Web server failed to start. Port 8080 was already in use

에러 내용

Web server failed to start. Port 3000 was already in use.
Action:
Identify and stop the process that's listening on port 3000 or configure this application to listen on another port.
2019-11-06 22:00:06.094  INFO 8996 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'

에러 원인

포트가 이미 실행 중일 때 스프링을 실행하면 발생하는 에러

해결 방법

실행중인 포트 끊어주기

lsof -i tcp:8080

나온 PID 확인 후

sudo kill -9 {PID 번호}