code: protected static void initLogger ()
      {
          // if a custom class was specified as a system property, use that
          Factory factory = createConfiguredFactory();
  
          // create and a log4j logger if the log4j configuration system property is set
          try {
              if (factory == null && System.getProperty("log4j.configuration") != null) {
                  factory = (Factory)Class.forName("com.samskivert.util.Log4JLogger").newInstance();
              }
          } catch (SecurityException se) {
              // in a sandbox, no biggie
          } catch (Throwable t) {
              System.err.println("Unable to instantiate Log4JLogger: " + t);
          }
  
          // create and a log4j2 logger if the log4j2 configuration system property is set
          try {
              if (factory == null && System.getProperty("log4j.configurationFile") != null) {
                  factory = (Factory)Class.forName("com.samskivert.util.Log4J2Logger").newInstance();
              }
          } catch (SecurityException se) {
              // in a sandbox, no biggie
          } catch (Throwable t) {
              System.err.println("Unable to instantiate Log4J2Logger: " + t);
          }
  
          // lastly, fall back to the Java logging system
          if (factory == null) {
              factory = new JDK14Logger();
          }
  
          // and finally configure our factory
          setFactory(factory);
      }
docs: Called at static initialization time. Selects and initializes our logging backend.