code: public String getFormattedMessage(String messageKey, Object[] param, String defaultKey) {
  		String key = getString(messageKey);
  		String retVal = MessageFormat.format(key, param);
  		return retVal;
  	}
docs: Retrieve a message and format it with the parameters
  
  @param messageKey
  Message key to use
  @param param
  Object to use for formatting
  @param defaultKey
  The default key to use in case message key is not found
  @return message formatted with the parameters