How do you configure Spring Kafka for Avro with Confluent Schema Registry?

Spring does not ship the Avro serializers; they come from Confluent's kafka-avro-serializer library, which you add as a dependency. Spring Boot exposes serializer classes directly and passes any other client setting through the generic properties map (spring.kafka.producer.properties.* and spring.kafka.consumer.properties.*). Producer: spring.kafka.producer.value-serializer=io.confluent.kafka.serializers.KafkaAvroSerializer and spring.kafka.producer.properties.schema.registry.url=http://schema-registry:8081. Consumer: spring.kafka.consumer.value-deserializer=io.confluent.kafka.serializers.KafkaAvroDeserializer, spring.kafka.consumer.properties.schema.registry.url=http://schema-registry:8081 and spring.kafka.consumer.properties.specific.avro.reader=true. specific.avro.reader defaults to false, in which case the consumer returns GenericRecord; true returns your generated classes (SpecificRecord). Generate the Java classes from .avsc files with a build plugin such as avro-maven-plugin. On send, the serializer registers the schema in the registry under a subject such as <topic>-value, and each message carries a magic byte and a schema ID rather than the schema itself.

Expected key concepts: KafkaAvroSerializer, KafkaAvroDeserializer, schema.registry.url, specific.avro.reader, avro-maven-plugin, Confluent, schema ID, spring.kafka.producer.properties, GenericRecord, SpecificRecord, subject