RxFileWatcher allows you to observe directories (recursively or not) for file system events with a RxJava observable. It is based on the JDK WatchService, but it is much more convenient.

Usage

The following example creates an observable that watches the given directory and all its subdirectories for file system events. Directories which are created later are watched, too. Each event will be emitted as a WatchEvent.

PathObservables
  .watchRecursive(Paths.get("some/directory/"))
  .subscribe(event -> System.out.println(event));

To watch only the top-level directory, you call watchNonRecursive instead of watchRecursive:

PathObservables
  .watchNonRecursive(Paths.get("some/directory/"))
  .subscribe(event -> System.out.println(event));

That's it!

See RxJava Documentation for more information, e. g. how you can filter certain types of events.