@Override
            public void addFloat(final float value) {
              if ((value >= minValue) && (value <= maxValue) && (value % 1 == 0)) {
                parent.set(index, new LongWritable((long) value));
              } else {
                parent.set(index, null);
              }
            }
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