public double getDoubleProperty(String key) {
		String value = getProperty(key);
		if (value == null) {
			return 0.0;
		}
		
		try {
			return Double.parseDouble(value);
		} catch (NumberFormatException e) {
			this.logger.logError(LOGGING_SOURCE, "unable to read property value " + key + " as double");
			return 0;
		}
	}