Replaced MessageCache by Cache<T>

This class will be used to implement the offline cache for both messages
and events.

src/main/java/envoy/client/data/Cache.java

@@ -0,0 +1,58 @@
+package envoy.client.data;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.function.Consumer;
+import java.util.logging.Logger;
+
+import envoy.client.util.EnvoyLog;
+
+/**
+ * Stores elements in a queue to process them later.<br>
+ * <br>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>Cache.java</strong><br>
+ * Created: <strong>6 Feb 2020</strong><br>
+ *
+ * @param <T> the type of cached elements
+ * @author Kai S. K. Engelbart
+ * @since Envoy v0.3-alpha
+ */
+public class Cache<T> implements Consumer<T> {
+
+	private final Queue<T>	elements	= new LinkedList<>();
+	private Consumer<T>		processor;
+
+	private static final Logger logger = EnvoyLog.getLogger(Cache.class.getSimpleName());
+
+	/**
+	 * Adds an element to the cache.
+	 *
+	 * @param element the element to add
+	 * @since Envoy v0.3-alpha
+	 */
+	@Override
+	public void accept(T element) {
+		logger.info(String.format("Adding element %s to cache", element));
+		elements.offer(element);
+	}
+
+	/**
+	 * Sets the processor to which cached elements are relayed.
+	 *
+	 * @param processor the processor to set
+	 * @since Envoy v0.3-alpha
+	 */
+	public void setProcessor(Consumer<T> processor) { this.processor = processor; }
+
+	/**
+	 * Relays all cached elements to the processor.
+	 *
+	 * @throws IllegalStateException if the processor is not initialized
+	 * @since Envoy v0.3-alpha
+	 */
+	public void relay() {
+		if (processor == null) throw new IllegalStateException("Processor is not defined");
+		elements.forEach(processor::accept);
+	}
+}

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

@@ -10,6 +10,7 @@ import java.util.logging.Logger;
 import javax.naming.TimeLimitExceededException;
 
 import envoy.client.Config;
+import envoy.client.data.Cache;
 import envoy.client.data.LocalDb;
 import envoy.client.util.EnvoyLog;
 import envoy.data.*;
@@ -61,7 +62,7 @@ public class Client implements Closeable {
 	 *                   failed for some other reason
 	 * @since Envoy v0.2-alpha
 	 */
-	public MessageCache onlineInit(LoginCredentials credentials, LocalDb localDb) throws Exception {
+	public Cache<Message> onlineInit(LoginCredentials credentials, LocalDb localDb) throws Exception {
 		// Establish TCP connection
 		logger.info(String.format("Attempting connection to server %s:%d...", config.getServer(), config.getPort()));
 		socket = new Socket(config.getServer(), config.getPort());
@@ -71,7 +72,7 @@ public class Client implements Closeable {
 		receiver = new Receiver(socket.getInputStream());
 
 		// Create cache for unread messages
-		final MessageCache cache = new MessageCache();
+		final Cache<Message> cache = new Cache<>();
 
 		// Register user creation processor, contact list processor and message cache
 		receiver.registerProcessor(User.class, sender -> { logger.info("Acquired user object " + sender); this.sender = sender; });

src/main/java/envoy/client/net/MessageCache.java

@@ -1,54 +0,0 @@
-package envoy.client.net;
-
-import java.util.LinkedList;
-import java.util.Queue;
-import java.util.function.Consumer;
-import java.util.logging.Logger;
-
-import envoy.client.util.EnvoyLog;
-import envoy.data.Message;
-
-/**
- * Stores messages in a queue until the application initialization is complete.
- * The messages can then be relayed to a processor.<br>
- * <br>
- * Project: <strong>envoy-client</strong><br>
- * File: <strong>MessageCache.java</strong><br>
- * Created: <strong>4 Feb 2020</strong><br>
- *
- * @author Kai S. K. Engelbart
- * @since Envoy v0.3-alpha
- */
-public class MessageCache implements Consumer<Message> {
-
-	private final Queue<Message>	messages	= new LinkedList<>();
-	private Consumer<Message>		processor;
-
-	private static final Logger logger = EnvoyLog.getLogger(MessageCache.class.getSimpleName());
-
-	/**
-	 * Adds a message to the cache.
-	 *
-	 * @since Envoy v0.3-alpha
-	 */
-	@Override
-	public void accept(Message message) {
-		logger.info(String.format("Adding message %s to cache", message));
-		messages.add(message);
-	}
-
-	/**
-	 * Sets the processor to which messages are relayed.
-	 *
-	 * @param processor the processor to set
-	 * @since Envoy v0.3-alpha
-	 */
-	public void setProcessor(Consumer<Message> processor) { this.processor = processor; }
-
-	/**
-	 * Relays all cached messages to the processor.
-	 *
-	 * @since Envoy v0.3-alpha
-	 */
-	public void relayMessages() { messages.forEach(processor::accept); }
-}

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

@@ -13,13 +13,11 @@ import javax.swing.SwingUtilities;
 
 import envoy.client.Config;
 import envoy.client.Settings;
-import envoy.client.data.LocalDb;
+import envoy.client.data.*;
-import envoy.client.data.PersistentLocalDb;
-import envoy.client.data.TransientLocalDb;
 import envoy.client.net.Client;
-import envoy.client.net.MessageCache;
 import envoy.client.util.EnvoyLog;
 import envoy.data.LoginCredentials;
+import envoy.data.Message;
 import envoy.data.User;
 import envoy.exception.EnvoyException;
 
@@ -108,7 +106,7 @@ public class Startup {
 		// Acquire the client user (with ID) either from the server or from the local
 		// database, which triggers offline mode
 		Client			client	= new Client();
-		MessageCache	cache	= null;
+		Cache<Message>	cache	= null;
 		try {
 			// Try entering online mode first
 			localDb.loadIdGenerator();
@@ -178,7 +176,7 @@ public class Startup {
 		});
 
 		// Relay unread messages from cache
-		if (cache != null) cache.relayMessages();
+		if (cache != null) cache.relay();
 
 		// Save Settings and PersistentLocalDb on shutdown
 		Runtime.getRuntime().addShutdownHook(new Thread(() -> {