Slf4j with log4j2 Example.

What is slf4j :- The Simple Logging Facade for Java (SLF4J) serves as a simple facade or abstraction for various logging frameworks (e.g. java.util.logging, logback, log4j) allowing the end user to plug in the desired logging framework at deployment time.Here we are using log4j2 logging framework at deployment time for this we need to add below jars.

Now create java class with slf4j logger object.

Test.java

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class Test {

private static final Logger logger = LoggerFactory.getLogger(Test.class);

public static void main(String[] args) {

               logger.debug("this is debug msg");

               logger.info("this is info mesg");

      

}

}

Now where we have to store logs and which pattern we have to print logs these are all configure in log4j2.xml

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>

<Configuration>

  <Appenders>

    <Console name="STDOUT" target="SYSTEM_OUT">

        <PatternLayout pattern="current date-%d LEVEL-%-5p  Thread-[%t]  Method-%M()   Class name-%C   Message-%m%n"/>

    </Console>

  </Appenders>

   <loggers>

  <Logger name="org.apache.log4j.xml" level="all"/>

    <root level="all">

      <appender-ref ref="STDOUT"/>

    </root>

  </loggers>

</Configuration>

Note: the configuration file log4j2.xml put in class path means under src folder.