File sdCard = Environment.getExternalStorageDirectory();
 Observable<FileEvent> sdCardFileEvents = RxFileObserver.create(sdCard);
 sdCardFileEvents.subscribe(new Action1<FileEvent>() {

  @Override
  public void call(FileEvent fileEvent) {

Log.i(TAG, fileEvent.toString());

  
}
 
}
);

EnumSet<FileEventType> eventTypeEnumSet; String path;

public enum FileEventType {

  ACCESS, // Data was read from a file
  MODIFY, // Data was written to a file
  ATTRIB, // Metadata (permissions, owner, timestamp) was changed explicitly
  CLOSE_WRITE, // Someone had a file or directory open for writing, and closed it
  CLOSE_NOWRITE, // Someone had a file or directory open read-only, and closed it
  OPEN, // A file or directory was opened
  MOVED_FROM, // A file or subdirectory was moved from the monitored directory
  MOVED_TO, // A file or subdirectory was moved to the monitored directory
  CREATE, // A new file or subdirectory was created under the monitored directory
  DELETE, // A file was deleted from the monitored directory
  DELETE_SELF, // The monitored file or directory was deleted; monitoring effectively stops
  MOVE_SELF; // The monitored file or directory was moved; monitoring continues
  (...) 
}