public String getString(String key, String defaultValue) {
        return this.props.getValueOrDefault(key, defaultValue);
    }
public String getString ( String key , String defaultValue ) { return this . props . getValueOrDefault ( key , defaultValue ) ; }
Retrieves a configuration value with the given key

@param key The key of the configuration value (e.g. application.name)
@param defaultValue The default value to return of no key is found
@return The configured value as String or the passed defautlValue if the key is not configured