private void registerDirectory ( Path dir ) throws IOException { Files . walkFileTree ( dir , new SimpleFileVisitor < Path > ( ) { @ Override public FileVisitResult preVisitDirectory ( Path dir , BasicFileAttributes attrs ) throws IOException { WatchKey key = dir . register ( watchService , ENTRY_CREATE , ENTRY_DELETE , ENTRY_MODIFY ) ; watchKeyToDirectory . put ( key , dir ) ; return FileVisitResult . CONTINUE ; } } ) ; }
Register the given directory and all its sub - directories .