private RowDataToFieldConverter createNotNullConverter(LogicalType type) {
        switch (type.getTypeRoot()) {
            case NULL:
                return inputObj -> null;
            case BOOLEAN:
            case BINARY:
            case VARBINARY:
            case TINYINT:
            case SMALLINT:
            case INTEGER:
            case INTERVAL_YEAR_MONTH:
            case FLOAT:
            case DOUBLE:
            case BIGINT:
            case INTERVAL_DAY_TIME:
                return inputObj -> inputObj;
            case CHAR:
            case VARCHAR:
                return Object::toString;
            case DATE:
                return createDateConverter();
            case TIME_WITHOUT_TIME_ZONE:
                return createTimeConverter();
            case TIMESTAMP_WITHOUT_TIME_ZONE:
                return createTimestampConverter();
            case TIMESTAMP_WITH_LOCAL_TIME_ZONE:
                return createTimestampWithLocalZone();
            case DECIMAL:
                return inputObj -> ((DecimalData) inputObj).toBigDecimal();
            case ARRAY:
                return createArrayConverter((ArrayType) type);
            case MAP:
                MapType mapType = (MapType) type;
                return createMapConverter(mapType.asSummaryString(), mapType.getKeyType(), mapType.getValueType());
            case MULTISET:
                MultisetType multisetType = (MultisetType) type;
                return createMapConverter(multisetType.asSummaryString(), multisetType.getElementType(),
                        new IntType());
            case ROW:
                return createRowConverter((RowType) type);
            case RAW:
            default:
                throw new UnsupportedOperationException("Not support to parse type: " + type);
        }
    }
Creates a runtime converter which assuming input object is not null.
inlong-sort/sort-formats/format-rowdata/format-rowdata-json/src/main/java/org/apache/inlong/sort/formats/json/RowDataToFieldConverters.java