src/java.base/share/classes/sun/util/locale/LocaleExtensions.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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/*
 *******************************************************************************
 * Copyright (C) 2009-2010, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */
package sun.util.locale;

import java.util.Collections;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;

import sun.util.locale.InternalLocaleBuilder.CaseInsensitiveChar;
import sun.util.locale.InternalLocaleBuilder.CaseInsensitiveString;


public class LocaleExtensions {

    private final Map<Character, Extension> extensionMap;
    private final String id;

    public static final LocaleExtensions CALENDAR_JAPANESE
        = new LocaleExtensions("u-ca-japanese",
                               UnicodeLocaleExtension.SINGLETON,
                               UnicodeLocaleExtension.CA_JAPANESE);

    public static final LocaleExtensions NUMBER_THAI
        = new LocaleExtensions("u-nu-thai",
                               UnicodeLocaleExtension.SINGLETON,
                               UnicodeLocaleExtension.NU_THAI);

    private LocaleExtensions(String id, Character key, Extension value) {
        this.id = id;
        this.extensionMap = Collections.singletonMap(key, value);
    }

    /*
     * Package private constructor, only used by InternalLocaleBuilder.
     */
    LocaleExtensions(Map<CaseInsensitiveChar, String> extensions,
                     Set<CaseInsensitiveString> uattributes,
                     Map<CaseInsensitiveString, String> ukeywords) {
        boolean hasExtension = !LocaleUtils.isEmpty(extensions);
        boolean hasUAttributes = !LocaleUtils.isEmpty(uattributes);
        boolean hasUKeywords = !LocaleUtils.isEmpty(ukeywords);

        if (!hasExtension && !hasUAttributes && !hasUKeywords) {
            id = "";
            extensionMap = Collections.emptyMap();
            return;
        }

        // Build extension map
        SortedMap<Character, Extension> map = new TreeMap<>();
        if (hasExtension) {
            for (Entry<CaseInsensitiveChar, String> ext : extensions.entrySet()) {
                char key = LocaleUtils.toLower(ext.getKey().value());
                String value = ext.getValue();

                if (LanguageTag.isPrivateusePrefixChar(key)) {
                    // we need to exclude special variant in privuateuse, e.g. "x-abc-lvariant-DEF"
                    value = InternalLocaleBuilder.removePrivateuseVariant(value);
                    if (value == null) {
                        continue;
                    }
                }

                map.put(key, new Extension(key, LocaleUtils.toLowerString(value)));
            }
        }

        if (hasUAttributes || hasUKeywords) {
            SortedSet<String> uaset = null;
            SortedMap<String, String> ukmap = null;

            if (hasUAttributes) {
                uaset = new TreeSet<>();
                for (CaseInsensitiveString cis : uattributes) {
                    uaset.add(LocaleUtils.toLowerString(cis.value()));
                }
            }

            if (hasUKeywords) {
                ukmap = new TreeMap<>();
                for (Entry<CaseInsensitiveString, String> kwd : ukeywords.entrySet()) {
                    String key = LocaleUtils.toLowerString(kwd.getKey().value());
                    String type = LocaleUtils.toLowerString(kwd.getValue());
                    ukmap.put(key, type);
                }
            }

            UnicodeLocaleExtension ule = new UnicodeLocaleExtension(uaset, ukmap);
            map.put(UnicodeLocaleExtension.SINGLETON, ule);
        }

        if (map.isEmpty()) {
            // this could happen when only privuateuse with special variant
            id = "";
            extensionMap = Collections.emptyMap();
        } else {
            id = toID(map);
            extensionMap = map;
        }
    }

    public Set<Character> getKeys() {
        if (extensionMap.isEmpty()) {
            return Collections.emptySet();
        }
        return Collections.unmodifiableSet(extensionMap.keySet());
    }

    public Extension getExtension(Character key) {
        return extensionMap.get(LocaleUtils.toLower(key));
    }

    public String getExtensionValue(Character key) {
        Extension ext = extensionMap.get(LocaleUtils.toLower(key));
        if (ext == null) {
            return null;
        }
        return ext.getValue();
    }

    public Set<String> getUnicodeLocaleAttributes() {
        Extension ext = extensionMap.get(UnicodeLocaleExtension.SINGLETON);
        if (ext == null) {
            return Collections.emptySet();
        }
        assert (ext instanceof UnicodeLocaleExtension);
        return ((UnicodeLocaleExtension)ext).getUnicodeLocaleAttributes();
    }

    public Set<String> getUnicodeLocaleKeys() {
        Extension ext = extensionMap.get(UnicodeLocaleExtension.SINGLETON);
        if (ext == null) {
            return Collections.emptySet();
        }
        assert (ext instanceof UnicodeLocaleExtension);
        return ((UnicodeLocaleExtension)ext).getUnicodeLocaleKeys();
    }

    public String getUnicodeLocaleType(String unicodeLocaleKey) {
        Extension ext = extensionMap.get(UnicodeLocaleExtension.SINGLETON);
        if (ext == null) {
            return null;
        }
        assert (ext instanceof UnicodeLocaleExtension);
        return ((UnicodeLocaleExtension)ext).getUnicodeLocaleType(LocaleUtils.toLowerString(unicodeLocaleKey));
    }

    public boolean isEmpty() {
        return extensionMap.isEmpty();
    }

    public static boolean isValidKey(char c) {
        return LanguageTag.isExtensionSingletonChar(c) || LanguageTag.isPrivateusePrefixChar(c);
    }

    public static boolean isValidUnicodeLocaleKey(String ukey) {
        return UnicodeLocaleExtension.isKey(ukey);
    }

    private static String toID(SortedMap<Character, Extension> map) {
        StringBuilder buf = new StringBuilder();
        Extension privuse = null;
        for (Entry<Character, Extension> entry : map.entrySet()) {
            char singleton = entry.getKey();
            Extension extension = entry.getValue();
            if (LanguageTag.isPrivateusePrefixChar(singleton)) {
                privuse = extension;
            } else {
                if (buf.length() > 0) {
                    buf.append(LanguageTag.SEP);
                }
                buf.append(extension);
            }
        }
        if (privuse != null) {
            if (buf.length() > 0) {
                buf.append(LanguageTag.SEP);
            }
            buf.append(privuse);
        }
        return buf.toString();
    }

    @Override
    public String toString() {
        return id;
    }

    public String getID() {
        return id;
    }

    @Override
    public int hashCode() {
        return id.hashCode();
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof LocaleExtensions)) {
            return false;
        }
        return id.equals(((LocaleExtensions)other).id);
    }
}