Simple Logging Facade for Java (abbreviated SLF4J)

• acts as a facade for different logging frameworks (e.g. java.util.logging, logback, Log4j)
• offers a generic API making the logging independent of the actual implementation

1 - Writing Log Messages

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
public class MyClass { 
    Logger log = LoggerFactory.getLogger(this.getClass().getName());
 
    public void myMethod() {
		log.debug("This is a DEBUG message");
        log.info("This is an INFO message");
		log.warning("This is a WARNING message");
		log.error("This is an ERROR message");
		log.fatal("This is a FATAL message");
    } 
}

or use Lombok’s @Slf4j

@Slf4j
public class MyClass { 
 
    public void myMethod() {
  		log.debug("This is a DEBUG message");
        log.info("This is an INFO message");
		log.warning("This is a WARNING message");
		log.error("This is an ERROR message");
		log.fatal("This is a FATAL message"); 
     } 
}

2 - Subpages

• Slf4j - Extended Logger ／ XLogger

3 - Resources

• https://www.baeldung.com/slf4j-with-log4j2-logback