DUE TO SPAM, SIGN-UP IS DISABLED. Goto Selfserve wiki signup and request an account.
This page is meant as a template for writing a KIP. To create a KIP choose Tools->Copy on this page and modify with your content and replace the heading with the next KIP number and a description of your issue. Replace anything in italics with your own description.
Status
Current state: Under Discussion
Discussion thread: https://lists.apache.org/thread/n3k6vb4vddl1s5nopcyglnddtvzp4j63
JIRA: KAFKA-16796
Motivation
We are going to move all tools-related code from core module (scala) to tools module (java) in 4.0. kafka.serializer.Decoder is a public APIs and it is in core module. Hence we need to introduce replacement to deprecate it in 3.8.0
Public Interfaces
The new java interface org.apache.kafka.tools.api.Decoder is shown below. It is located at tools-api module, since it must be accessible by core module.
@FunctionalInterface
public interface Decoder<T> {
T fromBytes(byte[] bytes);
}
The old scala trait will extend the new java interface with deprecated annotation
@deprecated(since = "3.8.0")
trait Decoder[T] {
def fromBytes(bytes: Array[Byte]): T
}
Proposed Changes
- Introduce a new java interface
org.apache.kafka.tools.api.Decoderto replace scala trait kafka.serializer.Decoder - deprecate all "class names" of kafka.serializer.Decoder implementations. That includes
kafka.serializer.DefaultDecoder,kafka.serializer.StringDecoder,kafka.serializer.LongDecoder,kafka.serializer.IntegerDecoder
Compatibility, Deprecation, and Migration Plan
- before 4.0, users can keep using the deprecated kafka.serializer.Decoder
- after 4.0, all users need to update is the superclass is changed from kafka.serializer.Decoder to
org.apache.kafka.tools.api.Decoder. They have same methods, so users don't need to change any code of method implementation - before 4.0, users can access both interfaces by depending on core module.
- after 4.0, users need to import tools-api module if core module is gone
Test Plan
The new unit test used to verify the "warning messages" about deprecated kafka.serializer.Decoder will be added. The messages are used to encourage users to adopt the new interface
Rejected Alternatives
N/A