--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/util/spi/LocaleServiceProvider.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,201 @@
+/*
+ * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * 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.
+ *
+ * This code 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
+ * 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
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+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.
+ *
+ * <h3>Packaging of Locale Sensitive Service Provider Implementations</h3>
+ * 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 {@link #isSupportedLocale(Locale) isSupportedLocale}
+ * 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 <a href="../Locale.html#def_extensions">
+ * locale's extensions</a> are ignored by default. (If locale's extensions should
+ * also be checked, the {@code isSupportedLocale} method must be overridden.)
+ * 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>ResourceBundle</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 {@code Locale} 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.
+ * <p>
+ * Starting from JDK8, the search order of locale sensitive services can
+ * be configured by using the "java.locale.providers" system property.
+ * This system property declares the user's preferred order for looking up
+ * the locale sensitive services separated by a comma. It is only read at
+ * the Java runtime startup, so the later call to System.setProperty() won't
+ * affect the order.
+ * <p>
+ * For example, if the following is specified in the property:
+ * <pre>
+ * java.locale.providers=SPI,JRE
+ * </pre>
+ * where "SPI" represents the locale sensitive services implemented in the
+ * installed SPI providers, and "JRE" represents the locale sensitive services
+ * in the Java Runtime Environment, the locale sensitive services in the SPI
+ * providers are looked up first.
+ * <p>
+ * There are two other possible locale sensitive service providers, i.e., "CLDR"
+ * which is a provider based on Unicode Consortium's
+ * <a href="http://cldr.unicode.org/">CLDR Project</a>, and "HOST" which is a
+ * provider that reflects the user's custom settings in the underlying operating
+ * system. These two providers may not be available, depending on the Java Runtime
+ * Environment implementation. Specifying "JRE,SPI" is identical to the default
+ * behavior, which is compatibile with the prior releases.
+ *
+ * @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. This information is used to
+ * compose {@code getAvailableLocales()} values of the locale-dependent
+ * services, such as {@code DateFormat.getAvailableLocales()}.
+ *
+ * <p>The array returned by this method should not include two or more
+ * {@code Locale} 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();
+
+ /**
+ * Returns {@code true} if the given {@code locale} is supported by
+ * this locale service provider. The given {@code locale} may contain
+ * <a href="../Locale.html#def_extensions">extensions</a> that should be
+ * taken into account for the support determination.
+ *
+ * <p>The default implementation returns {@code true} if the given {@code locale}
+ * is equal to any of the available {@code Locale}s returned by
+ * {@link #getAvailableLocales()} with ignoring any extensions in both the
+ * given {@code locale} and the available locales. Concrete locale service
+ * provider implementations should override this method if those
+ * implementations are {@code Locale} extensions-aware. For example,
+ * {@code DecimalFormatSymbolsProvider} implementations will need to check
+ * extensions in the given {@code locale} to see if any numbering system is
+ * specified and can be supported. However, {@code CollatorProvider}
+ * implementations may not be affected by any particular numbering systems,
+ * and in that case, extensions for numbering systems should be ignored.
+ *
+ * @param locale a {@code Locale} to be tested
+ * @return {@code true} if the given {@code locale} is supported by this
+ * provider; {@code false} otherwise.
+ * @throws NullPointerException
+ * if the given {@code locale} is {@code null}
+ * @see Locale#hasExtensions()
+ * @see Locale#stripExtensions()
+ * @since 1.8
+ */
+ public boolean isSupportedLocale(Locale locale) {
+ locale = locale.stripExtensions(); // throws NPE if locale == null
+ for (Locale available : getAvailableLocales()) {
+ if (locale.equals(available.stripExtensions())) {
+ return true;
+}
+ }
+ return false;
+ }
+}