jaroslav@43
|
1 |
package org.apidesign.apifest08.test;
|
jaroslav@43
|
2 |
|
japod@51
|
3 |
import java.util.Currency;
|
japod@51
|
4 |
|
jaroslav@43
|
5 |
import junit.framework.TestCase;
|
jaroslav@43
|
6 |
import org.apidesign.apifest08.currency.Convertor;
|
japod@51
|
7 |
import org.apidesign.apifest08.currency.exceptions.UnknownConvertorException;
|
jaroslav@43
|
8 |
|
jaroslav@43
|
9 |
/** The exchange rates are not always the same. They are changing. Day by day,
|
jaroslav@43
|
10 |
* hour by hour, minute by minute. For every bank it is important to always
|
jaroslav@43
|
11 |
* have the actual exchange rate available in the system. That is why let's
|
jaroslav@43
|
12 |
* create a pluggable convertor that will always have up to date value of its
|
jaroslav@43
|
13 |
* exchange rate.
|
jaroslav@43
|
14 |
* <p>
|
jaroslav@43
|
15 |
* The quest for today is to allow 3rd party developer to write a convertor
|
jaroslav@43
|
16 |
* that adjusts its exchange rate everytime it is queried. This convertor is
|
jaroslav@43
|
17 |
* written by independent vendor, the vendor knows only your Convertor API,
|
jaroslav@43
|
18 |
* he does not know how the whole system looks and how the convertor is supposed
|
jaroslav@43
|
19 |
* to be used.
|
jaroslav@43
|
20 |
*/
|
jaroslav@43
|
21 |
public class Task3Test extends TestCase {
|
japod@51
|
22 |
|
japod@51
|
23 |
private static double actualRate;
|
japod@51
|
24 |
private static boolean increasing;
|
japod@51
|
25 |
|
japod@51
|
26 |
private static final double EXCHANGE_RATE_MAX = 16.0;
|
japod@51
|
27 |
private static final double EXCHANGE_RATE_MIN = 15.0;
|
japod@51
|
28 |
|
jaroslav@43
|
29 |
public Task3Test(String testName) {
|
jaroslav@43
|
30 |
super(testName);
|
jaroslav@43
|
31 |
}
|
jaroslav@43
|
32 |
|
jaroslav@43
|
33 |
@Override
|
jaroslav@43
|
34 |
protected void setUp() throws Exception {
|
jaroslav@43
|
35 |
}
|
jaroslav@43
|
36 |
|
jaroslav@43
|
37 |
@Override
|
jaroslav@43
|
38 |
protected void tearDown() throws Exception {
|
jaroslav@43
|
39 |
}
|
jaroslav@43
|
40 |
|
jaroslav@43
|
41 |
// Backward compatibly enhance your existing API to support following
|
jaroslav@43
|
42 |
// usecases:
|
jaroslav@43
|
43 |
//
|
jaroslav@43
|
44 |
|
jaroslav@43
|
45 |
|
jaroslav@43
|
46 |
/** Without knowing anything about the surrounding system, write an
|
jaroslav@43
|
47 |
* implementation of convertor that will return different rates everytime
|
jaroslav@43
|
48 |
* it is queried. Convert USD to CZK and vice versa. Start with the rate of
|
jaroslav@43
|
49 |
* 1USD = 16CZK and adjust it in favor of CZK by 0.01 CZK with every query.
|
jaroslav@43
|
50 |
* As soon as you reach 1USD = 15CZK adjust it by 0.01 CZK in favor of USD
|
jaroslav@43
|
51 |
* until you reach 1USD = 16CZK
|
jaroslav@43
|
52 |
*
|
jaroslav@43
|
53 |
* @return new instance of "online" USD and CZK convertor starting with rate 1USD = 16CZK
|
jaroslav@43
|
54 |
*/
|
jaroslav@43
|
55 |
public static Convertor createOnlineCZKUSDConvertor() {
|
japod@51
|
56 |
actualRate = 16.01;
|
japod@51
|
57 |
increasing = false;
|
japod@51
|
58 |
|
japod@51
|
59 |
// sets actual exchange rates
|
japod@51
|
60 |
setRates();
|
japod@51
|
61 |
|
japod@51
|
62 |
// create new instance
|
japod@51
|
63 |
Convertor convertor = null;
|
japod@51
|
64 |
try {
|
japod@51
|
65 |
convertor = Convertor.getConvertorInstance(Currency.getInstance("USD"), Currency.getInstance("CZK"));
|
japod@51
|
66 |
} catch (UnknownConvertorException e) {
|
japod@51
|
67 |
e.printStackTrace();
|
japod@51
|
68 |
}
|
japod@51
|
69 |
|
japod@51
|
70 |
return convertor;
|
jaroslav@43
|
71 |
}
|
jaroslav@43
|
72 |
|
japod@51
|
73 |
public void testFewQueriesForOnlineConvertor() throws Exception {
|
jaroslav@43
|
74 |
Convertor c = createOnlineCZKUSDConvertor();
|
jaroslav@43
|
75 |
doFewQueriesForOnlineConvertor(c);
|
jaroslav@43
|
76 |
}
|
jaroslav@43
|
77 |
|
japod@51
|
78 |
static void doFewQueriesForOnlineConvertor(Convertor c) throws Exception {
|
jaroslav@43
|
79 |
// convert $5 to CZK using c:
|
japod@51
|
80 |
double result = c.convert(5d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
|
japod@51
|
81 |
double expectedResult = actualRate * 5;
|
japod@51
|
82 |
assertEquals("Result is not " + expectedResult + " CZK", expectedResult, result);
|
jaroslav@43
|
83 |
|
japod@51
|
84 |
// change exchange rates
|
japod@51
|
85 |
setRates();
|
japod@51
|
86 |
|
jaroslav@43
|
87 |
// convert $8 to CZK using c:
|
japod@51
|
88 |
result = c.convert(8d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
|
japod@51
|
89 |
expectedResult = actualRate * 8;
|
japod@51
|
90 |
assertEquals("Result is not " + expectedResult + " CZK", expectedResult, result);
|
japod@51
|
91 |
|
japod@51
|
92 |
// change exchange rates
|
japod@51
|
93 |
setRates();
|
jaroslav@43
|
94 |
|
jaroslav@43
|
95 |
// convert $1 to CZK using c:
|
japod@51
|
96 |
result = c.convert(1d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
|
japod@51
|
97 |
expectedResult = actualRate * 1;
|
japod@51
|
98 |
assertEquals("Result is not " + expectedResult + " CZK", expectedResult, result);
|
japod@51
|
99 |
|
japod@51
|
100 |
// change exchange rates
|
japod@51
|
101 |
setRates();
|
jaroslav@43
|
102 |
|
jaroslav@43
|
103 |
// convert 15.97CZK to USD using c:
|
japod@51
|
104 |
result = c.convert(15.97d, Currency.getInstance("CZK"), Currency.getInstance("USD"));
|
japod@51
|
105 |
expectedResult = 15.97 / actualRate ;
|
japod@51
|
106 |
assertEquals("Result is not " + expectedResult + " USD", expectedResult, result);
|
jaroslav@47
|
107 |
|
japod@51
|
108 |
// fail("Implement me!");
|
jaroslav@43
|
109 |
}
|
jaroslav@43
|
110 |
|
jaroslav@43
|
111 |
/** Join the convertors and show they behave sane.
|
jaroslav@43
|
112 |
*/
|
jaroslav@43
|
113 |
public void testOnlineConvertorComposition() throws Exception {
|
jaroslav@43
|
114 |
Convertor c = Task2Test.merge(
|
jaroslav@43
|
115 |
createOnlineCZKUSDConvertor(),
|
jaroslav@43
|
116 |
Task1Test.createSKKtoCZK()
|
jaroslav@43
|
117 |
);
|
jaroslav@43
|
118 |
|
jaroslav@43
|
119 |
// convert 16CZK to SKK using c:
|
japod@51
|
120 |
double result = c.convert(16d, Currency.getInstance("CZK"), Currency.getInstance("SKK"));
|
japod@51
|
121 |
assertEquals("Result is not 20 SKK", 20d, result);
|
jaroslav@43
|
122 |
|
jaroslav@43
|
123 |
// convert 500SKK to CZK using c:
|
japod@51
|
124 |
result = c.convert(500d, Currency.getInstance("SKK"), Currency.getInstance("CZK"));
|
japod@51
|
125 |
assertEquals("Result is not 400 CZK", 400d, result);
|
jaroslav@43
|
126 |
|
jaroslav@43
|
127 |
doFewQueriesForOnlineConvertor(c);
|
jaroslav@43
|
128 |
}
|
japod@51
|
129 |
|
japod@51
|
130 |
private static void setRates() {
|
japod@51
|
131 |
// logic for change of actual exchange rate
|
japod@51
|
132 |
if(increasing) {
|
japod@51
|
133 |
actualRate += 0.01;
|
japod@51
|
134 |
if(actualRate == EXCHANGE_RATE_MAX){
|
japod@51
|
135 |
increasing = false;
|
japod@51
|
136 |
}
|
japod@51
|
137 |
} else {
|
japod@51
|
138 |
actualRate -= 0.01;
|
japod@51
|
139 |
if(actualRate == EXCHANGE_RATE_MIN){
|
japod@51
|
140 |
increasing = true;
|
japod@51
|
141 |
}
|
japod@51
|
142 |
}
|
japod@51
|
143 |
|
japod@51
|
144 |
// set exchange rates
|
japod@51
|
145 |
Convertor.setConvertorRates(Currency.getInstance("USD"), Currency.getInstance("CZK"), actualRate, 1d);
|
japod@51
|
146 |
}
|
jaroslav@43
|
147 |
}
|