[LOG4J2-1153] Unable to define only rootLogger in a properties file.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4
• Fix Version/s: 2.4.1
• Component/s: Configurators
• Labels: logger nullpointerexception properties root xml

Environment

Linux Ubuntu 14.04; Java 1.8; Log4j-2.4

• Assignee: Remko Popma
• Reporter: ElMehdi TAHRI
• Created: 06/Oct/15 14:03
• Updated: 06/Oct/15 15:03
• Resolved: 06/Oct/15 14:32

Description

I've changed the version of log4j2 from 2.3 to 2.4 in order to load the configuration via properties file. So i have converted the xml file, that defines only <Root> in <Loggers> element, into a properties file.
This is a preview of the xml file :

  <Loggers>
      <Root level="info">
         <AppenderRef ref="ConsoleAppender"/>
     </Root>
  </Loggers>

And this is a preview of the properties file :

rootLogger.level = info
rootLogger.appenderRefs = console
rootLogger.appenderRef.console.ref = ConsoleAppender

This configuration throw a null pointer exception :

Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException
	at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory.getConfiguration(PropertiesConfigurationFactory.java:132)
	at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory.getConfiguration(PropertiesConfigurationFactory.java:44)
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:491)
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:461)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(ConfigurationFactory.java:257)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:493)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:510)
	at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:199)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:146)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:41)
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:264)
	at org.apache.log4j.Logger$PrivateManager.getContext(Logger.java:59)
	at org.apache.log4j.Logger.getLogger(Logger.java:41)

In order to make this configuration work, i had to add the loggers component and fill the identifiers. My question is why in xml file we can define only a root logger and it works fine, and in a properties file it does not work ?