/*
* @(#)Currency.java 1.8 04/03/16
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.util;
import java.io.Serializable;
import java.security.AccessController;
import java.security.PrivilegedAction;
import sun.text.resources.LocaleData;
/**
* Represents a currency. Currencies are identified by their ISO 4217 currency
* codes. See the
* <a href="http://www.bsi-global.com/iso4217currency">
* ISO 4217 maintenance agency</a> for more information, including a table of
* currency codes.
* <p>
* The class is designed so that there's never more than one
* <code>Currency</code> instance for any given currency. Therefore, there's
* no public constructor. You obtain a <code>Currency</code> instance using
* the <code>getInstance</code> methods.
*
* @since 1.4
*/
public final class Currency implements Serializable {
private static final long serialVersionUID = -158308464356906721L;
/**
* ISO 4217 currency code for this currency.
*
* @serial
*/
private final String currencyCode;
/**
* Default fraction digits for this currency.
* Set from currency data tables.
*/
transient private final int defaultFractionDigits;
// class data: instance map
private static HashMap instances = new HashMap(7);
// Class data: currency data obtained from java.util.CurrencyData.
// Purpose:
// - determine valid country codes
// - determine valid currency codes
// - map country codes to currency codes
// - obtain default fraction digits for currency codes
//
// sc = special case; dfd = default fraction digits
// Simple countries are those where the country code is a prefix of the
// currency code, and there are no known plans to change the currency.
//
// table formats:
// - mainTable:
// - maps country code to 8-bit char
// - 26*26 entries, corresponding to [A-Z]*[A-Z]
// - \u007F -> not valid country
// - bit 7 - 1: special case, bits 0-4 indicate which one
// 0: simple country, bits 0-4 indicate final char of currency code
// - bits 5-6: fraction digits for simple countries, 0 for special cases
// - bits 0-4: final char for currency code for simple country, or ID of special case
// - special case IDs:
// - 0: country has no currency
// - other: index into sc* arrays + 1
// - scCutOverTimes: cut-over time in millis as returned by
// System.currentTimeMillis for special case countries that are changing
// currencies; Long.MAX_VALUE for countries that are not changing currencies
// - scOldCurrencies: old currencies for special case countries
// - scNewCurrencies: new currencies for special case countries that are
// changing currencies; null for others
// - scOldCurrenciesDFD: default fraction digits for old currencies
// - scNewCurrenciesDFD: default fraction digits for new currencies, 0 for
// countries that are not changing currencies
// - otherCurrencies: concatenation of all currency codes that are not the
// main currency of a simple country, separated by "-"
// - otherCurrenciesDFD: decimal format digits for currencies in otherCurrencies, same order
static String mainTable;
static long[] scCutOverTimes;
static String[] scOldCurrencies;
static String[] scNewCurrencies;
static int[] scOldCurrenciesDFD;
static int[] scNewCurrenciesDFD;
static String otherCurrencies;
static int[] otherCurrenciesDFD;
// handy constants - must match definitions in GenerateCurrencyData
// number of characters from A to Z
private static final int A_TO_Z = ('Z' - 'A') + 1;
// entry for invalid country codes
private static final int INVALID_COUNTRY_ENTRY = 0x007F;
// entry for countries without currency
private static final int COUNTRY_WITHOUT_CURRENCY_ENTRY = 0x0080;
// mask for simple case country entries
private static final int SIMPLE_CASE_COUNTRY_MASK = 0x0000;
// mask for simple case country entry final character
private static final int SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK = 0x001F;
// mask for simple case country entry default currency digits
private static final int SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK = 0x0060;
// shift count for simple case country entry default currency digits
private static final int SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT = 5;
// mask for special case country entries
private static final int SPECIAL_CASE_COUNTRY_MASK = 0x0080;
// mask for special case country index
private static final int SPECIAL_CASE_COUNTRY_INDEX_MASK = 0x001F;
// delta from entry index component in main table to index into special case tables
private static final int SPECIAL_CASE_COUNTRY_INDEX_DELTA = 1;
// mask for distinguishing simple and special case countries
private static final int COUNTRY_TYPE_MASK = SIMPLE_CASE_COUNTRY_MASK | SPECIAL_CASE_COUNTRY_MASK;
static {
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
try {
Class data = Class.forName("java.util.CurrencyData");
mainTable = (String) data.getDeclaredField("mainTable").get(data);
scCutOverTimes = (long[]) data.getDeclaredField("scCutOverTimes").get(data);
scOldCurrencies = (String[]) data.getDeclaredField("scOldCurrencies").get(data);
scNewCurrencies = (String[]) data.getDeclaredField("scNewCurrencies").get(data);
scOldCurrenciesDFD = (int[]) data.getDeclaredField("scOldCurrenciesDFD").get(data);
scNewCurrenciesDFD = (int[]) data.getDeclaredField("scNewCurrenciesDFD").get(data);
otherCurrencies = (String) data.getDeclaredField("otherCurrencies").get(data);
otherCurrenciesDFD = (int[]) data.getDeclaredField("otherCurrenciesDFD").get(data);
} catch (ClassNotFoundException e) {
throw new InternalError();
} catch (NoSuchFieldException e) {
throw new InternalError();
} catch (IllegalAccessException e) {
throw new InternalError();
}
return null;
}
});
}
/**
* Constructs a <code>Currency</code> instance. The constructor is private
* so that we can insure that there's never more than one instance for a
* given currency.
*/
private Currency(String currencyCode, int defaultFractionDigits) {
this.currencyCode = currencyCode;
this.defaultFractionDigits = defaultFractionDigits;
}
/**
* Returns the <code>Currency</code> instance for the given currency code.
*
* @param currencyCode the ISO 4217 code of the currency
* @return the <code>Currency</code> instance for the given currency code
* @exception NullPointerException if <code>currencyCode</code> is null
* @exception IllegalArgumentException if <code>currencyCode</code> is not
* a supported ISO 4217 code.
*/
public static Currency getInstance(String currencyCode) {
return getInstance(currencyCode, Integer.MIN_VALUE);
}
private static Currency getInstance(String currencyCode, int defaultFractionDigits) {
synchronized (instances) {
// Try to look up the currency code in the instances table.
// This does the null pointer check as a side effect.
// Also, if there already is an entry, the currencyCode must be valid.
Currency instance = (Currency) instances.get(currencyCode);
if (instance != null) {
return instance;
}
if (defaultFractionDigits == Integer.MIN_VALUE) {
// Currency code not internally generated, need to verify first
// A currency code must have 3 characters and exist in the main table
// or in the list of other currencies.
if (currencyCode.length() != 3) {
throw new IllegalArgumentException();
}
char char1 = currencyCode.charAt(0);
char char2 = currencyCode.charAt(1);
int tableEntry = getMainTableEntry(char1, char2);
if ((tableEntry & COUNTRY_TYPE_MASK) == SIMPLE_CASE_COUNTRY_MASK
&& tableEntry != INVALID_COUNTRY_ENTRY
&& currencyCode.charAt(2) - 'A' == (tableEntry & SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK)) {
defaultFractionDigits = (tableEntry & SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK) >> SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT;
} else {
// Check for '-' separately so we don't get false hits in the table.
if (currencyCode.charAt(2) == '-') {
throw new IllegalArgumentException();
}
int index = otherCurrencies.indexOf(currencyCode);
if (index == -1) {
throw new IllegalArgumentException();
}
defaultFractionDigits = otherCurrenciesDFD[index / 4];
}
}
instance = new Currency(currencyCode, defaultFractionDigits);
instances.put(currencyCode, instance);
return instance;
}
}
/**
* Returns the <code>Currency</code> instance for the country of the
* given locale. The language and variant components of the locale
* are ignored. The result may vary over time, as countries change their
* currencies. For example, for the original member countries of the
* European Monetary Union, the method returns the old national currencies
* until December 31, 2001, and the Euro from January 1, 2002, local time
* of the respective countries.
* <p>
* The method returns <code>null</code> for territories that don't
* have a currency, such as Antarctica.
*
* @param locale the locale for whose country a <code>Currency</code>
* instance is needed
* @return the <code>Currency</code> instance for the country of the given
* locale, or null
* @exception NullPointerException if <code>locale</code> or its country
* code is null
* @exception IllegalArgumentException if the country of the given locale
* is not a supported ISO 3166 country code.
*/
public static Currency getInstance(Locale locale) {
String country = locale.getCountry();
if (country == null) {
throw new NullPointerException();
}
if (country.length() != 2) {
throw new IllegalArgumentException();
}
char char1 = country.charAt(0);
char char2 = country.charAt(1);
int tableEntry = getMainTableEntry(char1, char2);
if ((tableEntry & COUNTRY_TYPE_MASK) == SIMPLE_CASE_COUNTRY_MASK
&& tableEntry != INVALID_COUNTRY_ENTRY) {
char finalChar = (char) ((tableEntry & SIMPLE_CASE_COUNTRY_FINAL_CHAR_MASK) + 'A');
int defaultFractionDigits = (tableEntry & SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_MASK) >> SIMPLE_CASE_COUNTRY_DEFAULT_DIGITS_SHIFT;
StringBuffer sb = new StringBuffer(country);
sb.append(finalChar);
return getInstance(sb.toString(), defaultFractionDigits);
} else {
// special cases
if (tableEntry == INVALID_COUNTRY_ENTRY) {
throw new IllegalArgumentException();
}
if (tableEntry == COUNTRY_WITHOUT_CURRENCY_ENTRY) {
return null;
} else {
int index = (tableEntry & SPECIAL_CASE_COUNTRY_INDEX_MASK) - SPECIAL_CASE_COUNTRY_INDEX_DELTA;
if (scCutOverTimes[index] == Long.MAX_VALUE || System.currentTimeMillis() < scCutOverTimes[index]) {
return getInstance(scOldCurrencies[index], scOldCurrenciesDFD[index]);
} else {
return getInstance(scNewCurrencies[index], scNewCurrenciesDFD[index]);
}
}
}
}
/**
* Gets the ISO 4217 currency code of this currency.
*
* @return the ISO 4217 currency code of this currency.
*/
public String getCurrencyCode() {
return currencyCode;
}
/**
* Gets the symbol of this currency for the default locale.
* For example, for the US Dollar, the symbol is "$" if the default
* locale is the US, while for other locales it may be "US$". If no
* symbol can be determined, the ISO 4217 currency code is returned.
*
* @return the symbol of this currency for the default locale
*/
public String getSymbol() {
return getSymbol(Locale.getDefault());
}
/**
* Gets the symbol of this currency for the specified locale.
* For example, for the US Dollar, the symbol is "$" if the specified
* locale is the US, while for other locales it may be "US$". If no
* symbol can be determined, the ISO 4217 currency code is returned.
*
* @param locale the locale for which a display name for this currency is
* needed
* @return the symbol of this currency for the specified locale
* @exception NullPointerException if <code>locale</code> is null
*/
public String getSymbol(Locale locale) {
ResourceBundle bundle;
try {
bundle = LocaleData.getLocaleElements(locale);
} catch (MissingResourceException e) {
// use currency code as symbol of last resort
return currencyCode;
}
String[][] symbols =
(String[][]) bundle.getObject("CurrencySymbols");
if (symbols != null) {
for (int i = 0; i < symbols.length; i++) {
if (symbols[i][0].equals(currencyCode)) {
return symbols[i][1];
}
}
}
// use currency code as symbol of last resort
return currencyCode;
}
/**
* Gets the default number of fraction digits used with this currency.
* For example, the default number of fraction digits for the Euro is 2,
* while for the Japanese Yen it's 0.
* In the case of pseudo-currencies, such as IMF Special Drawing Rights,
* -1 is returned.
*
* @return the default number of fraction digits used with this currency
*/
public int getDefaultFractionDigits() {
return defaultFractionDigits;
}
/**
* Returns the ISO 4217 currency code of this currency.
*
* @return the ISO 4217 currency code of this currency
*/
public String toString() {
return currencyCode;
}
/**
* Resolves instances being deserialized to a single instance per currency.
*/
private Object readResolve() {
return getInstance(currencyCode);
}
/**
* Gets the main table entry for the country whose country code consists
* of char1 and char2.
*/
private static int getMainTableEntry(char char1, char char2) {
if (char1 < 'A' || char1 > 'Z' || char2 < 'A' || char2 > 'Z') {
throw new IllegalArgumentException();
}
return mainTable.charAt((char1 - 'A') * A_TO_Z + (char2 - 'A'));
}
}
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