public static boolean areInSync(File source,
    File destination) throws IOException 
{
 // 16 MB
		if ( source.isDirectory() ) {
			if ( !destination.exists() ) {
				return false;
			}
			else if ( !destination.isDirectory() ) {
				throw new IOException(
						"Source and Destination not of the same type:"
								+ source.getCanonicalPath() + " , " + destination.getCanonicalPath()
				);
			}
			String[] sources = source.list();
			Set< String > srcNames = new HashSet< String >( Arrays.asList( sources ) );
			String[] dests = destination.list();
			// check for files in destination and not in source
			for ( String fileName : dests ) {
				if ( !srcNames.contains( fileName ) ) {
					return false;
				}
			}
			boolean inSync = true;
			for ( String fileName : sources ) {
				File srcFile = new File( source, fileName );
				File destFile = new File( destination, fileName );
				if ( !areInSync( srcFile, destFile ) ) {
					inSync = false;
					break;
				}
			}
			return inSync;
		}
		else {
			if ( destination.exists() && destination.isFile() ) {
				long sts = source.lastModified() / FAT_PRECISION;
				long dts = destination.lastModified() / FAT_PRECISION;
				return sts == dts;
			}
			else {
				return false;
			}
		}
}

 public static  void delete(File file) 
{
		if ( file.isDirectory() ) {
			for ( File subFile : file.listFiles() ) {
				delete( subFile );
			}
		}
		if ( file.exists() ) {
			if ( !file.delete() ) {
				log.error( "Could not delete {}", file );
			}
		}
}

 public static  void synchronize(File source,
    File destination,
    boolean smart) throws IOException 
{
		synchronize( source, destination, smart, DEFAULT_COPY_BUFFER_SIZE );
}

 public static  void synchronize(File source,
    File destination,
    boolean smart,
    long chunkSize) throws IOException 
{
		if ( chunkSize < = 0 ) {
			log.warn( "Chunk size must be positive: using default value." );
			chunkSize = DEFAULT_COPY_BUFFER_SIZE;
		}
		if ( source.isDirectory() ) {
			if ( !destination.exists() ) {
				if ( !destination.mkdirs() ) {
					throw new IOException( "Could not create path " + destination );
				}
			}
			else if ( !destination.isDirectory() ) {
				throw new IOException(
						"Source and Destination not of the same type:"
								+ source.getCanonicalPath() + " , " + destination.getCanonicalPath()
				);
			}
			String[] sources = source.list();
			Set< String > srcNames = new HashSet< String >( Arrays.asList( sources ) );
			String[] dests = destination.list();
			//delete files not present in source
			for ( String fileName : dests ) {
				if ( !srcNames.contains( fileName ) ) {
					delete( new File( destination, fileName ) );
				}
			}
			//copy each file from source
			for ( String fileName : sources ) {
				File srcFile = new File( source, fileName );
				File destFile = new File( destination, fileName );
				synchronize( srcFile, destFile, smart, chunkSize );
			}
		}
		else {
			if ( destination.exists() && destination.isDirectory() ) {
				delete( destination );
			}
			if ( destination.exists() ) {
				long sts = source.lastModified() / FAT_PRECISION;
				long dts = destination.lastModified() / FAT_PRECISION;
				//do not copy if smart and same timestamp and same length
				if ( !smart || sts == 0 || sts != dts || source.length() != destination.length() ) {
					copyFile( source, destination, chunkSize );
				}
			}
			else {
				copyFile( source, destination, chunkSize );
			}
		}
}