@Override
  public Path getPath() {
    if (inputSplits != null && inputSplits.length > 0
        && inputSplits[0] instanceof FileSplit) {
      return ((FileSplit) inputSplits[0]).getPath();
    }
    return new Path("");
  }
HiveInputSplit encapsulates an InputSplit with its corresponding
inputFormatClass. The reason that it derives from FileSplit is to make sure
"map.input.file" in MapTask.
ql/src/java/org/apache/hadoop/hive/ql/io/BucketizedHiveInputSplit.java