Kafka Streams: Converting KStream to KTable

There are no methods in KStream to convert into a KTable. But there are workarounds to do that. They are as follows:

Write on a Kafka Topic and read back as Kable

We can also write to an intermediate Kafka Topic and read it back using StreamBuilder. Here is an example:

Perform a dummy aggregation

Here is an example we are converting a KStream to KTable using reduce method of KGroupedStream.

Please make sure to use specified Serde (s) for your key and value. I kept getting the following exception until I specified the exact Serde (s)

Ref: These techniques are actually discussed on Confluent.io blog. You can read in details here:

https://docs.confluent.io/current/streams/faq.html#how-can-i-convert-a-kstream-to-a-ktable-without-an-aggregation-step