package org.apidesign.apifest08.currency;

 /**

  * Some Factory for Factories :-)

  * Depends on the whole application design...

  * @author Ladislav Vitasek

  */

 final public class ConvertorsFactory {

     private CurrencyConvertorFactory currencyConvertorFactoryInstance = null;

     private final static ConvertorsFactory instance = new ConvertorsFactory();

     private ConvertorsFactory() {

     }

     public static CurrencyConvertorFactory getCurrencyConvertorFactoryInstance() throws CannotInstantiateFactoryException {

         return getInstance().getCurrencyConvertor();

     }

     /**

      * Returns instance of CurrencyConvertorFactory 

      * @return new instance of CurrencyConvertorFactory

      * @throws CannotInstantiateFactoryException

      */

     private synchronized CurrencyConvertorFactory getCurrencyConvertor() throws CannotInstantiateFactoryException {

         if (currencyConvertorFactoryInstance == null) {//intern implementation

 //            String className = System.getProperty("currencyFactory", CurrencyConvertorFactoryImpl.class.getName());

 //            try {

 //                currencyConvertorFactoryInstance = (CurrencyConvertorFactory) Class.forName(className).newInstance();

 //            } catch (Exception e) {

 //                throw new CannotInstantiateFactoryException(e);

 //            }

             //without reflection

             currencyConvertorFactoryInstance = new CurrencyConvertorFactoryImpl();

         }

         return currencyConvertorFactoryInstance;

     }

     public static ConvertorsFactory getInstance() {

         return instance;

     }

 }