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1 package org.prevayler.demos.demo2.business;
2
3 import java.util.*;
4
5 public class Account implements java.io.Serializable  {
6
7 private long number;
8 private String holder;
9 private long balance = 0;
10 private List transactionHistory = new ArrayList();
11 private transient Set listeners;
12
13 private Account() {
14 }
15
16 Account(long number, String holder) throws InvalidHolder {
17 this.number = number;
18 holder(holder);
19 }
20
21 public long number() {
22 return number;
23 }
24
25 public String toString() { return numberString() + " - " + holder;
27 }
28
29 public String numberString() {
30 return numberString(number);
31 }
32
33 static String numberString(long number) {
34 return (new java.text.DecimalFormat ("00000").format(number));
35 }
36
37 public String holder() {
38 return holder;
39 }
40
41 public void holder(String holder) throws InvalidHolder {
42 verify(holder);
43 this.holder = holder;
44 notifyListeners();
45 }
46
47 public long balance() {
48 return balance;
49 }
50
51 public void deposit(long amount, Date timestamp) throws InvalidAmount {
52 verify(amount);
53 register(amount, timestamp);
54 }
55
56 public void withdraw(long amount, Date timestamp) throws InvalidAmount {
57 verify(amount);
58 register(-amount, timestamp);
59 }
60
61 private void register(long amount, Date timestamp) {
62 balance += amount;
63 transactionHistory.add(new AccountEntry(amount, timestamp));
64 notifyListeners();
65 }
66
67 private void verify(long amount) throws InvalidAmount {
68 if (amount <= 0) throw new InvalidAmount("Amount must be greater than zero.");
69 if (amount > 10000) throw new InvalidAmount("Amount maximum (10000) exceeded.");
70 }
71
72 public List transactionHistory() {
73 return transactionHistory;
74 }
75
76 public void addAccountListener(AccountListener listener) {
77 listeners().add(listener);
78 }
79
80 public void removeAccountListener(AccountListener listener) {
81 listeners().remove(listener);
82 }
83
84 private Set listeners() {
85 if (listeners == null) listeners = new HashSet();
86 return listeners;
87 }
88
89 private void notifyListeners() {
90 Iterator it = listeners().iterator();
91 while (it.hasNext()) {
92 ((AccountListener)it.next()).accountChanged();
93 }
94 }
95
96 public class InvalidAmount extends Exception {
97 InvalidAmount(String message) {
98 super(message);
99 }
100 }
101
102 private void verify(String holder) throws InvalidHolder {
103 if (holder == null || holder.equals("")) throw new InvalidHolder();
104 }
105
106 public class InvalidHolder extends Exception {
107 InvalidHolder() {
108 super("Invalid holder name.");
109 }
110 }
111 }
112 |
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Java API By Example, From Geeks To Geeks.