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
