Hi, You don't need to set the serde until you do another operation that requires serialization, i.e., if you followed the join with a `to()`, `groupBy()` etc, you would pass in the serde to that operation.
Thanks, Damian On Thu, 16 Nov 2017 at 10:53 sy.pan <shengyi....@gmail.com> wrote: > Hi, all: > > Recently I have read kafka streams join document( > https://docs.confluent.io/current/streams/developer-guide.html#kafka-streams-dsl > < > https://docs.confluent.io/current/streams/developer-guide.html#kafka-streams-dsl>). > The sample code is pasted below: > > import java.util.concurrent.TimeUnit; > KStream<String, Long> left = ...; > KStream<String, Double> right = ...; > // Java 7 example > KStream<String, String> joined = left.join(right, > new ValueJoiner<Long, Double, String>() { > @Override > public String apply(Long leftValue, Double rightValue) { > return "left=" + leftValue + ", right=" + rightValue; > } > }, > JoinWindows.of(TimeUnit.MINUTES.toMillis(5)), > Serdes.String(), /* key */ > Serdes.Long(), /* left value */ > Serdes.Double() /* right value */ > ); > > so the question is : > > 1) which parameter is used for setting result value(returned by > ValueJoiner) Serdes class ? > the sample code only set key , left value and right value Serdes class. > > 2) if ValueJoiner return customer value type, how to set the result value > Serdes class ? > > > >
