What are the logging frameworks supported by Spring Boot?

There are several logging frameworks supported by Spring Boot.

1. Logback, chosen as the default logging framework for Spring Boot, is the successor to Log4j, offering improved performance and reliability.
2. Log4j2 is an upgraded version of Log4j that offers improved performance and functionality, including support for asynchronous logging and a plugin mechanism.
3. JUL (java.util.logging): JUL is the default logging framework for Java SE. Spring Boot can be configured to use JUL as the logging framework, but it is generally not recommended.
4. SLF4J is a simple logging facade that can be integrated with various logging implementations such as Logback and Log4j2.
5. Commons Logging: Commons Logging is a logging facade provided by Apache that can be integrated with multiple logging implementations.

It is worth noting that Spring Boot supports switching between different logging frameworks through configuration. This can be done in the application.properties or application.yml files. By default, if Logback is found in the classpath, it will be used as the logging framework; otherwise, JUL will be used. The logging framework can be switched by configuring the spring-boot-starter-logging dependency.