package org.apidesign.apifest08.currency;

/**

 * Convertor factory is a factory class for creating {@link Convertor Convertor}

 * instances.

 *

 * @author jindra

 */

public final class ConvertorFactory {

    // this class needs no instances

    private ConvertorFactory() {

    }

    /**

     * Create a {@link Convertor Convertor} with given exchange rate

     *

     * @param exchangeRate double reprezenting the exchange rate from primary currency into

     * the secundary currecny

     * @return {@link Convertor Convertor} instance with given exchange rate

     */

    public static Convertor createConvertor(double exchangeRate) {

        if (exchangeRate == 0) {

            throw new IllegalArgumentException("Zero exchange rate is not allowed.");

        }

        return new ConvertorImpl(exchangeRate);

    }

}