1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/task4/solution07/test/org/apidesign/apifest08/test/Task3Test.java Sat Oct 11 23:38:46 2008 +0200
1.3 @@ -0,0 +1,135 @@
1.4 +package org.apidesign.apifest08.test;
1.5 +
1.6 +import java.math.BigDecimal;
1.7 +import java.util.Currency;
1.8 +import junit.framework.TestCase;
1.9 +import org.apidesign.apifest08.currency.Convertor;
1.10 +import org.apidesign.apifest08.currency.MonetaryAmount;
1.11 +import org.apidesign.apifest08.currency.anothervendor.ZigZaggingBidirectionalConvertor;
1.12 +
1.13 +/** The exchange rates are not always the same. They are changing. Day by day,
1.14 + * hour by hour, minute by minute. For every bank it is important to always
1.15 + * have the actual exchange rate available in the system. That is why let's
1.16 + * create a pluggable convertor that will always have up to date value of its
1.17 + * exchange rate.
1.18 + * <p>
1.19 + * The quest for today is to allow 3rd party developer to write a convertor
1.20 + * that adjusts its exchange rate everytime it is queried. This convertor is
1.21 + * written by independent vendor, the vendor knows only your Convertor API,
1.22 + * he does not know how the whole system looks and how the convertor is supposed
1.23 + * to be used.
1.24 + */
1.25 +public class Task3Test extends TestCase {
1.26 + public Task3Test(String testName) {
1.27 + super(testName);
1.28 + }
1.29 +
1.30 + @Override
1.31 + protected void setUp() throws Exception {
1.32 + }
1.33 +
1.34 + @Override
1.35 + protected void tearDown() throws Exception {
1.36 + }
1.37 +
1.38 + protected static final Currency CZK = Currency.getInstance( "CZK" );
1.39 + protected static final Currency SKK = Currency.getInstance( "SKK" );
1.40 + protected static final Currency USD = Currency.getInstance( "USD" );
1.41 +
1.42 + // Backward compatibly enhance your existing API to support following
1.43 + // usecases:
1.44 + //
1.45 +
1.46 +
1.47 + /** Without knowing anything about the surrounding system, write an
1.48 + * implementation of convertor that will return different rates everytime
1.49 + * it is queried. Convert USD to CZK and vice versa. Start with the rate of
1.50 + * 1USD = 16CZK and adjust it in favor of CZK by 0.01 CZK with every query.
1.51 + * As soon as you reach 1USD = 15CZK adjust it by 0.01 CZK in favor of USD
1.52 + * until you reach 1USD = 16CZK
1.53 + *
1.54 + * @return new instance of "online" USD and CZK convertor starting with rate 1USD = 16CZK
1.55 + */
1.56 + public static Convertor createOnlineCZKUSDConvertor() {
1.57 + // initial rate: 1USD = 16CZK
1.58 + // 2nd query 1USD = 15.99CZK
1.59 + // 3rd query 1USD = 15.98CZK
1.60 + // until 1USD = 15.00CZK
1.61 + // then 1USD = 15.01CZK
1.62 + // then 1USD = 15.02CZK
1.63 + // and so on and on up to 1USD = 16CZK
1.64 + // and then another round to 15, etc.
1.65 + final MonetaryAmount oneUSD = new MonetaryAmount( 1, USD );
1.66 + final BigDecimal startAmount = new BigDecimal( 16 );
1.67 + final BigDecimal endAmount = new BigDecimal( 15 );
1.68 + final BigDecimal stepAmount = BigDecimal.ONE.movePointLeft( 2 ).negate();
1.69 + return new ContractImposingDelegatingConvertor( new ZigZaggingBidirectionalConvertor( oneUSD, CZK, startAmount, endAmount, stepAmount ) );
1.70 + }
1.71 +
1.72 + public void testFewQueriesForOnlineConvertor() {
1.73 + Convertor c = createOnlineCZKUSDConvertor();
1.74 + doFewQueriesForOnlineConvertor(c);
1.75 + }
1.76 +
1.77 + static void doFewQueriesForOnlineConvertor( final Convertor c ) {
1.78 + // convert $5 to CZK using c:
1.79 + final Convertor.ConversionResult r1 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 5, USD ), CZK ) );
1.80 + final MonetaryAmount a1 = r1.getNetAmount();
1.81 + //assertEquals("Result is 80 CZK");
1.82 + assertNotNull( a1 );
1.83 + assertEquals( 80.0, a1.getAmount().doubleValue() );
1.84 + assertEquals( CZK, a1.getCurrency() );
1.85 +
1.86 + // convert $8 to CZK using c:
1.87 + final Convertor.ConversionResult r2 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 8, USD ), CZK ) );
1.88 + final MonetaryAmount a2 = r2.getNetAmount();
1.89 + //assertEquals("Result is 127.92 CZK");
1.90 + assertNotNull( a2 );
1.91 + assertEquals( 12792.0, a2.getAmount().movePointRight( 2 ).doubleValue() );
1.92 + assertEquals( CZK, a2.getCurrency() );
1.93 +
1.94 + // convert $1 to CZK using c:
1.95 + final Convertor.ConversionResult r3 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 1, USD ), CZK ) );
1.96 + final MonetaryAmount a3 = r3.getNetAmount();
1.97 + //assertEquals("Result is 15.98 CZK");
1.98 + assertNotNull( a3 );
1.99 + assertEquals( 1598.0, a3.getAmount().movePointRight( 2 ).doubleValue() );
1.100 + assertEquals( CZK, a3.getCurrency() );
1.101 +
1.102 + // convert 15.97CZK to USD using c:
1.103 + final BigDecimal s4 = new BigDecimal( 1597 ).movePointLeft( 2 );
1.104 + final Convertor.ConversionResult r4 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( s4, CZK ), USD ) );
1.105 + final MonetaryAmount a4 = r4.getNetAmount();
1.106 + //assertEquals("Result is 1$");
1.107 + assertNotNull( a4 );
1.108 + assertEquals( 1.0, a4.getAmount().doubleValue() );
1.109 + assertEquals( USD, a4.getCurrency() );
1.110 + }
1.111 +
1.112 + /** Join the convertors and show they behave sane.
1.113 + */
1.114 + public void testOnlineConvertorComposition() throws Exception {
1.115 + final Convertor c = Task2Test.merge(
1.116 + createOnlineCZKUSDConvertor(),
1.117 + Task1Test.createSKKtoCZK()
1.118 + );
1.119 +
1.120 + // convert 16CZK using c:
1.121 + final Convertor.ConversionResult r4 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 16, CZK ), SKK ) );
1.122 + final MonetaryAmount a4 = r4.getNetAmount();
1.123 + // assertEquals("Result is 20 SKK");
1.124 + assertNotNull( a4 );
1.125 + assertEquals( 20.0, a4.getAmount().doubleValue() );
1.126 + assertEquals( SKK, a4.getCurrency() );
1.127 +
1.128 + // convert 500SKK to CZK using c:
1.129 + final Convertor.ConversionResult r5 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 500, SKK ), CZK ) );
1.130 + final MonetaryAmount a5 = r5.getNetAmount();
1.131 + // assertEquals("Result is 400 CZK");
1.132 + assertNotNull( a5 );
1.133 + assertEquals( 400.0, a5.getAmount().doubleValue() );
1.134 + assertEquals( CZK, a5.getCurrency() );
1.135 +
1.136 + doFewQueriesForOnlineConvertor(c);
1.137 + }
1.138 +}