[KAFKA-8296] Kafka Streams branch method raises type warnings

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Component/s: streams
• Assignee: Ivan Ponomarev
• Reporter: Michael Drogalis
• Created: 26/Apr/19 20:08
• Updated: 17/Jul/20 02:20
• Resolved: 17/Jul/20 02:20

Description

Because the branch method in the DSL takes vargargs, using it as follows raises an unchecked type warning:

        KStream<String, User>[] branches = builder.<String, User>stream(inputTopic)
                .branch((key, user) -> "united states".equals(user.getCountry()),
                        (key, user) -> "germany".equals(user.getCountry()),
                        (key, user) -> "mexico".equals(user.getCountry()),
                        (key, user) -> true);

The compiler warns with:

Warning:(39, 24) java: unchecked generic array creation for varargs parameter of type org.apache.kafka.streams.kstream.Predicate<? super java.lang.String,? super io.confluent.developer.avro.User>[]

This is unfortunate because of the way Java's type system + generics work. We could possibly fix this by adding the @SafeVarargs annotation to the branch method signatures.

Issue Links

• is fixed by: KAFKA-5488 KStream.branch should not return a Array of streams we have to access by known index
• is related to: KAFKA-5488 KStream.branch should not return a Array of streams we have to access by known index
• mentioned in: Page Loading...