Starting and Stopping a Kafka Listener after Spring Boot Startup

This example is a fork of the official example.

Start Zookeeper and Kafka from the Kafka directory:

.\bin\windows\zookeeper-server-start.bat .\config\zookeeper.properties
.\bin\windows\kafka-server-start.bat .\config\server.properties

Two topics need to be present:

1. topic1 - expects JSON with a key of foo, so {"foo": "bar"}
2. topic1.DLST - expects a string like "foo" - is listening on startup

.\bin\windows\kafka-topics.bat --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic topic1
.\bin\windows\kafka-topics.bat --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic topic1.DLT

Run the Spring boot application which starts on localhost:8080.

• topic1 listener has not started as @KafkaListener(autoStartup="false")
• topic1.DLT listener has not started as @KafkaListener()'s autoStartup value is "true" by default

Create a producer from the command line and send a few JSON object to topic1 (which is currently off) and send some messages:

PS C:\Users\zarar\Tools\kafka_2.13-2.4.1> .\bin\windows\kafka-console-producer.bat --broker-list localhost:9092 --topic topic1
>{"foo": "bar1"}
>{"foo": "bar2"}
>{"foo": "bar3"}

Now start the @KafkaListener for topic1 by visiting/CURLing:

http://localhost:8080/start

In the Spring Boot terminal you'll see:

2020-04-04 02:49:54.972  INFO 19072 --- [ fooGroup-0-C-1] com.example.Application                  : Received: Foo2 [foo=bar1]
2020-04-04 02:49:54.972  INFO 19072 --- [ fooGroup-0-C-1] com.example.Application                  : Received: Foo2 [foo=bar2]
2020-04-04 02:49:54.972  INFO 19072 --- [ fooGroup-0-C-1] com.example.Application                  : Received: Foo2 [foo=bar3]

To stop listening:

http://localhost:8080/stop