Github user pnowojski commented on a diff in the pull request:
https://github.com/apache/flink/pull/6323#discussion_r202268019
--- Diff:
flink-connectors/flink-connector-kafka-base/src/main/java/org/apache/flink/streaming/connectors/kafka/KafkaTableSource.java
---
@@ -54,51 +56,105 @@
* override {@link #createKafkaConsumer(String, Properties,
DeserializationSchema)}}.
*/
@Internal
-public abstract class KafkaTableSource
- implements StreamTableSource<Row>, DefinedProctimeAttribute,
DefinedRowtimeAttributes {
+public abstract class KafkaTableSource implements
+ StreamTableSource<Row>,
+ DefinedProctimeAttribute,
+ DefinedRowtimeAttributes,
+ DefinedFieldMapping {
+
+ // common table source attributes
+ // TODO make all attributes final once we drop support for
format-specific table sources
/** The schema of the table. */
private final TableSchema schema;
+ /** Field name of the processing time attribute, null if no processing
time field is defined. */
+ private String proctimeAttribute;
+
+ /** Descriptor for a rowtime attribute. */
+ private List<RowtimeAttributeDescriptor> rowtimeAttributeDescriptors;
+
+ /** Mapping for the fields of the table schema to fields of the
physical returned type or null. */
+ private Map<String, String> fieldMapping;
+
+ // Kafka-specific attributes
+
/** The Kafka topic to consume. */
private final String topic;
/** Properties for the Kafka consumer. */
private final Properties properties;
- /** Type information describing the result type. */
- private TypeInformation<Row> returnType;
-
- /** Field name of the processing time attribute, null if no processing
time field is defined. */
- private String proctimeAttribute;
-
- /** Descriptor for a rowtime attribute. */
- private List<RowtimeAttributeDescriptor> rowtimeAttributeDescriptors;
+ /** Deserialization schema for decoding records from Kafka. */
+ private final DeserializationSchema<Row> deserializationSchema;
/** The startup mode for the contained consumer (default is {@link
StartupMode#GROUP_OFFSETS}). */
- private StartupMode startupMode = StartupMode.GROUP_OFFSETS;
+ private StartupMode startupMode;
/** Specific startup offsets; only relevant when startup mode is {@link
StartupMode#SPECIFIC_OFFSETS}. */
private Map<KafkaTopicPartition, Long> specificStartupOffsets;
/**
* Creates a generic Kafka {@link StreamTableSource}.
*
- * @param topic Kafka topic to consume.
- * @param properties Properties for the Kafka consumer.
- * @param schema Schema of the produced table.
- * @param returnType Type information of the produced
physical DataStream.
+ * @param schema Schema of the produced table.
+ * @param proctimeAttribute Field name of the processing time
attribute, null if no
--- End diff --
> null
`Optional` or overload or use builder or disallow null. Same applies to
classes that are extending from this one.
---
