Hey Ankur, Add the following line to your imports, and have a look at the referenced FAQ. [1]
import org.apache.flink.streaming.api.scala._ [1] https://flink.apache.org/faq.html#in-scala-api-i-get-an-error-about-implicit-values-and-evidence-parameters Best, Marton On Sun, Mar 6, 2016 at 8:17 PM, Ankur Sharma <an...@stud.uni-saarland.de> wrote: > Hello, > > I am trying to use a custom source function (declaration given below) for > DataStream. > if I add the source to stream using add source: > > val stream = env.addSource(new QueryOneSource(args)) > > *I get following error: Any explanations and help ??* > > > Error:(14, 31) could not find implicit value for evidence parameter of type > org.apache.flink.api.common.typeinfo.TypeInformation[org.mpi.debs.Tuple] > > val stream = env.addSource(new QueryOneSource(args)) > > ^ > > Error:(14, 31) not enough arguments for method addSource: (implicit > evidence$15: scala.reflect.ClassTag[org.mpi.debs.Tuple], implicit > evidence$16: > org.apache.flink.api.common.typeinfo.TypeInformation[org.mpi.debs.Tuple])org.apache.flink.streaming.api.scala.DataStream[org.mpi.debs.Tuple]. > > Unspecified value parameter evidence$16. > > val stream = env.addSource(new QueryOneSource(args)) > > ^ > > > class QueryOneSource(filenames: Array[String]) extends SourceFunction[Tuple] { > > val nextTuple: Tuple // case class Tuple(id: Long, value: Int) > > override def run(ctx: SourceContext[Tuple]) = { > while (true) { > nextRecord() > ctx.collect(this.nextTuple) > } > } > > override def cancel() = { } > > } > > override def nextRecord() = { > > } > > } > > Best, > *Ankur Sharma* > *Information Systems Group* > *3.15 E1.1 Universität des Saarlandes* > *66123, Saarbrücken Germany* > *Email: ankur.sha...@mpi-inf.mpg.de <ankur.sha...@mpi-inf.mpg.de> * > * an...@stud.uni-saarland.de <an...@stud.uni-saarland.de>* > >
