public DeserializationRuntimeConverter createNotNullConverter(
            LogicalType type,
            ZoneId serverTimeZone,
            DeserializationRuntimeConverterFactory userDefinedConverterFactory) {
        // user defined converter has a higher resolve order
        Optional<DeserializationRuntimeConverter> converter =
                userDefinedConverterFactory.createUserDefinedConverter(type, serverTimeZone);
        if (converter.isPresent()) {
            return converter.get();
        }

        // if no matched user defined converter, fallback to the default converter
        switch (type.getTypeRoot()) {
            case NULL:
                return new DeserializationRuntimeConverter() {

                    private static final long serialVersionUID = 1L;

                    @Override
                    public Object convert(Object dbzObj, Schema schema) {
                        return null;
                    }

                    @Override
                    public Object convert(Object dbzObj, Schema schema, TableChange tableSchema) throws Exception {
                        return convert(dbzObj, schema);
                    }
                };
            case BOOLEAN:
                return convertToBoolean();
            case TINYINT:
                return new DeserializationRuntimeConverter() {

                    private static final long serialVersionUID = 1L;

                    @Override
                    public Object convert(Object dbzObj, Schema schema) {
                        return Byte.parseByte(dbzObj.toString());
                    }

                    @Override
                    public Object convert(Object dbzObj, Schema schema, TableChange tableSchema) throws Exception {
                        return convert(dbzObj, schema);
                    }
                };
            case SMALLINT:
                return new DeserializationRuntimeConverter() {

                    private static final long serialVersionUID = 1L;

                    @Override
                    public Object convert(Object dbzObj, Schema schema) {
                        return Short.parseShort(dbzObj.toString());
                    }

                    @Override
                    public Object convert(Object dbzObj, Schema schema, TableChange tableSchema) throws Exception {
                        return convert(dbzObj, schema);
                    }
                };
            case INTEGER:
            case INTERVAL_YEAR_MONTH:
                return convertToInt();
            case BIGINT:
            case INTERVAL_DAY_TIME:
                return convertToLong();
            case DATE:
                return convertToDate();
            case TIME_WITHOUT_TIME_ZONE:
                return convertToTime();
            case TIMESTAMP_WITHOUT_TIME_ZONE:
                return convertToTimestamp(serverTimeZone);
            case TIMESTAMP_WITH_LOCAL_TIME_ZONE:
                return convertToLocalTimeZoneTimestamp(serverTimeZone);
            case FLOAT:
                return convertToFloat();
            case DOUBLE:
                return convertToDouble();
            case CHAR:
            case VARCHAR:
                return convertToString();
            case BINARY:
            case VARBINARY:
                return convertToBinary();
            case DECIMAL:
                return createDecimalConverter((DecimalType) type);
            case ROW:
                return createRowConverter(
                        (RowType) type, serverTimeZone, userDefinedConverterFactory);
            case ARRAY:
            case MAP:
            case MULTISET:
            case RAW:
            default:
                throw new UnsupportedOperationException("Unsupported type: " + type);
        }
    }
Creates a runtime converter which assuming input object is not null.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/oracle-cdc/src/main/java/org/apache/inlong/sort/cdc/oracle/debezium/table/RowDataDebeziumDeserializeSchema.java