@Override
  public Object getPrimitiveWritableObject(final Object o) {
    return o == null ? null : new ShortWritable(get(o));
  }
The ParquetShortInspector can inspect both ShortWritables and IntWritables into shorts.
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/serde/primitive/ParquetShortInspector.java