1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/task4/solution02/src/org/apidesign/apifest08/currency/DefaultConvertor.java	Sat Oct 11 23:38:46 2008 +0200
     1.3 @@ -0,0 +1,95 @@
     1.4 +package org.apidesign.apifest08.currency;
     1.5 +
     1.6 +import java.io.Serializable;
     1.7 +import java.math.BigDecimal;
     1.8 +import java.math.RoundingMode;
     1.9 +import java.util.Currency;
    1.10 +
    1.11 +/**
    1.12 + * Default {@link Convertor} implementation. Exchange rate is stored as equivalents. It means if we have USD to CZK convertor and USD1 = CZK17 
    1.13 + * we store 1 in sourceEquivalent and 17 in destinationEquivalent. This class is immutable.
    1.14 + * @author lukas
    1.15 + *
    1.16 + */
    1.17 +class DefaultConvertor implements ExtendedConvertor, Serializable {
    1.18 +
    1.19 +	private static final long serialVersionUID = 6660014633685135034L;
    1.20 +
    1.21 +	/**
    1.22 +	 * Equivalent in source currency.
    1.23 +	 */
    1.24 +	private final BigDecimal sourceEquivalent;
    1.25 +	
    1.26 +	/**
    1.27 +	 * Equivalent in destination currency.
    1.28 +	 */
    1.29 +	private final BigDecimal destinationEquivalent;
    1.30 +	
    1.31 +	private final Currency sourceCurrency;
    1.32 +	
    1.33 +	private final Currency destinationCurrency;
    1.34 +	
    1.35 +	public DefaultConvertor(Money sourceEquivalent, Money destinationEquivalent) {
    1.36 +		super();
    1.37 +		if (BigDecimal.ZERO.compareTo(sourceEquivalent.getAmount())==0)
    1.38 +		{
    1.39 +			throw new IllegalArgumentException("Source equivalent amount can not be 0.");
    1.40 +		}
    1.41 +		if (BigDecimal.ZERO.compareTo(destinationEquivalent.getAmount())==0)
    1.42 +		{
    1.43 +			throw new IllegalArgumentException("Destination equivalent amount can not be 0.");
    1.44 +		}
    1.45 +		this.sourceEquivalent = sourceEquivalent.getAmount();
    1.46 +		this.destinationEquivalent = destinationEquivalent.getAmount();
    1.47 +		this.sourceCurrency = sourceEquivalent.getCurrency();
    1.48 +		this.destinationCurrency = destinationEquivalent.getCurrency();
    1.49 +	}
    1.50 +	
    1.51 +	public Money convert(Money amount, Currency destinationCurrency) {
    1.52 +		if (amount==null)
    1.53 +		{
    1.54 +			throw new NullPointerException("Money is null");
    1.55 +		}
    1.56 +		if (destinationCurrency==null)
    1.57 +		{
    1.58 +			throw new NullPointerException("destionationCurrency is null");
    1.59 +		}
    1.60 +		if (!amount.getCurrency().equals(getSourceCurrency()))
    1.61 +		{
    1.62 +			throw new IllegalArgumentException("Can not convert from "+amount.getCurrency()+". Converts between "+getSourceCurrency()+" and "+getDestinationCurrency());
    1.63 +		}
    1.64 +		if (!getDestinationCurrency().equals(destinationCurrency))
    1.65 +		{
    1.66 +			throw new IllegalArgumentException("Can not convert to "+destinationCurrency+". Converts between "+getSourceCurrency()+" and "+getDestinationCurrency());
    1.67 +		}
    1.68 +		BigDecimal sourceAmount = amount.getAmount();
    1.69 +		BigDecimal destinationAmount = sourceAmount.multiply(destinationEquivalent).divide(sourceEquivalent, 2, RoundingMode.HALF_UP);
    1.70 +		return new MoneyImpl(destinationAmount, getDestinationCurrency());
    1.71 +	}
    1.72 +	
    1.73 +	public boolean isConversionSupported(Currency from, Currency to) {
    1.74 +		return sourceCurrency.equals(from) && destinationCurrency.equals(to);
    1.75 +	}
    1.76 +
    1.77 +	public BigDecimal getSourceEquivalent() {
    1.78 +		return sourceEquivalent;
    1.79 +	}
    1.80 +
    1.81 +	public BigDecimal getDestinationEquivalent() {
    1.82 +		return destinationEquivalent;
    1.83 +	}
    1.84 +
    1.85 +	public Currency getSourceCurrency() {
    1.86 +		return sourceCurrency;
    1.87 +	}
    1.88 +
    1.89 +	public Currency getDestinationCurrency() {
    1.90 +		return destinationCurrency;
    1.91 +	}
    1.92 +	
    1.93 +	@Override
    1.94 +	public String toString() {
    1.95 +		return getClass().getName()+" converts "+getSourceCurrency()+" to "+getDestinationCurrency()+" "
    1.96 +			+getSourceCurrency()+getSourceEquivalent()+"="+getDestinationCurrency()+getDestinationEquivalent();
    1.97 +	}
    1.98 +}