26. Logging

Spring Boot uses Commons Logging for all internal logging, but leaves the underlying log implementation open. Default configurations are provided for Java Util Logging, Log4J2 and Logback. In each case loggers are pre-configured to use console output with optional file output also available.

By default, If you use the ‘Starters’, Logback will be used for logging. Appropriate Logback routing is also included to ensure that dependent libraries that use Java Util Logging, Commons Logging, Log4J or SLF4J will all work correctly.

	Tip
There are a lot of logging frameworks available for Java. Don’t worry if the above list seems confusing. Generally you won’t need to change your logging dependencies and the Spring Boot defaults will work just fine.