# Spring Boot Logging
- Commons Logging interface
- Java Util Logging, Log4J2, Logback.
- Log Level: ERROR, WARN, INFO, DEBUG, TRACE

## File Output
- `logging.file.name` or `logging.file.path` property
- 10 MB rotate

## ref
- https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-logging
- https://www.baeldung.com/spring-boot-logging