Logging in Spring Boot

When using starters, Logback is used for logging by default.

@RestController
public class LoggingController {

    Logger logger = LoggerFactory.getLogger(LoggingController.class);

    @RequestMapping("/")
    public String index() {
        logger.trace("A TRACE Message");
        logger.debug("A DEBUG Message");
        logger.info("An INFO Message");
        logger.warn("A WARN Message");
        logger.error("An ERROR Message");

        return "Howdy! Check out the Logs to see the output...";
    }
}

the default logging level of the Logger is preset to INFO, meaning that TRACE and DEBUG messages are not visible.

References
https://www.baeldung.com/spring-boot-logging