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