Spring for Apache Kafka @SpringOnePlatform
This project is used for the demos; it has a number of Spring Boot applications, demonstrating various capabilities of spring-kafka.
Each application is in package org.s1p.appX (where appX is app1, app2, etc).
Common configuration is in the CommonConfiguration class.
The apps require 2 topics to be created in Kafka...
kafka-topics --zookeeper localhost:2181 --create --topic s1p.topic --partitions 5 --replication-factor 1
kafka-topics --zookeeper localhost:2181 --create --topic s1p.fooTopic --partitions 5 --replication-factor 1
The first four apps use String serializers and deserializers for both the key and value.
This is the first app which simply sends a message to the s1p.topic.
This adds a simple @KafkaListener to receive messages from s1p.topic in a POJO method.
This shows how to access the partition from which the message was received in a @KafkaListener POJO method.
This shows a @KafkaListener where the topics/partitions are explicitly subscribed to, together with an initial offset.
This introduces JSON serializer and deserializer for the value.
It uses JsonConfiguration instead of CommonConfiguration; note that the type (Foo) is hard-coded into the deserializer - this is required since the JSON contains no type information.
This is a more flexible alternative to using the Json serializer and deserializer.
Instead, it uses StringJsonMessageConverter s and reverts to using String serializer/deserializer.
One benefit of this technique is the type used in the conversion is inferred from the method argument type.
Notice that we send a Foo and receive a Bar - of course, the types need to have compatible fields.
This builds on app2 by adding retry and filtering to the listener.
This version of app2 uses the lower-level KafkaMessageListenerContainer instead of a @KafkaListener.
This version of app8 commits the offsets manually.
