| /* |
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| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
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| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
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| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
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| |
| package java.util.spi; |
| |
| import java.util.Locale; |
| |
| /** |
| * <p> |
| * This is the super class of all the locale sensitive service provider |
| * interfaces (SPIs). |
| * <p> |
| * Locale sensitive service provider interfaces are interfaces that |
| * correspond to locale sensitive classes in the <code>java.text</code> |
| * and <code>java.util</code> packages. The interfaces enable the |
| * construction of locale sensitive objects and the retrieval of |
| * localized names for these packages. Locale sensitive factory methods |
| * and methods for name retrieval in the <code>java.text</code> and |
| * <code>java.util</code> packages use implementations of the provider |
| * interfaces to offer support for locales beyond the set of locales |
| * supported by the Java runtime environment itself. |
| * <p> |
| * <h4>Packaging of Locale Sensitive Service Provider Implementations</h4> |
| * Implementations of these locale sensitive services are packaged using the |
| * <a href="../../../../technotes/guides/extensions/index.html">Java Extension Mechanism</a> |
| * as installed extensions. A provider identifies itself with a |
| * provider-configuration file in the resource directory META-INF/services, |
| * using the fully qualified provider interface class name as the file name. |
| * The file should contain a list of fully-qualified concrete provider class names, |
| * one per line. A line is terminated by any one of a line feed ('\n'), a carriage |
| * return ('\r'), or a carriage return followed immediately by a line feed. Space |
| * and tab characters surrounding each name, as well as blank lines, are ignored. |
| * The comment character is '#' ('\u0023'); on each line all characters following |
| * the first comment character are ignored. The file must be encoded in UTF-8. |
| * <p> |
| * If a particular concrete provider class is named in more than one configuration |
| * file, or is named in the same configuration file more than once, then the |
| * duplicates will be ignored. The configuration file naming a particular provider |
| * need not be in the same jar file or other distribution unit as the provider itself. |
| * The provider must be accessible from the same class loader that was initially |
| * queried to locate the configuration file; this is not necessarily the class loader |
| * that loaded the file. |
| * <p> |
| * For example, an implementation of the |
| * {@link java.text.spi.DateFormatProvider DateFormatProvider} class should |
| * take the form of a jar file which contains the file: |
| * <pre> |
| * META-INF/services/java.text.spi.DateFormatProvider |
| * </pre> |
| * And the file <code>java.text.spi.DateFormatProvider</code> should have |
| * a line such as: |
| * <pre> |
| * <code>com.foo.DateFormatProviderImpl</code> |
| * </pre> |
| * which is the fully qualified class name of the class implementing |
| * <code>DateFormatProvider</code>. |
| * <h4>Invocation of Locale Sensitive Services</h4> |
| * <p> |
| * Locale sensitive factory methods and methods for name retrieval in the |
| * <code>java.text</code> and <code>java.util</code> packages invoke |
| * service provider methods when needed to support the requested locale. |
| * The methods first check whether the Java runtime environment itself |
| * supports the requested locale, and use its support if available. |
| * Otherwise, they call the <code>getAvailableLocales()</code> methods of |
| * installed providers for the appropriate interface to find one that |
| * supports the requested locale. If such a provider is found, its other |
| * methods are called to obtain the requested object or name. When checking |
| * whether a locale is supported, the locale's extensions are ignored. |
| * If neither the Java runtime environment itself nor an installed provider |
| * supports the requested locale, the methods go through a list of candidate |
| * locales and repeat the availability check for each until a match is found. |
| * The algorithm used for creating a list of candidate locales is same as |
| * the one used by <code>ResourceBunlde</code> by default (see |
| * {@link java.util.ResourceBundle.Control#getCandidateLocales getCandidateLocales} |
| * for the details). Even if a locale is resolved from the candidate list, |
| * methods that return requested objects or names are invoked with the original |
| * requested locale including extensions. The Java runtime environment must |
| * support the root locale for all locale sensitive services in order to |
| * guarantee that this process terminates. |
| * <p> |
| * Providers of names (but not providers of other objects) are allowed to |
| * return null for some name requests even for locales that they claim to |
| * support by including them in their return value for |
| * <code>getAvailableLocales</code>. Similarly, the Java runtime |
| * environment itself may not have all names for all locales that it |
| * supports. This is because the sets of objects for which names are |
| * requested can be large and vary over time, so that it's not always |
| * feasible to cover them completely. If the Java runtime environment or a |
| * provider returns null instead of a name, the lookup will proceed as |
| * described above as if the locale was not supported. |
| * |
| * @since 1.6 |
| */ |
| public abstract class LocaleServiceProvider { |
| |
| /** |
| * Sole constructor. (For invocation by subclass constructors, typically |
| * implicit.) |
| */ |
| protected LocaleServiceProvider() { |
| } |
| |
| /** |
| * Returns an array of all locales for which this locale service provider |
| * can provide localized objects or names. |
| * <p> |
| * <b>Note:</b> Extensions in a <code>Locale</code> are ignored during |
| * service provider lookup. So the array returned by this method should |
| * not include two or more <code>Locale</code> objects only differing in |
| * their extensions. |
| * |
| * @return An array of all locales for which this locale service provider |
| * can provide localized objects or names. |
| */ |
| public abstract Locale[] getAvailableLocales(); |
| } |