private File initCacheDirectory(File cacheDirectory){
  try {
    if (cacheDirectory == null) {
      Path tempDirectory=Files.createTempDirectory(DEFAULT_CACHE_PREFIX);
      return tempDirectory.toFile();
    }
 else {
      cacheDirectory.mkdirs();
      return cacheDirectory;
    }
  }
 catch (  IOException e) {
    throw new IllegalArgumentException("Unable to create cache directory",e);
  }
}

private File initCacheDirectory ( File cacheDirectory ) { try { if ( cacheDirectory == null ) { Path tempDirectory = Files . createTempDirectory ( DEFAULT_CACHE_PREFIX ) ; return tempDirectory . toFile ( ) ; } else { cacheDirectory . mkdirs ( ) ; return cacheDirectory ; } } catch ( IOException e ) { throw new IllegalArgumentException ( "Unable to create cache directory" , e ) ; } }
handles init operation of a local cache directory .
