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this exception to your version of the library, but you are not |
this exception to your version of the library, but you are not |
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obligated to do so. If you do not wish to do so, delete this |
obligated to do so. If you do not wish to do so, delete this |
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exception statement from your version. */ |
exception statement from your version. */ |
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|
|
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package java.util; |
package java.util; |
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|
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import java.io.ObjectStreamException; |
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import java.io.Serializable; |
import java.io.Serializable; |
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import java.text.NumberFormat; |
import java.text.NumberFormat; |
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|
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public final class Currency implements Serializable |
/** |
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* Representation of a currency for a particular locale. Each currency |
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* is identified by its ISO 4217 code, and only one instance of this |
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* class exists per currency. As a result, instances are created |
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* via the <code>getInstance()</code> methods rather than by using |
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* a constructor. |
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* |
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* @see java.util.Locale |
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* @author Guilhem Lavaux <guilhem.lavaux@free.fr> |
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* @author Dalibor Topic <robilad@kaffe.org> |
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* @author Bryce McKinlay <mckinlay@redhat.com> |
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* @author Andrew John Hughes <gnu_andrew@member.fsf.org> |
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* @since 1.4 |
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*/ |
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public final class Currency |
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implements Serializable |
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{ |
{ |
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/** |
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* For compatability with Sun's JDK |
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*/ |
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static final long serialVersionUID = -158308464356906721L; |
static final long serialVersionUID = -158308464356906721L; |
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|
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private Locale locale; |
/** |
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private ResourceBundle res; |
* The locale associated with this currency. |
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* |
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* @see #Currency(java.util.Locale) |
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* @see #getInstance(java.util.Locale) |
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* @see #getSymbol(java.util.Locale) |
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* @serial ignored. |
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*/ |
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private transient Locale locale; |
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|
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/** |
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* The resource bundle which maps the currency to |
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* a ISO 4217 currency code. |
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* |
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* @see #getCurrencyCode() |
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* @serial ignored. |
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*/ |
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private transient ResourceBundle res; |
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|
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/** |
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* The ISO 4217 currency code associated with this |
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* particular instance. |
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* |
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* @see #getCurrencyCode() |
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* @serial the ISO 4217 currency code |
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*/ |
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private String currencyCode; |
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|
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/** |
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* A cache of <code>Currency</code> instances to |
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* ensure the singleton nature of this class. The key |
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* is the locale of the currency. |
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* |
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* @see #getInstance(java.util.Locale) |
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* @see #readResolve() |
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* @serial ignored. |
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*/ |
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private transient static Map cache; |
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|
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/** |
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* Instantiates the cache. |
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*/ |
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static |
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{ |
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cache = new HashMap(); |
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} |
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|
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// For deserialization |
/** |
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* Default constructor for deserialization |
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*/ |
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private Currency () |
private Currency () |
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{ |
{ |
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} |
} |
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|
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/** |
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* Constructor to create a <code>Currency</code> object |
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* for a particular <code>Locale</code>. |
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* All components of the given locale, other than the |
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* country code, are ignored. The results of calling this |
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* method may vary over time, as the currency associated with |
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* a particular country changes. For countries without |
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* a given currency (e.g. Antarctica), the result is null. |
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* |
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* @param loc the locale for the new currency. |
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*/ |
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private Currency (Locale loc) |
private Currency (Locale loc) |
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{ |
{ |
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this.locale = loc; |
this.locale = loc; |
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this.res = ResourceBundle.getBundle ("gnu.java.locale.LocaleInformation", |
this.res = ResourceBundle.getBundle ("gnu.java.locale.LocaleInformation", |
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locale, ClassLoader.getSystemClassLoader()); |
locale, ClassLoader.getSystemClassLoader()); |
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/* Retrieve the ISO4217 currency code */ |
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try |
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{ |
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currencyCode = res.getString ("intlCurrencySymbol"); |
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} |
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catch (Exception _) |
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{ |
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currencyCode = null; |
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} |
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} |
} |
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|
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/** |
/** |
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*/ |
*/ |
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public String getCurrencyCode () |
public String getCurrencyCode () |
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{ |
{ |
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try |
return currencyCode; |
|
{ |
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return res.getString ("intlCurrencySymbol"); |
|
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} |
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catch (Exception _) |
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{ |
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return null; |
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} |
|
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} |
} |
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|
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/** |
/** |
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* @return number of digits after decimal separator for this currency. |
* Returns the number of digits which occur after the decimal point |
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* for this particular currency. For example, currencies such |
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* as the U.S. dollar, the Euro and the Great British pound have two |
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* digits following the decimal point to indicate the value which exists |
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* in the associated lower-valued coinage (cents in the case of the first |
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* two, pennies in the latter). Some currencies such as the Japanese |
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* Yen have no digits after the decimal point. In the case of pseudo |
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* currencies, such as IMF Special Drawing Rights, -1 is returned. |
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* |
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* @return the number of digits after the decimal separator for this currency. |
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*/ |
*/ |
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public int getDefaultFractionDigits () |
public int getDefaultFractionDigits () |
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{ |
{ |
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|
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/** |
/** |
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* Builds a new currency instance for this locale. |
* Builds a new currency instance for this locale. |
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* All components of the given locale, other than the |
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* country code, are ignored. The results of calling this |
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* method may vary over time, as the currency associated with |
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* a particular country changes. For countries without |
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* a given currency (e.g. Antarctica), the result is null. |
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* |
* |
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* @param locale a <code>Locale</code> instance. |
* @param locale a <code>Locale</code> instance. |
|
* |
|
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* @return a new <code>Currency</code> instance. |
* @return a new <code>Currency</code> instance. |
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* @throws NullPointerException if the locale or its |
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* country code is null. |
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* @throws IllegalArgumentException if the country of |
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* the given locale is not a supported ISO3166 code. |
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*/ |
*/ |
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public static Currency getInstance (Locale locale) |
public static Currency getInstance (Locale locale) |
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{ |
{ |
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return new Currency (locale); |
/** |
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* The new instance must be the only available instance |
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* for the currency it supports. We ensure this happens, |
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* while maintaining a suitable performance level, by |
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* creating the appropriate object on the first call to |
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* this method, and returning the cached instance on |
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* later calls. |
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*/ |
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Currency newCurrency; |
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|
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/* Attempt to get the currency from the cache */ |
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newCurrency = (Currency) cache.get(locale); |
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if (newCurrency == null) |
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{ |
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/* Create the currency for this locale */ |
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newCurrency = new Currency (locale); |
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/* Cache it */ |
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cache.put(locale, newCurrency); |
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} |
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/* Return the instance */ |
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return newCurrency; |
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} |
} |
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|
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/** |
/** |
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* Builds the currency corresponding to the specified currency code. |
* Builds the currency corresponding to the specified currency code. |
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* |
* |
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* @param currencyCode a string representing a currency code. |
* @param currencyCode a string representing a currency code. |
|
* |
|
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* @return a new <code>Currency</code> instance. |
* @return a new <code>Currency</code> instance. |
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* @throws NullPointerException if currencyCode is null. |
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* @throws IllegalArgumentException if the supplied currency code |
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* is not a supported ISO 4217 code. |
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*/ |
*/ |
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public static Currency getInstance (String currencyCode) |
public static Currency getInstance (String currencyCode) |
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{ |
{ |
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Locale[] all_locales = Locale.getAvailableLocales (); |
Locale[] allLocales = Locale.getAvailableLocales (); |
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|
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for (int i=0;i<all_locales.length;i++) |
for (int i = 0;i < allLocales.length; i++) |
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{ |
{ |
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Currency test_currency = getInstance (all_locales[i]); |
Currency testCurrency = getInstance (allLocales[i]); |
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|
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if (test_currency.getCurrencyCode() != null && |
if (testCurrency.getCurrencyCode() != null && |
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test_currency.getCurrencyCode().equals(currencyCode)) |
testCurrency.getCurrencyCode().equals(currencyCode)) |
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return test_currency; |
return testCurrency; |
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} |
} |
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/* |
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return null; |
* If we get this far, the code is not supported by any of |
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* our locales. |
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*/ |
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throw new IllegalArgumentException("The currency code, " + currencyCode + |
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", is not supported."); |
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} |
} |
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|
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/** |
/** |
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* This method returns the currency symbol. |
* This method returns the symbol which precedes or follows a |
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* value in this particular currency. In cases where there is no |
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* such symbol for the currency, the ISO 4217 currency |
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* code is returned. |
250 |
* |
* |
251 |
* @return the currency symbol. |
* @return the currency symbol, or the ISO 4217 currency code if |
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* one doesn't exist. |
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*/ |
*/ |
254 |
public String getSymbol() |
public String getSymbol() |
255 |
{ |
{ |
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try |
try |
257 |
{ |
{ |
258 |
|
/* What does this return if there is no mapping? */ |
259 |
return res.getString ("currencySymbol"); |
return res.getString ("currencySymbol"); |
260 |
} |
} |
261 |
catch (Exception _) |
catch (Exception _) |
265 |
} |
} |
266 |
|
|
267 |
/** |
/** |
268 |
* This methods returns the currency symbol expressed in the specified locale. |
* <p> |
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|
* This method returns the symbol which precedes or follows a |
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* value in this particular currency. The returned value is |
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* the symbol used to denote the currency in the specified locale. |
272 |
|
* </p> |
273 |
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* <p> |
274 |
|
* For example, a supplied locale may specify a different symbol |
275 |
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* for the currency, due to conflicts with its own currency. |
276 |
|
* This would be the case with the American currency, the dollar. |
277 |
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* Locales that also use a dollar-based currency (e.g. Canada, Australia) |
278 |
|
* need to differentiate the American dollar using 'US$' rather than '$'. |
279 |
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* So, supplying one of these locales to <code>getSymbol()</code> would |
280 |
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* return this value, rather than the standard '$'. |
281 |
|
* </p> |
282 |
|
* <p> |
283 |
|
* In cases where there is no such symbol for a particular currency, |
284 |
|
* the ISO 4217 currency code is returned. |
285 |
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* </p> |
286 |
* |
* |
287 |
* @param locale the locale to express the symbol in. |
* @param locale the locale to express the symbol in. |
288 |
* @return the currency symbol. |
* @return the currency symbol, or the ISO 4217 currency code if |
289 |
|
* one doesn't exist. |
290 |
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* @throws NullPointerException if the locale is null. |
291 |
*/ |
*/ |
292 |
public String getSymbol(Locale locale) |
public String getSymbol(Locale locale) |
293 |
{ |
{ |
294 |
// TODO. The behaviour is unclear if locale != this.locale. |
// TODO. The behaviour is unclear if locale != this.locale. |
295 |
// First we need to implement fully LocaleInformation*.java |
// First we need to implement fully LocaleInformation*.java |
296 |
|
|
297 |
|
/* |
298 |
|
* FIXME: My reading of how this method works has this implementation |
299 |
|
* as wrong. It should return a value relating to how the specified |
300 |
|
* locale handles the symbol for this currency. This implementation |
301 |
|
* seems to just do a variation of getInstance(locale). |
302 |
|
*/ |
303 |
try |
try |
304 |
{ |
{ |
305 |
ResourceBundle res = |
ResourceBundle localeResource = |
306 |
ResourceBundle.getBundle ("gnu.java.locale.LocaleInformation", |
ResourceBundle.getBundle ("gnu.java.locale.LocaleInformation", |
307 |
locale, Currency.class.getClassLoader()); |
locale, Currency.class.getClassLoader()); |
308 |
|
|
309 |
if (res.equals(this.res)) |
if (localeResource.equals(res)) |
310 |
return res.getString ("currencySymbol"); |
return localeResource.getString ("currencySymbol"); |
311 |
else |
else |
312 |
return res.getString ("intlCurrencySymbol"); |
return localeResource.getString ("intlCurrencySymbol"); |
313 |
} |
} |
314 |
catch (Exception e1) |
catch (Exception e1) |
315 |
{ |
{ |
331 |
*/ |
*/ |
332 |
public String toString() |
public String toString() |
333 |
{ |
{ |
334 |
try |
return getCurrencyCode(); |
|
{ |
|
|
return res.getString ("intlCurrencySymbol"); |
|
|
} |
|
|
catch (Exception _) |
|
|
{ |
|
|
return "(unknown currency)"; |
|
|
} |
|
335 |
} |
} |
336 |
|
|
337 |
|
/** |
338 |
|
* Resolves the deserialized object to the singleton instance for its |
339 |
|
* particular currency. The currency code of the deserialized instance |
340 |
|
* is used to return the correct instance. |
341 |
|
* |
342 |
|
* @return the singleton instance for the currency specified by the |
343 |
|
* currency code of the deserialized object. This replaces |
344 |
|
* the deserialized object as the returned object from |
345 |
|
* deserialization. |
346 |
|
* @throws ObjectStreamException if a problem occurs with deserializing |
347 |
|
* the object. |
348 |
|
*/ |
349 |
|
private Object readResolve() |
350 |
|
throws ObjectStreamException |
351 |
|
{ |
352 |
|
return getInstance(currencyCode); |
353 |
|
} |
354 |
|
|
355 |
} |
} |