Hello,
Starting a discussion for KIP-466 adding support for List Serde. PR is created
under https://github.com/apache/kafka/pull/6592
<https://github.com/apache/kafka/pull/6592>
There are two topics I would like to discuss:
1. Since type for List serve needs to be declared before hand, I could not
create a static method for List Serde under
org.apache.kafka.common.serialization.Serdes. I addressed it in the KIP:
P.S. Static method corresponding to ListSerde under
org.apache.kafka.common.serialization.Serdes (something like static public
Serde<List<T>> List() {...} inorg.apache.kafka.common.serialization.Serdes)
class cannot be added because type needs to be defined beforehand. That's why
one needs to create List Serde in the following fashion:
new Serdes.ListSerde<String>(Serdes.String(),
Comparator.comparing(String::length));
(can possibly be simplified by declaring import static
org.apache.kafka.common.serialization.Serdes.ListSerde)
2. @miguno Michael G. Noll <https://github.com/miguno> is questioning whether I
need to pass a comparator to ListDeserializer. This certainly is not required.
Feel free to add your input:
https://github.com/apache/kafka/pull/6592#discussion_r281152067
Thank you!
Best,
Daniyar Yeralin
> On May 6, 2019, at 11:59 AM, Daniyar Yeralin (JIRA) <[email protected]> wrote:
>
> Daniyar Yeralin created KAFKA-8326:
> --------------------------------------
>
> Summary: Add List<T> Serde
> Key: KAFKA-8326
> URL: https://issues.apache.org/jira/browse/KAFKA-8326
> Project: Kafka
> Issue Type: Improvement
> Components: clients, streams
> Reporter: Daniyar Yeralin
>
>
> I propose adding serializers and deserializers for the java.util.List class.
>
> I have many use cases where I want to set the key of a Kafka message to be a
> UUID. Currently, I need to turn UUIDs into strings or byte arrays and use
> their associated Serdes, but it would be more convenient to serialize and
> deserialize UUIDs directly.
>
> I believe there are many use cases where one would want to have a List serde.
> Ex.
> [https://stackoverflow.com/questions/41427174/aggregate-java-objects-in-a-list-with-kafka-streams-dsl-windows],
>
> [https://stackoverflow.com/questions/46365884/issue-with-arraylist-serde-in-kafka-streams-api]
>
>
>
> KIP Link:
> [https://cwiki.apache.org/confluence/display/KAFKA/KIP-466%3A+Add+support+for+List%3CT%3E+serialization+and+deserialization]
>
>
>
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