- 스프링 부트 스레드
https://velog.io/@sihyung92/how-does-springboot-handle-multiple-requests,
https://velog.io/@gnoesnooj/SPRING-%ED%95%98%EB%82%98%EC%9D%98-%EC%BB%A8%ED%8A%B8%EB%A1%A4%EB%9F%AC%EA%B0%80-%EC%96%B4%EB%96%BB%EA%B2%8C-%EC%88%98%EB%A7%8E%EC%9D%80-request%EB%A5%BC-%EC%B2%98%EB%A6%AC%ED%95%A0-%EC%88%98-%EC%9E%88%EC%9D%84%EA%B9%8C - 상태를 가지는 객체란?
https://imiyoungman.tistory.com/1
