Fixed server not shutting down when using shutdown admin command; Added ShutdownService

src/services/ShutdownService.java

@@ -0,0 +1,108 @@
+package services;
+
+import intents.ServerStatusIntent;
+import intents.chat.ChatBroadcastIntent;
+import intents.chat.ChatBroadcastIntent.BroadcastType;
+
+import java.util.Locale;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import resources.control.Intent;
+import resources.control.ServerStatus;
+import resources.control.Service;
+import utilities.ThreadUtilities;
+
+public class ShutdownService extends Service {
+	
+	private static final String SHUTDOWN_MESSAGE = "The server will now be shutting down.";
+	private static final TimeUnit BROADCAST_UNIT = TimeUnit.NANOSECONDS;
+	
+	private final AtomicLong intervalCount;
+	private final AtomicLong timeRemaining;
+	private final AtomicInteger runCount;
+	private ScheduledExecutorService shutdownExecutor;
+	
+	public ShutdownService() {
+		intervalCount = new AtomicLong();
+		runCount = new AtomicInteger();
+		timeRemaining = new AtomicLong();
+		shutdownExecutor = null;
+	}
+	
+	@Override
+	public boolean initialize() {
+		registerForIntent(ServerStatusIntent.TYPE);
+		return super.initialize();
+	}
+	
+	@Override
+	public boolean terminate() {
+		shutdownExecutor();
+		return super.terminate();
+	}
+	
+	public void onIntentReceived(Intent i) {
+		if (!(i instanceof ServerStatusIntent))
+			return;
+		ServerStatusIntent ssi = (ServerStatusIntent) i;
+		if (ssi.getStatus() != ServerStatus.SHUTDOWN_REQUESTED)
+			return;
+		shutdown(ssi);
+	}
+	
+	private void shutdown(ServerStatusIntent i) {
+		final TimeUnit timeUnit = i.getTimeUnit();
+		final long time = i.getTime();
+		final long timeNanoSeconds = BROADCAST_UNIT.convert(time, timeUnit);
+		timeRemaining.set(time);
+		intervalCount.set((long) Math.ceil(Math.sqrt(Math.sqrt(timeNanoSeconds)) / 200));
+		
+		if (intervalCount.get() > timeNanoSeconds)
+			intervalCount.set(time);
+		
+		if (time > 0)
+			scheduleBroadcast(timeUnit, time, timeNanoSeconds / intervalCount.get());
+		else
+			broadcast(SHUTDOWN_MESSAGE);
+	}
+	
+	private void scheduleBroadcast(final TimeUnit timeUnit, final long time, final long timeBetweenBroadcasts) {
+		recreateExecutor();
+		shutdownExecutor.scheduleAtFixedRate(new Runnable() {
+			@Override
+			public void run() {
+				String message;
+				long timeRemainingVal = timeRemaining.get();
+				
+				if(runCount.getAndIncrement() == intervalCount.get()) {
+					message = SHUTDOWN_MESSAGE;
+				} else {
+					String unitName = timeUnit.name().toLowerCase(Locale.ENGLISH);
+					message = String.format("The server will be shutting down in %d %s", timeRemainingVal, unitName.substring(0, unitName.length() - 1));
+					message += (timeRemainingVal == 1 ? "" : "s") + ".";
+					timeRemaining.set(timeRemainingVal - timeUnit.convert(timeBetweenBroadcasts, BROADCAST_UNIT));
+				}
+				broadcast(message);
+			}
+		}, 0, timeBetweenBroadcasts, BROADCAST_UNIT);
+	}
+	
+	private void recreateExecutor() {
+		shutdownExecutor();
+		shutdownExecutor = Executors.newSingleThreadScheduledExecutor(ThreadUtilities.newThreadFactory("shutdown-service"));
+	}
+	
+	private void shutdownExecutor() {
+		if (shutdownExecutor != null)
+			shutdownExecutor.shutdownNow();
+	}
+	
+	private void broadcast(String message) {
+		new ChatBroadcastIntent(message, BroadcastType.GALAXY).broadcast();
+	}
+	
+}