Please read the javadoc: https://github.com/apache/kafka/blob/trunk/streams/src/main/java/org/apache/kafka/streams/Consumed.java
and correlate with the sample code. Thanks On Sat, Feb 10, 2018 at 1:10 PM, Debasish Ghosh <ghosh.debas...@gmail.com> wrote: > Looking at > https://github.com/confluentinc/kafka-streams- > examples/blob/3.3.x/src/test/scala/io/confluent/examples/streams/ > StreamToTableJoinScalaIntegrationTest.scala#L148, > it seems that the leftJoin generates a KStream[String, (String, Long)], > which means the value is a tuple of (String, Long) .. I am not able to get > how this will serialize/de-serialize with the default serializers which are > both stringSerde for keys and values. > > or am I missing something ? > > regards. > > On Sun, Feb 11, 2018 at 2:30 AM, Ted Yu <yuzhih...@gmail.com> wrote: > > > If I read the code correctly, the operation on this line prepares the > input > > for the (stringSerde, stringSerde) specified on line 142: > > > > .leftJoin(userRegionsTable, (clicks: Long, region: String) => (if > > (region == null) "UNKNOWN" else region, clicks)) > > > > FYI > > > > On Sat, Feb 10, 2018 at 11:00 AM, Debasish Ghosh < > ghosh.debas...@gmail.com > > > > > wrote: > > > > > Hi - > > > > > > I was going through this example at > > > https://github.com/confluentinc/kafka-streams- > > > examples/blob/3.3.x/src/test/scala/io/confluent/examples/streams/ > > > StreamToTableJoinScalaIntegrationTest.scala, > > > especially the leftJoin part > > > https://github.com/confluentinc/kafka-streams- > > > examples/blob/3.3.x/src/test/scala/io/confluent/examples/streams/ > > > StreamToTableJoinScalaIntegrationTest.scala#L156. > > > This leftJoin returns KStream[String, (String, Long)], while default > > > serializers are String for both key and value as in > > > https://github.com/confluentinc/kafka-streams- > > > examples/blob/3.3.x/src/test/scala/io/confluent/examples/streams/ > > > StreamToTableJoinScalaIntegrationTest.scala#L112-L113. > > > My question is how does this serialization work here ? I mean how does > > the > > > tuple get serialized with the default serializers ? And leftJoin only > > works > > > with default serializers .. > > > > > > regards. > > > > > > -- > > > Debasish Ghosh > > > http://manning.com/ghosh2 > > > http://manning.com/ghosh > > > > > > Twttr: @debasishg > > > Blog: http://debasishg.blogspot.com > > > Code: http://github.com/debasishg > > > > > > > > > -- > Debasish Ghosh > http://manning.com/ghosh2 > http://manning.com/ghosh > > Twttr: @debasishg > Blog: http://debasishg.blogspot.com > Code: http://github.com/debasishg >
