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Diffstat (limited to 'libjava/classpath/java/util/spi/LocaleServiceProvider.java')
-rw-r--r-- | libjava/classpath/java/util/spi/LocaleServiceProvider.java | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/spi/LocaleServiceProvider.java b/libjava/classpath/java/util/spi/LocaleServiceProvider.java new file mode 100644 index 0000000..bb5b685 --- /dev/null +++ b/libjava/classpath/java/util/spi/LocaleServiceProvider.java @@ -0,0 +1,125 @@ +/* LocaleServiceProvider.java -- Superclass of locale SPIs + Copyright (C) 2007 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.util.spi; + +import java.util.Locale; + +/** + * <p> + * This is the superclass of all the {@link Locale} service + * provider interfaces or SPIs. The locale SPIs are used + * to allow for the provision of additional support for + * locale-specific data. The runtime environment has its + * own collection of locale data, but these interfaces allow + * this to be extended by external classes. + * </p> + * <p> + * Service providers are created as concrete implementations + * of these interfaces, and accessed using the extension + * mechanism, realised by {@link ServiceLoader}. When a factory + * method of one of the locale-specific classes (such as + * {@link java.text.DateFormatSymbols} or {@link java.util.Currency}) + * is called, the runtime environment is first asked to + * provide data for the specified locale. If the runtime + * environment fails to provide this, then the offer is + * made to service providers which implement the appropriate + * interface. + * </p> + * <p> + * Each provider implements the method specified by this + * class, {@link #getAvailableLocales()}. This method is + * called first to determine whether the provider will be of + * any use in providing data for the specified locale. If + * a provider is found to be capable, then a more specific + * method appropriate to the class requiring the data will + * be called. In the case of {@link java.text.DateFormatSymbols}, + * this would be + * {@link java.text.spi.DateFormatSymbols#getInstance(Locale)}. + * </p> + * <p> + * If neither a service provider nor the runtime environment + * itself can fulfill the request, a fallback procedure is + * engaged. The locale is modified by applying the first + * applicable rule: + * </p> + * <ol> + * <li>If the variant contains a <code>'_'</code>, then + * this and everything following it is trimmed.</li> + * <li>If the variant is non-empty, it is converted to + * an empty string.</li> + * <li>If the country is non-empty, it is converted to + * an empty string.</li> + * <li>If the language is non-empty, it is converted to + * an empty string.</li> + * </ol> + * <p> + * The modified locale is then used to start the same + * process again. The root locale (@link java.util.Locale#ROOT} + * must be supported by the runtime environment in order + * to terminate this cycle. + * </p> + * <p> + * Note that any names returned by the providers may + * be <code>null</code>. Returning a <code>null</code> + * name is considered equivalent to not supporting a + * particular locale. + * </p> + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.6 + */ +public abstract class LocaleServiceProvider +{ + + /** + * Constructs a new {@link LocaleServiceProvider}. + * Provided for implicit invocation by subclasses. + */ + protected LocaleServiceProvider() + { + } + + /** + * Returns an array of {@link Locale} instances, + * for which the provider can supply localized data. + * + * @return an array of supported locales. + */ + public abstract Locale[] getAvailableLocales(); + +} |