code: static Integer getInteger(Properties properties, String key, Integer defaultValue) {
  		if (properties == null)
  			return defaultValue;
  		String value = properties.getProperty(key);
  		if (value == null || value.isEmpty())
  			return defaultValue;
  		int intVal;
  		try {
  			intVal = Integer.parseInt(value);
  		} catch (NumberFormatException e) {
  			logger.warn("Cannot read property '" + key + "'. Expected integer, but got '" + value + "'. Setting default value = '" + defaultValue + "'", e.getMessage());
  			return defaultValue;
  		}
  		logger.trace("Read property '" + key + "' value '" + intVal + "'");
  		return intVal;
  	}
docs: returns int value of property or defaultValue if not found or invalid