1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/task2/solution07/test/org/apidesign/apifest08/test/Task2Test.java Tue Oct 07 00:24:22 2008 +0200
1.3 @@ -0,0 +1,192 @@
1.4 +package org.apidesign.apifest08.test;
1.5 +
1.6 +import java.util.Currency;
1.7 +import junit.framework.TestCase;
1.8 +import org.apidesign.apifest08.currency.ConversionRate;
1.9 +import org.apidesign.apifest08.currency.Convertor;
1.10 +import org.apidesign.apifest08.currency.IllegalRequestSubtypeException;
1.11 +import org.apidesign.apifest08.currency.MonetaryAmount;
1.12 +import org.apidesign.apifest08.currency.TableConvertor;
1.13 +
1.14 +/** There are many currencies around the world and many banks manipulate
1.15 + * with more than one or two at the same time. As banks are usually the
1.16 + * best paying clients, which is true even in case of your Convertor API,
1.17 + * it is reasonable to listen to their requests.
1.18 + * <p>
1.19 + * The quest for today is to enhance your existing convertor API to hold
1.20 + * information about many currencies and allow conversions between any of them.
1.21 + * Also, as conversion rates for diferent currencies usually arise from various
1.22 + * bank departments, there is another important need. There is a need to
1.23 + * compose two convertors into one by merging all the information about
1.24 + * currencies they know about.
1.25 + */
1.26 +public class Task2Test extends TestCase {
1.27 + public Task2Test(String testName) {
1.28 + super(testName);
1.29 + }
1.30 +
1.31 + @Override
1.32 + protected void setUp() throws Exception {
1.33 + }
1.34 +
1.35 + @Override
1.36 + protected void tearDown() throws Exception {
1.37 + }
1.38 +
1.39 + protected static final Currency CZK = Currency.getInstance( "CZK" );
1.40 + protected static final Currency SKK = Currency.getInstance( "SKK" );
1.41 + protected static final Currency USD = Currency.getInstance( "USD" );
1.42 +
1.43 + // As in Task1Test, keep in mind, that there are three parts
1.44 + // of the whole system:
1.45 + // 1. there is someone who knows the current exchange rate
1.46 + // 2. there is someone who wants to do the conversion
1.47 + // 3. there is the API between 1. and 2. which allows them to communicate
1.48 + //
1.49 + // Please backward compatibly enhance your existing API to support following
1.50 + // usecases:
1.51 + //
1.52 +
1.53 + /** Create convertor that understands two currencies, CZK and
1.54 + * SKK. Make 100 SKK == 75 CZK. This is method for the group of users that
1.55 + * knows the exchange rate, and needs to use the API to create objects
1.56 + * with the exchange rate. Anyone shall be ready to call this method without
1.57 + * any other method being called previously. The API itself shall know
1.58 + * nothing about any rates, before this method is called.
1.59 + */
1.60 + public static Convertor createTripleConvertor() {
1.61 + // Rates: 1USD = 15CZK
1.62 + // Rates: 1USD = 20SKK
1.63 + // Rates: 75CZK = 100SKK
1.64 + final TableConvertor convertor = new TableConvertor();
1.65 + final MonetaryAmount amountInUSD = new MonetaryAmount( 1, USD );
1.66 + final MonetaryAmount amountInCZK = new MonetaryAmount( 15, CZK );
1.67 + final MonetaryAmount amountInSKK = new MonetaryAmount( 20, SKK );
1.68 + convertor.putIntoTable( new ConversionRate( amountInCZK, amountInUSD ) );
1.69 + convertor.putIntoTable( new ConversionRate( amountInUSD, amountInCZK ) );
1.70 + convertor.putIntoTable( new ConversionRate( amountInSKK, amountInUSD ) );
1.71 + convertor.putIntoTable( new ConversionRate( amountInUSD, amountInSKK ) );
1.72 + convertor.putIntoTable( new ConversionRate( amountInSKK, amountInCZK ) );
1.73 + convertor.putIntoTable( new ConversionRate( amountInCZK, amountInSKK ) );
1.74 + return new ContractImposingDelegatingConvertor( convertor ).test();
1.75 + }
1.76 +
1.77 + /** Define convertor that understands three currencies. Use it.
1.78 + */
1.79 + public void testConvertorForUSDandCZKandSKK() throws Exception {
1.80 + final Convertor c = createTripleConvertor();
1.81 +
1.82 + // convert $5 to CZK using c:
1.83 + final Convertor.ConversionResult r1 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 5, USD ), CZK ) );
1.84 + final MonetaryAmount a1 = r1.getNetAmount();
1.85 + // assertEquals("Result is 75 CZK");
1.86 + assertNotNull( a1 );
1.87 + assertEquals( 75.0, a1.getAmount().doubleValue() );
1.88 + assertEquals( CZK, a1.getCurrency() );
1.89 +
1.90 + // convert $5 to SKK using c:
1.91 + final Convertor.ConversionResult r2 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 5, USD ), SKK ) );
1.92 + final MonetaryAmount a2 = r2.getNetAmount();
1.93 + // assertEquals("Result is 100 SKK");
1.94 + assertNotNull( a2 );
1.95 + assertEquals( 100.0, a2.getAmount().doubleValue() );
1.96 + assertEquals( SKK, a2.getCurrency() );
1.97 +
1.98 + // convert 200SKK to CZK using c:
1.99 + final Convertor.ConversionResult r3 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 200, SKK ), CZK ) );
1.100 + final MonetaryAmount a3 = r3.getNetAmount();
1.101 + // assertEquals("Result is 150 CZK");
1.102 + assertNotNull( a3 );
1.103 + assertEquals( 150.0, a3.getAmount().doubleValue() );
1.104 + assertEquals( CZK, a3.getCurrency() );
1.105 +
1.106 + // convert 200SKK to USK using c:
1.107 + final Convertor.ConversionResult r4 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 200, SKK ), USD ) );
1.108 + final MonetaryAmount a4 = r4.getNetAmount();
1.109 + // assertEquals("Result is 10 USD");
1.110 + assertNotNull( a4 );
1.111 + assertEquals( 10.0, a4.getAmount().doubleValue() );
1.112 + assertEquals( USD, a4.getCurrency() );
1.113 + }
1.114 +
1.115 + /** Merge all currency rates of convertor 1 with convertor 2.
1.116 + * Implement this using your API, preferably this method just delegates
1.117 + * into some API method which does the actual work, without requiring
1.118 + * API clients to code anything complex.
1.119 + */
1.120 + public static Convertor merge( final Convertor one, final Convertor two ) {
1.121 + return new Convertor() {
1.122 +
1.123 + public ConversionResult convert( ConversionRequest req ) throws IllegalRequestSubtypeException {
1.124 + final ConversionResult res1 = one.convert( req );
1.125 + final ConversionResult res2 = two.convert( req );
1.126 + if ( res1.getNetAmount() != null ) {
1.127 + if ( res2.getNetAmount() != null ) {
1.128 + // TODO check if they arrive at the same thing
1.129 + return res1;
1.130 + } else {
1.131 + return res1;
1.132 + }
1.133 + } else {
1.134 + if ( res2.getNetAmount() != null ) {
1.135 + return res2;
1.136 + } else {
1.137 + // neither converts
1.138 + return new ConversionResult( null );
1.139 + }
1.140 + }
1.141 + }
1.142 +
1.143 + };
1.144 + }
1.145 +
1.146 + /** Join the convertors from previous task, Task1Test and show that it
1.147 + * can be used to do reasonable conversions.
1.148 + */
1.149 + public void testConvertorComposition() throws Exception {
1.150 + final Convertor c = merge(
1.151 + Task1Test.createCZKtoUSD(),
1.152 + Task1Test.createSKKtoCZK()
1.153 + );
1.154 +
1.155 + // convert $5 to CZK using c:
1.156 + final Convertor.ConversionResult r1 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 5, USD ), CZK ) );
1.157 + final MonetaryAmount a1 = r1.getNetAmount();
1.158 + // assertEquals("Result is 85 CZK");
1.159 + assertNotNull( a1 );
1.160 + assertEquals( 85.0, a1.getAmount().doubleValue() );
1.161 + assertEquals( CZK, a1.getCurrency() );
1.162 +
1.163 + // convert $8 to CZK
1.164 + final Convertor.ConversionResult r2 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 8, USD ), CZK ) );
1.165 + final MonetaryAmount a2 = r2.getNetAmount();
1.166 + // assertEquals("Result is 136 CZK");
1.167 + assertNotNull( a2 );
1.168 + assertEquals( 136.0, a2.getAmount().doubleValue() );
1.169 + assertEquals( CZK, a2.getCurrency() );
1.170 +
1.171 + // convert 1003CZK to USD
1.172 + final Convertor.ConversionResult r3 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 1003, CZK ), USD ) );
1.173 + final MonetaryAmount a3 = r3.getNetAmount();
1.174 + // assertEquals("Result is 59 USD");
1.175 + assertNotNull( a3 );
1.176 + assertEquals( 59.0, a3.getAmount().doubleValue() );
1.177 + assertEquals( USD, a3.getCurrency() );
1.178 +
1.179 + // convert 16CZK using c:
1.180 + final Convertor.ConversionResult r4 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 16, CZK ), SKK ) );
1.181 + final MonetaryAmount a4 = r4.getNetAmount();
1.182 + // assertEquals("Result is 20 SKK");
1.183 + assertNotNull( a4 );
1.184 + assertEquals( 20.0, a4.getAmount().doubleValue() );
1.185 + assertEquals( SKK, a4.getCurrency() );
1.186 +
1.187 + // convert 500SKK to CZK using c:
1.188 + final Convertor.ConversionResult r5 = c.convert( new Convertor.ConversionRequest( new MonetaryAmount( 500, SKK ), CZK ) );
1.189 + final MonetaryAmount a5 = r5.getNetAmount();
1.190 + // assertEquals("Result is 400 CZK");
1.191 + assertNotNull( a5 );
1.192 + assertEquals( 400.0, a5.getAmount().doubleValue() );
1.193 + assertEquals( CZK, a5.getCurrency() );
1.194 + }
1.195 +}