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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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/*

 * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 *  * Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *

 *  * Neither the name of JSR-310 nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

package java.time;

import java.io.DataInput;

import java.io.DataOutput;

import java.io.IOException;

import java.io.InvalidObjectException;

import java.io.ObjectInputStream;

import java.io.Serializable;

import java.time.zone.ZoneRules;

import java.time.zone.ZoneRulesException;

import java.time.zone.ZoneRulesProvider;

import java.util.Objects;

/**

 * A geographical region where the same time-zone rules apply.

 * <p>

 * Time-zone information is categorized as a set of rules defining when and

 * how the offset from UTC/Greenwich changes. These rules are accessed using

 * identifiers based on geographical regions, such as countries or states.

 * The most common region classification is the Time Zone Database (TZDB),

 * which defines regions such as 'Europe/Paris' and 'Asia/Tokyo'.

 * <p>

 * The region identifier, modeled by this class, is distinct from the

 * underlying rules, modeled by {@link ZoneRules}.

 * The rules are defined by governments and change frequently.

 * By contrast, the region identifier is well-defined and long-lived.

 * This separation also allows rules to be shared between regions if appropriate.

 *

 * @implSpec

 * This class is immutable and thread-safe.

 *

 * @since 1.8

 */

final class ZoneRegion extends ZoneId implements Serializable {

    /**

     * Serialization version.

     */

    private static final long serialVersionUID = 8386373296231747096L;

    /**

     * The time-zone ID, not null.

     */

    private final String id;

    /**

     * The time-zone rules, null if zone ID was loaded leniently.

     */

    private final transient ZoneRules rules;

    /**

     * Obtains an instance of {@code ZoneId} from an identifier.

     *

     * @param zoneId  the time-zone ID, not null

     * @param checkAvailable  whether to check if the zone ID is available

     * @return the zone ID, not null

     * @throws DateTimeException if the ID format is invalid

     * @throws ZoneRulesException if checking availability and the ID cannot be found

     */

    static ZoneRegion ofId(String zoneId, boolean checkAvailable) {

        Objects.requireNonNull(zoneId, "zoneId");

        checkName(zoneId);

        ZoneRules rules = null;

        try {

            // always attempt load for better behavior after deserialization

            rules = ZoneRulesProvider.getRules(zoneId, true);

        } catch (ZoneRulesException ex) {

            if (checkAvailable) {

                throw ex;

            }

        }

        return new ZoneRegion(zoneId, rules);

    }

    /**

     * Checks that the given string is a legal ZondId name.

     *

     * @param zoneId  the time-zone ID, not null

     * @throws DateTimeException if the ID format is invalid

     */

    private static void checkName(String zoneId) {

        int n = zoneId.length();

        if (n < 2) {

           throw new DateTimeException("Invalid ID for region-based ZoneId, invalid format: " + zoneId);

        }

        for (int i = 0; i < n; i++) {

            char c = zoneId.charAt(i);

            if (c >= 'a' && c <= 'z') continue;

            if (c >= 'A' && c <= 'Z') continue;

            if (c == '/' && i != 0) continue;

            if (c >= '0' && c <= '9' && i != 0) continue;

            if (c == '~' && i != 0) continue;

            if (c == '.' && i != 0) continue;

            if (c == '_' && i != 0) continue;

            if (c == '+' && i != 0) continue;

            if (c == '-' && i != 0) continue;

            throw new DateTimeException("Invalid ID for region-based ZoneId, invalid format: " + zoneId);

        }

    }

    //-------------------------------------------------------------------------

    /**

     * Constructor.

     *

     * @param id  the time-zone ID, not null

     * @param rules  the rules, null for lazy lookup

     */

    ZoneRegion(String id, ZoneRules rules) {

        this.id = id;

        this.rules = rules;

    }

    //-----------------------------------------------------------------------

    @Override

    public String getId() {

        return id;

    }

    @Override

    public ZoneRules getRules() {

        // additional query for group provider when null allows for possibility

        // that the provider was updated after the ZoneId was created

        return (rules != null ? rules : ZoneRulesProvider.getRules(id, false));

    }

    //-----------------------------------------------------------------------

    /**

     * Writes the object using a

     * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.

     * @serialData

     * <pre>

     *  out.writeByte(7);  // identifies a ZoneId (not ZoneOffset)

     *  out.writeUTF(zoneId);

     * </pre>

     *

     * @return the instance of {@code Ser}, not null

     */

    private Object writeReplace() {

        return new Ser(Ser.ZONE_REGION_TYPE, this);

    }

    /**

     * Defend against malicious streams.

     *

     * @param s the stream to read

     * @throws InvalidObjectException always

     */

    private void readObject(ObjectInputStream s) throws InvalidObjectException {

        throw new InvalidObjectException("Deserialization via serialization delegate");

    }

    @Override

    void write(DataOutput out) throws IOException {

        out.writeByte(Ser.ZONE_REGION_TYPE);

        writeExternal(out);

    }

    void writeExternal(DataOutput out) throws IOException {

        out.writeUTF(id);

    }

    static ZoneId readExternal(DataInput in) throws IOException {

        String id = in.readUTF();

        return ZoneId.of(id, false);

    }

}