$ brew install kafka
$ zookeeper-server-start /usr/local/etc/kafka/zookeeper.properties
$ kafka-server-start /usr/local/etc/kafka/server.properties
$ kafka-topics --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic Kafka-Demo
kafka-console-consumer --bootstrap-server localhost:9092 --topic Kafka-Demo --from-beginning
mvn spring-boot:run