Version

    Java interfaces for Joiners

    This is used in every Joiner, Map and DataIntersection.

    The transformation implements methods of the RecordTransform interface and inherits other common methods from the Transform interface. See Common Java interfaces.

    Following are the methods of the RecordTransform interface:

    • boolean init(Properties parameters, DataRecordMetadata[] sourcesMetadata, DataRecordMetadata[] targetMetadata)

      Initializes a transformation class/function. This method is called only once at the beginning of transformation process. Any object allocation/initialization should happen here.

    • int transform(DataRecord[] sources, DataRecord[] target)

      Performs transformation of source records to target records. This method is called as one step in transforming flow of records. For detailed information about return values and their meaning, see Return values of transformations.

    • int transformOnError(Exception exception, DataRecord[] sources, DataRecord[] target)

      Performs transformation of source records to target records. This method is called as one step in transforming flow of records. For detailed information about return values and their meaning, see Return values of transformations. Called only if transform(DataRecord[], DataRecord[]) throws an exception.

    • void signal(Object signalObject)

      A method which can be used for signalling into transformation that something outside happened. (For example in aggregation component key changed.)

    • Object getSemiResult()

      A method which can be used for getting intermediate results out of a transformation. May or may not be implemented.