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