1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/task4/solution04/src/org/apidesign/apifest08/currency/Convertor.java	Sat Oct 11 23:38:46 2008 +0200
     1.3 @@ -0,0 +1,59 @@
     1.4 +package org.apidesign.apifest08.currency;
     1.5 +
     1.6 +
     1.7 +import java.math.BigDecimal;
     1.8 +import java.util.Currency;
     1.9 +import java.util.Set;
    1.10 +
    1.11 +
    1.12 +/**
    1.13 + * Convert between two currencies.
    1.14 + *
    1.15 + * @author D'Arcy Smith
    1.16 + * @version 1.0
    1.17 + */
    1.18 +public interface Convertor
    1.19 +{
    1.20 +    /**
    1.21 +     * Convert an amount from one currency to another.
    1.22 +     * 
    1.23 +     * @param from the currency to convert from.
    1.24 +     * @param to the currency to convert to.
    1.25 +     * @param amount the amount to convert.
    1.26 +     * @return the converted amount.
    1.27 +     * @throws IllegalArgumentException if any of the arguments are null.
    1.28 +     * @throws InvalidConversionException if either from or to are not valid for the convertor.
    1.29 +     */
    1.30 +    BigDecimal convert(Currency   from, 
    1.31 +                       Currency   to, 
    1.32 +                       BigDecimal amount)
    1.33 +        throws InvalidConversionException;
    1.34 +
    1.35 +    /**
    1.36 +     * Check to see if converting between the two currencies is possible.
    1.37 +     *
    1.38 +     * @param from the currency to convert from.
    1.39 +     * @param to the currency to convert to.
    1.40 +     * @return true if the conversion is possible.
    1.41 +     */
    1.42 +    boolean canConvert(Currency from, Currency to);
    1.43 +
    1.44 +    /**
    1.45 +     * Get the currencies that the convertor supports.  Just because a currency is
    1.46 +     * supported does not mean that canConvert will return true.
    1.47 +     * 
    1.48 +     * @return the supported currencies.
    1.49 +     */
    1.50 +    Set<Currency> getCurrencies();
    1.51 +
    1.52 +    /**
    1.53 +     * Get the conversion rate between two currencies.
    1.54 +     * 
    1.55 +     * @param from the currency to convert from.
    1.56 +     * @param to the currency to convert to.
    1.57 +     * @return the conversion rate between the two currencies.
    1.58 +     * @throws InvalidConversionException if canConvert would return false.
    1.59 +     */
    1.60 +    BigDecimal getConversionRate(final Currency from, final Currency to)
    1.61 +        throws InvalidConversionException;
    1.62 +}