apollo-common/src/main/java/com/ctrip/framework/apollo/common/controller/GlobalDefaultExceptionHandler.java/GlobalDefaultExceptionHandler/printLog
class GlobalDefaultExceptionHandler:  private void printLog(String message, Throwable ex, Level logLevel) {
    switch (logLevel) {
      case ERROR:
        logger.error(message, ex);
        break;
      case WARN:
        logger.warn(message, ex);
        break;
      case DEBUG:
        logger.debug(message, ex);
        break;
      case INFO:
        logger.info(message, ex);
        break;
      case TRACE:
        logger.trace(message, ex);
        break;
    }

    Tracer.logError(ex);
  }