From my prespective, Apache Kafka is good for java programming, build server for mini API to the kafka topics and build any microservices from other language programming.
But, in order to build program with java, at least you must understand several packages from maven/spring java.
This is sample Application for kafka java stream insert from WikimediaDataChanges to Mysql
- Producer Wikimedia
- Consumer Wikimedia to Database
Producer Wikimedia using an Url for stream changes happen in Wikipedia, and each Row publish to topics "wikimedia_recentchange". The stream from wikimedia API is applied using EventSource with timeout of 10 ms.
Consumer is listen to topics "wikimedia_recentchange" then make data from the string and save to database MySQL.