code: public static void extractZipArchive( File zipFile, File targetDirectory )
  	throws IOException {
  
  		extractZipArchive( zipFile, targetDirectory, null, null );
  	}
docs: Extracts a ZIP archive in a directory.
  @param zipFile a ZIP file (not null, must exist)
  @param targetDirectory the target directory (may not exist but must be a directory)
  @throws IOException if something went wrong