Apache Log4j is a Java-based logging utility originally written by Ceki Gülcü. It is part of the Apache Logging Services, a project of the Apache Software Foundation. Log4j is one of several Java logging frameworks. Gülcü has since created SLF4J, Reload4j,[4] and Logback[5][better source needed] which are alternatives to Log4j.[6] The Apache Log4j team developed Log4j 2[7] in response to the probl