Simple Logging Facade for Java

 The Simple Logging Facade for Java (or SLF4J) is intended to serve as
 a simple facade for various logging APIs allowing to the end-user to
 plug in the desired implementation at deployment time. SLF4J also
 allows for a gradual migration path away from Apache Commons
 Logging (CL)
 .
 Logging API implementations can either choose to implement the SLF4J
 interfaces directly, e.g. logback or SimpleLogger. Alternatively, it
 is possible (and rather easy) to write SLF4J adapters for the given
 API implementation, e.g. Log4jLoggerAdapter or JDK14LoggerAdapter.