1 |
package com.instantiations.example.money; |
2 |
|
3 |
import java.util.*; |
4 |
|
5 |
/** |
6 |
* A MoneyBag defers exchange rate conversions. For example adding |
7 |
* 12 Swiss Francs to 14 US Dollars is represented as a bag |
8 |
* containing the two Monies 12 CHF and 14 USD. Adding another |
9 |
* 10 Swiss francs gives a bag with 22 CHF and 14 USD. Due to |
10 |
* the deferred exchange rate conversion we can later value a |
11 |
* MoneyBag with different exchange rates. |
12 |
* |
13 |
* A MoneyBag is represented as a list of Monies and provides |
14 |
* different constructors to create a MoneyBag. |
15 |
*/ |
16 |
class MoneyBag implements IMoney { |
17 |
private Vector fMonies= new Vector(5); |
18 |
|
19 |
|
20 |
|
21 |
static IMoney create(IMoney m1, IMoney m2) { |
22 |
MoneyBag result= new MoneyBag(); |
23 |
|
24 |
m1.appendTo(result); |
25 |
m2.appendTo(result); |
26 |
|
27 |
/* $if eclipse.version < 3.5 $ */ |
28 |
System.out.println("foo"); |
29 |
/* $endif $ */ |
30 |
|
31 |
/* $if eclipse.version == 3.5 $ |
32 |
System.out.println("foo"); |
33 |
$else $ */ |
34 |
System.out.println("bar"); |
35 |
/* $endif $ */ |
36 |
|
37 |
/* $if eclipse.version != 3.5 $ */ |
38 |
System.out.println("foo"); |
39 |
/* $else $ |
40 |
System.out.println("bar"); |
41 |
$endif $ */ |
42 |
|
43 |
return result.simplify(); |
44 |
} |
45 |
public IMoney add(IMoney m) { |
46 |
return m.addMoneyBag(this); |
47 |
} |
48 |
public IMoney addMoney(Money m) { |
49 |
return MoneyBag.create(m, this); |
50 |
} |
51 |
public IMoney addMoneyBag(MoneyBag s) { |
52 |
return MoneyBag.create(s, this); |
53 |
} |
54 |
void appendBag(MoneyBag aBag) { |
55 |
for (Enumeration e= aBag.fMonies.elements(); e.hasMoreElements(); ) |
56 |
appendMoney((Money)e.nextElement()); |
57 |
} |
58 |
void appendMoney(Money aMoney) { |
59 |
if (aMoney.isZero()) return; |
60 |
IMoney old= findMoney(aMoney.currency()); |
61 |
if (old == null) { |
62 |
fMonies.addElement(aMoney); |
63 |
return; |
64 |
} |
65 |
fMonies.removeElement(old); |
66 |
IMoney sum= old.add(aMoney); |
67 |
if (sum.isZero()) |
68 |
return; |
69 |
fMonies.addElement(sum); |
70 |
} |
71 |
public boolean equals(Object anObject) { |
72 |
if (isZero()) |
73 |
if (anObject instanceof IMoney) |
74 |
return ((IMoney)anObject).isZero(); |
75 |
|
76 |
if (anObject instanceof MoneyBag) { |
77 |
MoneyBag aMoneyBag= (MoneyBag)anObject; |
78 |
if (aMoneyBag.fMonies.size() != fMonies.size()) |
79 |
return false; |
80 |
|
81 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) { |
82 |
Money m= (Money) e.nextElement(); |
83 |
if (!aMoneyBag.contains(m)) |
84 |
return false; |
85 |
} |
86 |
return true; |
87 |
} |
88 |
return false; |
89 |
} |
90 |
private Money findMoney(String currency) { |
91 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) { |
92 |
Money m= (Money) e.nextElement(); |
93 |
if (m.currency().equals(currency)) |
94 |
return m; |
95 |
} |
96 |
return null; |
97 |
} |
98 |
private boolean contains(Money m) { |
99 |
Money found= findMoney(m.currency()); |
100 |
if (found == null) return false; |
101 |
return found.amount() == m.amount(); |
102 |
} |
103 |
public int hashCode() { |
104 |
int hash= 0; |
105 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) { |
106 |
Object m= e.nextElement(); |
107 |
hash^= m.hashCode(); |
108 |
} |
109 |
return hash; |
110 |
} |
111 |
public boolean isZero() { |
112 |
return fMonies.size() == 0; |
113 |
} |
114 |
public IMoney multiply(int factor) { |
115 |
MoneyBag result= new MoneyBag(); |
116 |
if (factor != 0) { |
117 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) { |
118 |
Money m= (Money) e.nextElement(); |
119 |
result.appendMoney((Money)m.multiply(factor)); |
120 |
} |
121 |
} |
122 |
return result; |
123 |
} |
124 |
public IMoney negate() { |
125 |
MoneyBag result= new MoneyBag(); |
126 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) { |
127 |
Money m= (Money) e.nextElement(); |
128 |
result.appendMoney((Money)m.negate()); |
129 |
} |
130 |
return result; |
131 |
} |
132 |
private IMoney simplify() { |
133 |
if (fMonies.size() == 1) |
134 |
return (IMoney)fMonies.elements().nextElement(); |
135 |
return this; |
136 |
} |
137 |
public IMoney subtract(IMoney m) { |
138 |
return add(m.negate()); |
139 |
} |
140 |
public String toString() { |
141 |
StringBuffer buffer = new StringBuffer(); |
142 |
buffer.append('{'); |
143 |
for (Enumeration e= fMonies.elements(); e.hasMoreElements(); ) |
144 |
buffer.append(e.nextElement()); |
145 |
buffer.append("}"); |
146 |
return buffer.toString(); |
147 |
} |
148 |
public void appendTo(MoneyBag m) { |
149 |
m.appendBag(this); |
150 |
} |
151 |
} |
152 |
|