[KAFKA-12883] Adress KIP-100 type constraints now that Java 7 support is dropped

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: streams
• Labels: StarterProject newbie++
• Assignee: Nicolas Guignard
• Reporter: Xavier Léauté
• Created: 03/Jun/21 02:46
• Updated: 17/Jun/21 01:06

Description

As part of KIP-100 rejected alternatives, we suggested a more correct alternative to the type constraints for some of the KStream methods.

Unfortunately at the time, there was a Java 7 compiler behavior that prevented us from using those type constraints, so we had to relax them in order to preserve backwards compatibility.

As part of the KIP it was mentioned that:

Once we drop support for 1.7 we can always decide to switch to approach 2. without breaking source compatibility, by making a proposal similar to this KIP.

Since Java 7 support has been dropped a while ago, it would be a good time to revisit this and possibly switch to the alternative type constraints. The change should be source compatible, although the streams APIs have significantly evolved since, so there might be some additional investigation required to ensure that is still the case and also covers the Scala Streams APIs.