@Override
  public WriteContext init(final Configuration configuration) {
    conf = configuration;
    schema = getSchema(configuration);
    Map<String, String> metaData = new HashMap<>();
    metaData.put(WRITER_TIMEZONE, TimeZone.getDefault().toZoneId().toString());
    defaultDateProleptic = HiveConf.getBoolVar(
        configuration, HiveConf.ConfVars.HIVE_PARQUET_DATE_PROLEPTIC_GREGORIAN);
    metaData.put(WRITER_DATE_PROLEPTIC, String.valueOf(defaultDateProleptic));
    metaData.put(WRITER_ZONE_CONVERSION_LEGACY, String
        .valueOf(HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVE_PARQUET_TIMESTAMP_WRITE_LEGACY_CONVERSION_ENABLED)));
    return new WriteContext(schema, metaData);
  }
DataWritableWriteSupport is a WriteSupport for the DataWritableWriter
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/write/DataWritableWriteSupport.java