@Override
public void connection() {
try {
Configuration conf = DFSUtils.getConf(dir, null);
HdfsFileType fileType = DFSUtils.checkFileType(fs, new Path(dir), conf);
Class<? extends DfsReaderStrategy> recogniser = readerStrategyMap.get(fileType);
String name = recogniser.getName().substring(
recogniser.getName().lastIndexOf(".") + 1);
if (fileTypePrintVirgin) {
logger.info(String.format("Recognise filetype, use %s .", name));