptionPane.showMessageDialog(null, e1.toString(), "Client error", JOptionPane.ERROR_MESSAGE);
+				System.exit(1);
+				return;
+			}
+		}
+		
+		// Set client user in local database
+		localDB.setUser(client.getSender());
+		
+		// Initialize chats in local database
+		try {
+			localDB.initializeDBFile();
+			localDB.loadChats();
+		} catch (EnvoyException | ClassNotFoundException | IOException e) {
 			e.printStackTrace();
 			JOptionPane.showMessageDialog(null,
 					"Error while loading local database: " + e.toString() + "\nChats will not be stored locally.",
 					"Local DB error",
 					JOptionPane.WARNING_MESSAGE);
 		}
+		
+		logger.info("Client user ID: " + client.getSender().getID());
 
+		// Save all users to the local database
+		if(client.isOnline())
+			localDB.setUsers(client.getUsers());
+		
 		EventQueue.invokeLater(() -> {
 			try {
 				ChatWindow chatWindow = new ChatWindow(client, localDB);