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In Scala my DataProcessor is defined as
class DataProcessorKeyed extends CoProcessFunction[WineRecord, ModelToServe, Double] with CheckpointedFunction {
And it is used as follows
val models = modelsStream.map(ModelToServe.fromByteArray(_))
  .flatMap(BadDataHandler[ModelToServe])
  .keyBy(_.dataType)
val data = dataStream.map(DataRecord.fromByteArray(_))
  .flatMap(BadDataHandler[WineRecord])
  .keyBy(_.dataType)

// Merge streams
data
  .connect(models)
  .process(DataProcessorKeyed())
When I am doing the same thing in Java
public class DataProcessorKeyed extends CoProcessFunction<Winerecord.WineRecord, ModelToServe, Double> implements CheckpointedFunction{
Which I am using as follows
// Read data from streams
DataStream<Tuple2<String, ModelToServe>> models = modelsStream
        .flatMap(new ModelDataConverter(), new TupleTypeInfo<>(BasicTypeInfo.STRING_TYPE_INFO, TypeInformation.of(ModelToServe.class)))
        .keyBy(0);
DataStream<Tuple2<String, Winerecord.WineRecord>> data = dataStream
        .flatMap(new DataDataConverter(), new TupleTypeInfo<>(BasicTypeInfo.STRING_TYPE_INFO, TypeInformation.of(Winerecord.WineRecord.class)))
        .keyBy(0);

// Merge streams
data
        .connect(models)
        .process(new DataProcessorKeyed());
I am getting an error

Error:(68, 17) java: no suitable method found for keyBy(int)
    method org.apache.flink.streaming.api.scala.DataStream.keyBy(scala.collection.Seq<java.lang.Object>) is not applicable
      (argument mismatch; int cannot be converted to scala.collection.Seq<java.lang.Object>)
    method org.apache.flink.streaming.api.scala.DataStream.<K>keyBy(scala.Function1<org.apache.flink.api.java.tuple.Tuple2<java.lang.String,com.lightbend.model.ModelToServe>,K>,org.apache.flink.api.common.typeinfo.TypeInformation<K>) is not applicable
      (cannot infer type-variable(s) K
        (actual and formal argument lists differ in length))
So it assumes key/value pairs for the coprocessor

Why is such difference between APIs?

Boris Lublinsky
FDP Architect
[EMAIL PROTECTED]
https://www.lightbend.com/
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