1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/task4/solution07/src/org/apidesign/apifest08/currency/TimeRangeSpecificConvertor.java	Fri Oct 17 17:33:32 2008 +0200
     1.3 @@ -0,0 +1,109 @@
     1.4 +package org.apidesign.apifest08.currency;
     1.5 +
     1.6 +import java.util.Currency;
     1.7 +import java.util.Date;
     1.8 +import org.apidesign.apifest08.currency.Convertor.ConversionRequest;
     1.9 +import org.apidesign.apifest08.currency.Convertor.ConversionResult;
    1.10 +
    1.11 +/**
    1.12 + * This {@link Convertor} delegates to an underlying one, provided that the request specifies time between from (included) and till (excluded).
    1.13 + * Otherwise it just refuses to convert.
    1.14 + * @author jdvorak
    1.15 + */
    1.16 +public class TimeRangeSpecificConvertor extends DelegatingConvertor {
    1.17 +
    1.18 +    private final Date from;
    1.19 +    private final Date till;
    1.20 +
    1.21 +    /**
    1.22 +     * A new time range specific convertor.
    1.23 +     * @param old the underlying convertor one delegates to
    1.24 +     * @param from the beginning of the time interval
    1.25 +     * @param till the end of the time interval
    1.26 +     * @throws IllegalArgumentException unless from comes before till
    1.27 +     */
    1.28 +    public TimeRangeSpecificConvertor( final Convertor old, final Date from, final Date till ) {
    1.29 +        super( old );
    1.30 +        this.from = from;
    1.31 +        this.till = till;
    1.32 +        if (! from.before( till ) ) {
    1.33 +            throw new IllegalArgumentException( "from must come before till" );
    1.34 +        }
    1.35 +    }
    1.36 +
    1.37 +    /**
    1.38 +     * The beginning of the time interval.
    1.39 +     */
    1.40 +    public Date getFrom() {
    1.41 +        return from;
    1.42 +    }
    1.43 +
    1.44 +    /**
    1.45 +     * The end of the time interval.
    1.46 +     */
    1.47 +    public Date getTill() {
    1.48 +        return till;
    1.49 +    }
    1.50 +
    1.51 +    /**
    1.52 +     * The conversion method.
    1.53 +     * Takes a {@link TimeSpecificConversionRequest}, other {@link ConversionRequest}s will result in an exception being thrown.
    1.54 +     * @param req the request; must not be null; must be {@link TimeSpecificConversionRequest} or a subclass thereof
    1.55 +     * @return the response
    1.56 +     * @throws IllegalRequestSubtypeException iff req is not instance of {@link TimeSpecificConversionRequest}
    1.57 +     */
    1.58 +    @Override
    1.59 +    public ConversionResult convert( final ConversionRequest req ) {
    1.60 +        if ( req instanceof TimeSpecificConversionRequest ) {
    1.61 +            final Date time = ( (TimeSpecificConversionRequest) req ).getTime();
    1.62 +            if ( ( from == null || !from.after(time) ) && ( till == null || time.before(till) ) ) {
    1.63 +                return super.convert( req );
    1.64 +            } else {
    1.65 +                return new ConversionResult( null );
    1.66 +            }
    1.67 +        } else {
    1.68 +            throw new IllegalRequestSubtypeException( this.getClass().getName() + ".convert() requires a TimeSpecificConversionRequest to be passed in" );
    1.69 +        }
    1.70 +    }
    1.71 +
    1.72 +    /**
    1.73 +     * The request for converting a monetary amount into another currency using the conditions that apply at a particular time.
    1.74 +     * Immutable.
    1.75 +     */
    1.76 +    public static class TimeSpecificConversionRequest extends Convertor.ConversionRequest {
    1.77 +
    1.78 +        private final Date time;
    1.79 +
    1.80 +        /**
    1.81 +         * A request to convert srcAmount into tgtCurrency at the current time.
    1.82 +         * @param srcAmount the source amount; must not be null
    1.83 +         * @param tgtCurrency the currency we want it in afterwards; must not be null
    1.84 +         */
    1.85 +        public TimeSpecificConversionRequest( final MonetaryAmount srcAmount, final Currency tgtCurrency ) {
    1.86 +            this( srcAmount, tgtCurrency, new Date() );
    1.87 +        }
    1.88 +
    1.89 +        /**
    1.90 +         * A request to convert srcAmount into tgtCurrency at given time.
    1.91 +         * @param srcAmount the source amount; must not be null
    1.92 +         * @param tgtCurrency the currency we want it in afterwards; must not be null
    1.93 +         * @param time the time instant when the conversion is to be carried out
    1.94 +         */
    1.95 +        public TimeSpecificConversionRequest( final MonetaryAmount srcAmount, final Currency tgtCurrency, final Date time ) {
    1.96 +            super( srcAmount, tgtCurrency );
    1.97 +            this.time = time;
    1.98 +            if ( time == null ) {
    1.99 +                throw new NullPointerException( "The time of conversion" );
   1.100 +            }
   1.101 +        }
   1.102 +
   1.103 +        /**
   1.104 +         * The time as of which the conversion is to be carried out.
   1.105 +         */
   1.106 +        public Date getTime() {
   1.107 +            return time;
   1.108 +        }
   1.109 +
   1.110 +    }
   1.111 +
   1.112 +}