Kafka use demo

till 20fce82112 add missing annotation @Component %!s(int64=4) %!d(string=hai) anos
kafka_server cd7cc5f7b7 First commit %!s(int64=4) %!d(string=hai) anos
src 20fce82112 add missing annotation @Component %!s(int64=4) %!d(string=hai) anos
.gitignore cd7cc5f7b7 First commit %!s(int64=4) %!d(string=hai) anos
pom.xml cd7cc5f7b7 First commit %!s(int64=4) %!d(string=hai) anos