@Override
    public HCatRecord next() {
      try {
        return curRecReader.getCurrentValue();
      } catch (IOException e) {
        throw new RuntimeException(e);
      } catch (InterruptedException e) {
        throw new RuntimeException(e);
      }
    }
This reader reads via {@link HCatInputFormat}
hcatalog/core/src/main/java/org/apache/hive/hcatalog/data/transfer/impl/HCatInputFormatReader.java