* Initialize the logging system according to preferences expressed through the
* {@link Environment} and the classpath.
*/
protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) {
if (System.getProperty("PID") == null) {
System.setProperty("PID", new ApplicationPid().toString());
}
initializeEarlyLoggingLevel(environment);
LoggingSystem system = LoggingSystem.get(classLoader);
initializeSystem(environment, system);
initializeFinalLoggingLevels(environment, system);