| Currency.java |
1 /*
2 * %W% %E%
3 *
4 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
5 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6 */
7
8 package java.util;
9
10 import java.io.Serializable;
11 import java.security.AccessController;
12 import java.security.PrivilegedAction;
13 import java.util.spi.CurrencyNameProvider;
14 import java.util.spi.LocaleServiceProvider;
15 import sun.util.LocaleServiceProviderPool;
16 import sun.util.resources.LocaleData;
17
18
19 /**
20 * Represents a currency. Currencies are identified by their ISO 4217 currency
21 * codes. Visit the <a href="http://www.bsi-global.com/">
22 * BSi web site</a> for more information, including a table of
23 * currency codes.
24 * <p>
25 * The class is designed so that there's never more than one
26 * <code>Currency</code> instance for any given currency. Therefore, there's
27 * no public constructor. You obtain a <code>Currency</code> instance using
28 * the <code>getInstance</code> methods.
29 *
30 * @since 1.4
31 */
32 public final class Currency implements Serializable {
33
34 private static final long serialVersionUID = -158308464356906721L;
35
36 /**
37 * ISO 4217 currency code for this currency.
38 *
39 * @serial
40 */
41 private final String currencyCode;
42
43 /**
44 * Default fraction digits for this currency.
45 * Set from currency data tables.
46 */
47 transient private final int defaultFractionDigits;
48
49
50 // class data: instance map
51
52 private static HashMap instances = new HashMap(7);
53
54
55 // Class data: currency data obtained from java.util.CurrencyData.
56 // Purpose:
57 // - determine valid country codes
58 // - determine valid currency codes
59 // - map country codes to currency codes
60 // - obtain default fraction digits for currency codes
61 //
62 // sc = special case; dfd = default fraction digits
63 // Simple countries are those where the country code is a prefix of the
64 // currency code, and there are no known plans to change the currency.
65 //
66 // table formats:
67 // - mainTable:
68 // - maps country code to 8-bit char
69 // - 26*26 entries, corresponding to [A-Z]*[A-Z]
70 // \u007F - -> not valid country
71 // - bit 7 - 1: special case, bits 0-4 indicate which one
72 // 0: simple country, bits 0-4 indicate final char of currency code
73 // - bits 5-6: fraction digits for simple countries, 0 for special cases
74 // - bits 0-4: final char for currency code for simple country, or ID of special case
75 // - special case IDs:
76 // - 0: country has no currency
77 // - other: index into sc* arrays + 1
78 // - scCutOverTimes: cut-over time in millis as returned by
79 // System.currentTimeMillis for special case countries that are changing
80 // currencies; Long.MAX_VALUE for countries that are not changing currencies
81 // - scOldCurrencies: old currencies for special case countries
82 // - scNewCurrencies: new currencies for special case countries that are
83 // changing currencies; null for others
84 // - scOldCurrenciesDFD: default fraction digits for old currencies
85 // - scNewCurrenciesDFD: default fraction digits for new currencies, 0 for
86 // countries that are not changing currencies
87 // - otherCurrencies: concatenation of all currency codes that are not the
88 // main currency of a simple country, separated by "-"
89 // - otherCurrenciesDFD: decimal format digits for currencies in otherCurrencies, same order
90
91 static String mainTable;
92 static long[] scCutOverTimes;
93 static String[] scOldCurrencies;
94 static String[] scNewCurrencies;
95 static int[] scOldCurrenciesDFD;
96 static int[] scNewCurrenciesDFD;
97 static String otherCurrencies;
98 static int[] otherCurrenciesDFD;
99
100 // handy constants - must match definitions in GenerateCurrencyData
101 // number of characters from A to Z
102 private static final int A_TO_Z = ('Z' - 'A') + 1;
103 // entry for invalid country codes
104 private static final int INVALID_COUNTRY_ENTRY = 0x007F;
105 // entry for countries without currency
106 private static final int COUNTRY_WITHOUT_CURRENCY_ENTRY = 0x0080;
107 // mask for simple case country entries
108 private static final int SIMPLE_CASE_COUNTRY_MASK = 0x0000;
109 // mask for simple case country entry final character
110 private static final int SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK = 0x001F;
111 // mask for simple case country entry default currency digits
112 private static final int SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK = 0x0060;
113 // shift count for simple case country entry default currency digits
114 private static final int SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT = 5;
115 // mask for special case country entries
116 private static final int SPECIAL_CASE_COUNTRY_MASK = 0x0080;
117 // mask for special case country index
118 private static final int SPECIAL_CASE_COUNTRY_INDEX_MASK = 0x001F;
119 // delta from entry index component in main table to index into special case tables
120 private static final int SPECIAL_CASE_COUNTRY_INDEX_DELTA = 1;
121 // mask for distinguishing simple and special case countries
122 private static final int COUNTRY_TYPE_MASK = SIMPLE_CASE_COUNTRY_MASK | SPECIAL_CASE_COUNTRY_MASK;
123
124 static {
125 AccessController.doPrivileged(new PrivilegedAction() {
126 public Object run() {
127 try {
128 Class data = Class.forName("java.util.CurrencyData");
129 mainTable = (String) data.getDeclaredField("mainTable").get(data);
130 scCutOverTimes = (long[]) data.getDeclaredField("scCutOverTimes").get(data);
131 scOldCurrencies = (String[]) data.getDeclaredField("scOldCurrencies").get(data);
132 scNewCurrencies = (String[]) data.getDeclaredField("scNewCurrencies").get(data);
133 scOldCurrenciesDFD = (int[]) data.getDeclaredField("scOldCurrenciesDFD").get(data);
134 scNewCurrenciesDFD = (int[]) data.getDeclaredField("scNewCurrenciesDFD").get(data);
135 otherCurrencies = (String) data.getDeclaredField("otherCurrencies").get(data);
136 otherCurrenciesDFD = (int[]) data.getDeclaredField("otherCurrenciesDFD").get(data);
137 } catch (ClassNotFoundException e) {
138 throw new InternalError();
139 } catch (NoSuchFieldException e) {
140 throw new InternalError();
141 } catch (IllegalAccessException e) {
142 throw new InternalError();
143 }
144 return null;
145 }
146 });
147 }
148
149
150 /**
151 * Constructs a <code>Currency</code> instance. The constructor is private
152 * so that we can insure that there's never more than one instance for a
153 * given currency.
154 */
155 private Currency(String currencyCode, int defaultFractionDigits) {
156 this.currencyCode = currencyCode;
157 this.defaultFractionDigits = defaultFractionDigits;
158 }
159
160 /**
161 * Returns the <code>Currency</code> instance for the given currency code.
162 *
163 * @param currencyCode the ISO 4217 code of the currency
164 * @return the <code>Currency</code> instance for the given currency code
165 * @exception NullPointerException if <code>currencyCode</code> is null
166 * @exception IllegalArgumentException if <code>currencyCode</code> is not
167 * a supported ISO 4217 code.
168 */
169 public static Currency getInstance(String currencyCode) {
170 return getInstance(currencyCode, Integer.MIN_VALUE);
171 }
172
173 private static Currency getInstance(String currencyCode, int defaultFractionDigits) {
174 synchronized (instances) {
175 // Try to look up the currency code in the instances table.
176 // This does the null pointer check as a side effect.
177 // Also, if there already is an entry, the currencyCode must be valid.
178 Currency instance = (Currency) instances.get(currencyCode);
179 if (instance != null) {
180 return instance;
181 }
182
183 if (defaultFractionDigits == Integer.MIN_VALUE) {
184 // Currency code not internally generated, need to verify first
185 // A currency code must have 3 characters and exist in the main table
186 // or in the list of other currencies.
187 if (currencyCode.length() != 3) {
188 throw new IllegalArgumentException();
189 }
190 char char1 = currencyCode.charAt(0);
191 char char2 = currencyCode.charAt(1);
192 int tableEntry = getMainTableEntry(char1, char2);
193 if ((tableEntry & COUNTRY_TYPE_MASK) == SIMPLE_CASE_COUNTRY_MASK
194 && tableEntry != INVALID_COUNTRY_ENTRY
195 && currencyCode.charAt(2) - 'A' == (tableEntry & SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK)) {
196 defaultFractionDigits = (tableEntry & SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK) >> SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT;
197 } else {
198 // Check for '-' separately so we don't get false hits in the table.
199 if (currencyCode.charAt(2) == '-') {
200 throw new IllegalArgumentException();
201 }
202 int index = otherCurrencies.indexOf(currencyCode);
203 if (index == -1) {
204 throw new IllegalArgumentException();
205 }
206 defaultFractionDigits = otherCurrenciesDFD[index / 4];
207 }
208 }
209
210 instance = new Currency(currencyCode, defaultFractionDigits);
211 instances.put(currencyCode, instance);
212 return instance;
213 }
214 }
215
216 /**
217 * Returns the <code>Currency</code> instance for the country of the
218 * given locale. The language and variant components of the locale
219 * are ignored. The result may vary over time, as countries change their
220 * currencies. For example, for the original member countries of the
221 * European Monetary Union, the method returns the old national currencies
222 * until December 31, 2001, and the Euro from January 1, 2002, local time
223 * of the respective countries.
224 * <p>
225 * The method returns <code>null</code> for territories that don't
226 * have a currency, such as Antarctica.
227 *
228 * @param locale the locale for whose country a <code>Currency</code>
229 * instance is needed
230 * @return the <code>Currency</code> instance for the country of the given
231 * locale, or null
232 * @exception NullPointerException if <code>locale</code> or its country
233 * code is null
234 * @exception IllegalArgumentException if the country of the given locale
235 * is not a supported ISO 3166 country code.
236 */
237 public static Currency getInstance(Locale locale) {
238 String country = locale.getCountry();
239 if (country == null) {
240 throw new NullPointerException();
241 }
242
243 if (country.length() != 2) {
244 throw new IllegalArgumentException();
245 }
246
247 char char1 = country.charAt(0);
248 char char2 = country.charAt(1);
249 int tableEntry = getMainTableEntry(char1, char2);
250 if ((tableEntry & COUNTRY_TYPE_MASK) == SIMPLE_CASE_COUNTRY_MASK
251 && tableEntry != INVALID_COUNTRY_ENTRY) {
252 char finalChar = (char) ((tableEntry & SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK) + 'A');
253 int defaultFractionDigits = (tableEntry & SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK) >> SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT;
254 StringBuffer sb = new StringBuffer(country);
255 sb.append(finalChar);
256 return getInstance(sb.toString(), defaultFractionDigits);
257 } else {
258 // special cases
259 if (tableEntry == INVALID_COUNTRY_ENTRY) {
260 throw new IllegalArgumentException();
261 }
262 if (tableEntry == COUNTRY_WITHOUT_CURRENCY_ENTRY) {
263 return null;
264 } else {
265 int index = (tableEntry & SPECIAL_CASE_COUNTRY_INDEX_MASK) - SPECIAL_CASE_COUNTRY_INDEX_DELTA;
266 if (scCutOverTimes[index] == Long.MAX_VALUE || System.currentTimeMillis() < scCutOverTimes[index]) {
267 return getInstance(scOldCurrencies[index], scOldCurrenciesDFD[index]);
268 } else {
269 return getInstance(scNewCurrencies[index], scNewCurrenciesDFD[index]);
270 }
271 }
272 }
273 }
274
275 /**
276 * Gets the ISO 4217 currency code of this currency.
277 *
278 * @return the ISO 4217 currency code of this currency.
279 */
280 public String getCurrencyCode() {
281 return currencyCode;
282 }
283
284 /**
285 * Gets the symbol of this currency for the default locale.
286 * For example, for the US Dollar, the symbol is "$" if the default
287 * locale is the US, while for other locales it may be "US$". If no
288 * symbol can be determined, the ISO 4217 currency code is returned.
289 *
290 * @return the symbol of this currency for the default locale
291 */
292 public String getSymbol() {
293 return getSymbol(Locale.getDefault());
294 }
295
296 /**
297 * Gets the symbol of this currency for the specified locale.
298 * For example, for the US Dollar, the symbol is "$" if the specified
299 * locale is the US, while for other locales it may be "US$". If no
300 * symbol can be determined, the ISO 4217 currency code is returned.
301 *
302 * @param locale the locale for which a display name for this currency is
303 * needed
304 * @return the symbol of this currency for the specified locale
305 * @exception NullPointerException if <code>locale</code> is null
306 */
307 public String getSymbol(Locale locale) {
308 try {
309 // Check whether a provider can provide an implementation that's closer
310 // to the requested locale than what the Java runtime itself can provide.
311 LocaleServiceProviderPool pool =
312 LocaleServiceProviderPool.getPool(CurrencyNameProvider.class);
313
314 if (pool.hasProviders()) {
315 // Assuming that all the country locales include necessary currency
316 // symbols in the Java runtime's resources, so there is no need to
317 // examine whether Java runtime's currency resource bundle is missing
318 // names. Therefore, no resource bundle is provided for calling this
319 // method.
320 String symbol = pool.getLocalizedObject(
321 CurrencyNameGetter.INSTANCE,
322 locale, null, currencyCode);
323 if (symbol != null) {
324 return symbol;
325 }
326 }
327
328 ResourceBundle bundle = LocaleData.getCurrencyNames(locale);
329 return bundle.getString(currencyCode);
330 } catch (MissingResourceException e) {
331 // use currency code as symbol of last resort
332 return currencyCode;
333 }
334 }
335
336 /**
337 * Gets the default number of fraction digits used with this currency.
338 * For example, the default number of fraction digits for the Euro is 2,
339 * while for the Japanese Yen it's 0.
340 * In the case of pseudo-currencies, such as IMF Special Drawing Rights,
341 * -1 is returned.
342 *
343 * @return the default number of fraction digits used with this currency
344 */
345 public int getDefaultFractionDigits() {
346 return defaultFractionDigits;
347 }
348
349 /**
350 * Returns the ISO 4217 currency code of this currency.
351 *
352 * @return the ISO 4217 currency code of this currency
353 */
354 public String toString() {
355 return currencyCode;
356 }
357
358 /**
359 * Resolves instances being deserialized to a single instance per currency.
360 */
361 private Object readResolve() {
362 return getInstance(currencyCode);
363 }
364
365 /**
366 * Gets the main table entry for the country whose country code consists
367 * of char1 and char2.
368 */
369 private static int getMainTableEntry(char char1, char char2) {
370 if (char1 < 'A' || char1 > 'Z' || char2 < 'A' || char2 > 'Z') {
371 throw new IllegalArgumentException();
372 }
373 return mainTable.charAt((char1 - 'A') * A_TO_Z + (char2 - 'A'));
374 }
375
376 /**
377 * Obtains a localized currency names from a CurrencyNameProvider
378 * implementation.
379 */
380 private static class CurrencyNameGetter
381 implements LocaleServiceProviderPool.LocalizedObjectGetter<CurrencyNameProvider,
382 String> {
383 private static final CurrencyNameGetter INSTANCE = new CurrencyNameGetter();
384
385 public String getObject(CurrencyNameProvider currencyNameProvider,
386 Locale locale,
387 String key,
388 Object... params) {
389 assert params.length == 0;
390 return currencyNameProvider.getSymbol(key, locale);
391 }
392 }
393 }
394