@Override
              public void addLong(final long value) {
                Timestamp timestamp =
                    ParquetTimestampUtils.getTimestamp(value, logicalType.getUnit(), logicalType.isAdjustedToUTC());
                parent.set(index, new TimestampWritableV2(timestamp));
              }
ETypeConverter is an easy way to set the converter for the right type.
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/convert/ETypeConverter.java