anchor.diff:  ----
   Now, the slf4j can find the implmenetaion "org.slf4j.impl.StaticLoggerBinder" in log4j-slf4j-impl, which in turns use log4j-core.
   
  +== Step 4. Add the logger configuration file log4j2.xml into the root of the classpath.
  +
  +log4j2.xml
  +[source,xml]
  +----
  +<?xml version="1.0" encoding="UTF-8"?>
  +<Configuration status="WARN" monitorInterval="30">
  +
  +	<!-- Appenders -->
  +    <Appenders>
  +        <Console name="console" target="System_out">
  +            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
  +        </Console>
  +        <File name="file" fileName="${sys:catalina.base}/log.log" append="false">
  +            <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
  +        </File>
  +        <RollingFile name="rollingFile" fileName="${sys:catalina.base}/logs/app.log"
  +                     filePattern="log/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
  +            <PatternLayout pattern="%d{yyyy-MM-dd 'at' HH:mm:ss z} %-5level %class{36} %L %M - %msg%xEx%n"/>
  +            <SizeBasedTriggeringPolicy size="50MB"/>
  +            <DefaultRolloverStrategy max="20"/>
  +        </RollingFile>
  +    </Appenders>
  +	
  +	<!-- Application Loggers -->
  +    <Loggers>
  +        <Logger name="spittr" level="INFO" />
  +        <Root level="DEBUG">
  +            <AppenderRef ref="console" />
  +            <AppenderRef ref="file" />
  +            <AppenderRef ref="rollingFile" />
  +        </Root>
  +    </Loggers>
  +	
  +</Configuration>
  +----
   
   
  -
  
positive.code: 
  Official Reference: https://docs.spring.io/spring/docs/current/spring-framework-reference/html/overview.html#overview-logging
  
  Step 1. First, tell dependency manager not to use Jakarta Commons Logging (JCL) by adding:
  
  .build.gradle
  [source,groovy]
  
negative.code: 
  Now, Spring can resolve the dependency but that slf4j implementation of JCL's api is actually an API itself. So we need to place the implementation into the classpath.
  
  == Step 3. Add the log4j and log4j-slf4j bridge into the project.
  
  build.gradle
  [source,groovy]
  