https://medium.com/@conqueror89107/spring-boot-%E6%89%8B%E6%8A%8A%E6%89%8B-%E7%9B%B4%E5%88%B0%E4%BD%A0%E6%93%81%E6%9C%89-03-%E5%AF%A6%E6%88%B0-rsetful-%E9%A2%A8%E6%A0%BC-api-ch3-2-7f4e47f09342