Have you checked your logs whether they contain some problems? In general it is not recommended collecting the streaming result back to your client. It might also be a problem with `DataStreamUtils.collect`.
Cheers, Till On Tue, Jul 19, 2016 at 2:42 PM, subash basnet <yasub...@gmail.com> wrote: > Hello all, > > I tried to check if it works for tuple but same problem, the collection > still shows blank result. I took the id of centroid tuple and printed it, > but the collection displays empty. > > DataStream<Centroid> centroids = newCentroidDataStream.map(new > TupleCentroidConverter()); > DataStream<Tuple1<String>> centroidId = centroids.map(new TestMethod()); > centroidId.print(); > Iterator<Tuple1<String>> iter = DataStreamUtils.collect(centroidId); > Collection<Tuple1<String>> testCentroids = Lists.newArrayList(iter); > for (Tuple1<String> c : testCentroids) { > System.out.println(c); > } > Output: (Mon Jul 18 17:36:03 CEST 2016) (Mon Jul 18 17:43:58 CEST 2016) > (Mon Jul 18 17:42:59 CEST 2016) (Mon Jul 18 17:34:01 CEST 2016) (Mon Jul 18 > 17:52:00 CEST 2016) (Mon Jul 18 17:40:58 CEST 2016) for centroidId.print(), > but no output for System.out.println(c); Best Regards, Subash Basnet > > On Tue, Jul 19, 2016 at 10:48 AM, subash basnet <yasub...@gmail.com> > wrote: > >> Hello all, >> >> I am trying to convert datastream to collection, but it's shows blank >> result. There is a stream of data which can be viewed on the console on >> print(), but the collection of the same stream shows empty after >> conversion. Below is the code: >> >> DataStream<Centroid> centroids = newCentroidDataStream.map(new >> TupleCentroidConverter()); >> centroids.print(); >> Iterator<Centroid> iter = DataStreamUtils.collect(centroids); >> Collection<Centroid> testCentroids = Lists.newArrayList(iter); >> for(Centroid c: testCentroids){ >> System.out.println(c); >> } >> >> The above *centroids.print()* gives the following output in console: >> >> Mon Jul 18 21:29:01 CEST 2016 119.3701 119.4 119.3701 119.38 27400.0 >> Mon Jul 18 21:23:00 CEST 2016 119.3463 119.37 119.315 119.37 48200.0 >> Mon Jul 18 21:27:59 CEST 2016 119.3401 119.3401 119.26 119.265 50300.0 >> Mon Jul 18 21:36:00 CEST 2016 119.48 119.505 119.47 119.4741 37400.0 >> Mon Jul 18 21:33:00 CEST 2016 119.535 119.54 119.445 119.455 152900.0 >> >> But the next *System.out.println(c) *within the for loop prints nothing. >> What could be the problem. >> >> My maven has following configuration for dataStreamUtils: >> <dependency> >> <groupId>org.apache.flink</groupId> >> <artifactId>flink-streaming-contrib_2.10</artifactId> >> <version>${flink.version}</version> >> </dependency> >> >> >> Best Regards, >> Subash Basnet >> >> >