close method

gistfile1.java

/**
 * Method that closes this file channel gracefully without loosing any data.
 */
@Override
public void close() throws IOException {
	AsynchronousFileChannel writeableChannel = innerChannel;
	System.out.println("Starting graceful shutdown ...");
	closeLock.lock();
	try {
		state = PREPARE;
		innerChannel = AsynchronousFileChannel.open(Paths.get(uri),
				new HashSet<StandardOpenOption>(Arrays.asList(StandardOpenOption.READ)), pool);
		System.out.println("Channel blocked for write access ...");
		if (!pool.getQueue().isEmpty()) {
			System.out.println("Waiting for signal that queue is empty ...");
			isEmpty.await();
			System.out.println("Received signal that queue is empty ... closing");
		} else {
			System.out.println("Don't have to wait, queue is empty ...");
		}
	} catch (InterruptedException e) {
		Thread.interrupted();
		throw new RuntimeException("Interrupted on awaiting Empty-Signal!", e);
	} catch (Exception e) {
		throw new RuntimeException("Unexpected error" + e);
	} finally {
		closeLock.unlock();
		writeableChannel.force(false);
		writeableChannel.close(); // close the writable channel
		innerChannel.close(); // close the read-only channel
		System.out.println("File closed ...");
		pool.shutdown(); // allow clean up tasks from previous close() operation to finish safely
		try {
			pool.awaitTermination(1, TimeUnit.MINUTES);
		} catch (InterruptedException e) {
			Thread.interrupted();
			throw new RuntimeException("Could not terminate thread pool!", e);
		}
		System.out.println("Pool closed ...");
	}
}