No log4j2 configuration file found. Using default configuration: logging only errors to the console

Question

$ java -Dlog4j.configuration=file:///path/to/your/log4j2.xml -jar /path/to/your/jar_file.jar

Written to the console, you get

ERROR          


        

Answer 1

This sometimes can be thrown before the actual log4j2 configuration file found on the web servlet. at least for my case I think so. Cuz I already have in my web.xml

  
    log4jConfiguration
    classpath:log4j2-app.xml
  

and checking the log4j-web source; in class

org.apache.logging.log4j.web.Log4jWebInitializerImpl

there is the line;

String location = this.substitutor
                 .replace(this.servletContext.getInitParameter("log4jConfiguration"));

all those makes me think that this is temporary log before configuration found.