Hi, are you using the WindowFunction in org.apache.flink.streaming.api.scala.function? It's a bit tricky because there is another WindowFunction in another package.
Cheers, Aljoscha On Tue, 13 Dec 2016 at 13:48 MIkkel Islay <my.inputstr...@gmail.com> wrote: > (The following is a cross-post of a Stack Overflow question at > https://stackoverflow.com/questions/41105142/windowfunction-extension-does-not-match-windowedstream-apply-signatures > ) > > Why does the below error occur? > > Given this extension to WindowFunction: > > class TestWinFunc extends WindowFunction[Top, Bottom, Long, TimeWindow] { > override def apply(key: Long, > w: TimeWindow, > iterable: Iterable[Top], > collector: Collector[Bottom]): Unit = { > collector.collect(Bottom(0.0,0.0,0.0,0.0,1L)) > } > } > > an *apply* transformation on a windowed stream: > > val bottom = inputstream > .keyBy(_.stamp) > .window(TumblingEventTimeWindows.of(Time.milliseconds(1))) > .apply(new TestWinFunc) > > yields the following error: > > Error:overloaded method value apply with alternatives: [R](function: > (Long, org.apache.flink.streaming.api.windowing.windows.TimeWindow, > Iterable[Flink.ETL.Top], org.apache.flink.util.Collector[R]) => > Unit)(implicit evidence$4: > org.apache.flink.api.common.typeinfo.TypeInformation[R])org.apache.flink.streaming.api.scala.DataStream[R] > [R](function: > org.apache.flink.streaming.api.scala.function.WindowFunction[Flink.ETL.Top,R,Long,org.apache.flink.streaming.api.windowing.windows.TimeWindow])(implicit > evidence$3: > org.apache.flink.api.common.typeinfo.TypeInformation[R])org.apache.flink.streaming.api.scala.DataStream[R] > cannot be applied to (Flink.ETL.TestWinFunc) .apply(new TestWinFunc) > > The 'bottom' val argument to *apply* has type WindowedStream[Top, Long, > TimeWindow]. > > Flink 1.1.3 / Scala 2.11 > > Thanks, > > Mikkel > >
