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1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.  Oracle designates this
9  * particular file as subject to the "Classpath" exception as provided
10  * by Oracle in the LICENSE file that accompanied this code.
11  *
12  * This code is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  * version 2 for more details (a copy is included in the LICENSE file that
16  * accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License version
19  * 2 along with this work; if not, write to the Free Software Foundation,
20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21  *
22  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23  * or visit www.oracle.com if you need additional information or have any
24  * questions.
25  */
26 
27 /*
28  * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
29  * (C) Copyright IBM Corp. 1996 - All Rights Reserved
30  *
31  *   The original version of this source code and documentation is copyrighted
32  * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
33  * materials are provided under terms of a License Agreement between Taligent
34  * and Sun. This technology is protected by multiple US and International
35  * patents. This notice and attribution to Taligent may not be removed.
36  *   Taligent is a registered trademark of Taligent, Inc.
37  *
38  */
39 
40 package java.util;
41 
42 import org.apache.harmony.luni.internal.util.TimezoneGetter;
43 import android.icu.text.TimeZoneNames;
44 import java.io.IOException;
45 import java.io.Serializable;
46 import java.time.ZoneId;
47 import java.util.regex.Matcher;
48 import java.util.regex.Pattern;
49 import libcore.io.IoUtils;
50 import libcore.util.ZoneInfoDB;
51 
52 /**
53  * <code>TimeZone</code> represents a time zone offset, and also figures out daylight
54  * savings.
55  *
56  * <p>
57  * Typically, you get a <code>TimeZone</code> using <code>getDefault</code>
58  * which creates a <code>TimeZone</code> based on the time zone where the program
59  * is running. For example, for a program running in Japan, <code>getDefault</code>
60  * creates a <code>TimeZone</code> object based on Japanese Standard Time.
61  *
62  * <p>
63  * You can also get a <code>TimeZone</code> using <code>getTimeZone</code>
64  * along with a time zone ID. For instance, the time zone ID for the
65  * U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a
66  * U.S. Pacific Time <code>TimeZone</code> object with:
67  * <blockquote><pre>
68  * TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
69  * </pre></blockquote>
70  * You can use the <code>getAvailableIDs</code> method to iterate through
71  * all the supported time zone IDs. You can then choose a
72  * supported ID to get a <code>TimeZone</code>.
73  * If the time zone you want is not represented by one of the
74  * supported IDs, then a custom time zone ID can be specified to
75  * produce a TimeZone. The syntax of a custom time zone ID is:
76  *
77  * <blockquote><pre>
78  * <a name="CustomID"><i>CustomID:</i></a>
79  *         <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i>
80  *         <code>GMT</code> <i>Sign</i> <i>Hours</i> <i>Minutes</i>
81  *         <code>GMT</code> <i>Sign</i> <i>Hours</i>
82  * <i>Sign:</i> one of
83  *         <code>+ -</code>
84  * <i>Hours:</i>
85  *         <i>Digit</i>
86  *         <i>Digit</i> <i>Digit</i>
87  * <i>Minutes:</i>
88  *         <i>Digit</i> <i>Digit</i>
89  * <i>Digit:</i> one of
90  *         <code>0 1 2 3 4 5 6 7 8 9</code>
91  * </pre></blockquote>
92  *
93  * <i>Hours</i> must be between 0 to 23 and <i>Minutes</i> must be
94  * between 00 to 59.  For example, "GMT+10" and "GMT+0010" mean ten
95  * hours and ten minutes ahead of GMT, respectively.
96  * <p>
97  * The format is locale independent and digits must be taken from the
98  * Basic Latin block of the Unicode standard. No daylight saving time
99  * transition schedule can be specified with a custom time zone ID. If
100  * the specified string doesn't match the syntax, <code>"GMT"</code>
101  * is used.
102  * <p>
103  * When creating a <code>TimeZone</code>, the specified custom time
104  * zone ID is normalized in the following syntax:
105  * <blockquote><pre>
106  * <a name="NormalizedCustomID"><i>NormalizedCustomID:</i></a>
107  *         <code>GMT</code> <i>Sign</i> <i>TwoDigitHours</i> <code>:</code> <i>Minutes</i>
108  * <i>Sign:</i> one of
109  *         <code>+ -</code>
110  * <i>TwoDigitHours:</i>
111  *         <i>Digit</i> <i>Digit</i>
112  * <i>Minutes:</i>
113  *         <i>Digit</i> <i>Digit</i>
114  * <i>Digit:</i> one of
115  *         <code>0 1 2 3 4 5 6 7 8 9</code>
116  * </pre></blockquote>
117  * For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00".
118  *
119  * <h3>Three-letter time zone IDs</h3>
120  *
121  * For compatibility with JDK 1.1.x, some other three-letter time zone IDs
122  * (such as "PST", "CTT", "AST") are also supported. However, <strong>their
123  * use is deprecated</strong> because the same abbreviation is often used
124  * for multiple time zones (for example, "CST" could be U.S. "Central Standard
125  * Time" and "China Standard Time"), and the Java platform can then only
126  * recognize one of them.
127  *
128  *
129  * @see          Calendar
130  * @see          GregorianCalendar
131  * @see          SimpleTimeZone
132  * @author       Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
133  * @since        JDK1.1
134  */
135 abstract public class TimeZone implements Serializable, Cloneable {
136     /**
137      * Sole constructor.  (For invocation by subclass constructors, typically
138      * implicit.)
139      */
TimeZone()140     public TimeZone() {
141     }
142 
143     /**
144      * A style specifier for <code>getDisplayName()</code> indicating
145      * a short name, such as "PST."
146      * @see #LONG
147      * @since 1.2
148      */
149     public static final int SHORT = 0;
150 
151     /**
152      * A style specifier for <code>getDisplayName()</code> indicating
153      * a long name, such as "Pacific Standard Time."
154      * @see #SHORT
155      * @since 1.2
156      */
157     public static final int LONG  = 1;
158 
159     // Android-changed: Use a preload holder to allow compile-time initialization of TimeZone and
160     // dependents.
161     private static class NoImagePreloadHolder {
162         public static final Pattern CUSTOM_ZONE_ID_PATTERN = Pattern.compile("^GMT[-+](\\d{1,2})(:?(\\d\\d))?$");
163     }
164 
165     // Proclaim serialization compatibility with JDK 1.1
166     static final long serialVersionUID = 3581463369166924961L;
167 
168     // Android-changed: common timezone instances.
169     private static final TimeZone GMT = new SimpleTimeZone(0, "GMT");
170     private static final TimeZone UTC = new SimpleTimeZone(0, "UTC");
171 
172     /**
173      * Gets the time zone offset, for current date, modified in case of
174      * daylight savings. This is the offset to add to UTC to get local time.
175      * <p>
176      * This method returns a historically correct offset if an
177      * underlying <code>TimeZone</code> implementation subclass
178      * supports historical Daylight Saving Time schedule and GMT
179      * offset changes.
180      *
181      * @param era the era of the given date.
182      * @param year the year in the given date.
183      * @param month the month in the given date.
184      * Month is 0-based. e.g., 0 for January.
185      * @param day the day-in-month of the given date.
186      * @param dayOfWeek the day-of-week of the given date.
187      * @param milliseconds the milliseconds in day in <em>standard</em>
188      * local time.
189      *
190      * @return the offset in milliseconds to add to GMT to get local time.
191      *
192      * @see Calendar#ZONE_OFFSET
193      * @see Calendar#DST_OFFSET
194      */
getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds)195     public abstract int getOffset(int era, int year, int month, int day,
196                                   int dayOfWeek, int milliseconds);
197 
198     /**
199      * Returns the offset of this time zone from UTC at the specified
200      * date. If Daylight Saving Time is in effect at the specified
201      * date, the offset value is adjusted with the amount of daylight
202      * saving.
203      * <p>
204      * This method returns a historically correct offset value if an
205      * underlying TimeZone implementation subclass supports historical
206      * Daylight Saving Time schedule and GMT offset changes.
207      *
208      * @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT
209      * @return the amount of time in milliseconds to add to UTC to get local time.
210      *
211      * @see Calendar#ZONE_OFFSET
212      * @see Calendar#DST_OFFSET
213      * @since 1.4
214      */
getOffset(long date)215     public int getOffset(long date) {
216         if (inDaylightTime(new Date(date))) {
217             return getRawOffset() + getDSTSavings();
218         }
219         return getRawOffset();
220     }
221 
222     /**
223      * Gets the raw GMT offset and the amount of daylight saving of this
224      * time zone at the given time.
225      * @param date the milliseconds (since January 1, 1970,
226      * 00:00:00.000 GMT) at which the time zone offset and daylight
227      * saving amount are found
228      * @param offsets an array of int where the raw GMT offset
229      * (offset[0]) and daylight saving amount (offset[1]) are stored,
230      * or null if those values are not needed. The method assumes that
231      * the length of the given array is two or larger.
232      * @return the total amount of the raw GMT offset and daylight
233      * saving at the specified date.
234      *
235      * @see Calendar#ZONE_OFFSET
236      * @see Calendar#DST_OFFSET
237      */
getOffsets(long date, int[] offsets)238     int getOffsets(long date, int[] offsets) {
239         int rawoffset = getRawOffset();
240         int dstoffset = 0;
241         if (inDaylightTime(new Date(date))) {
242             dstoffset = getDSTSavings();
243         }
244         if (offsets != null) {
245             offsets[0] = rawoffset;
246             offsets[1] = dstoffset;
247         }
248         return rawoffset + dstoffset;
249     }
250 
251     /**
252      * Sets the base time zone offset to GMT.
253      * This is the offset to add to UTC to get local time.
254      * <p>
255      * If an underlying <code>TimeZone</code> implementation subclass
256      * supports historical GMT offset changes, the specified GMT
257      * offset is set as the latest GMT offset and the difference from
258      * the known latest GMT offset value is used to adjust all
259      * historical GMT offset values.
260      *
261      * @param offsetMillis the given base time zone offset to GMT.
262      */
setRawOffset(int offsetMillis)263     abstract public void setRawOffset(int offsetMillis);
264 
265     /**
266      * Returns the amount of time in milliseconds to add to UTC to get
267      * standard time in this time zone. Because this value is not
268      * affected by daylight saving time, it is called <I>raw
269      * offset</I>.
270      * <p>
271      * If an underlying <code>TimeZone</code> implementation subclass
272      * supports historical GMT offset changes, the method returns the
273      * raw offset value of the current date. In Honolulu, for example,
274      * its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and
275      * this method always returns -36000000 milliseconds (i.e., -10
276      * hours).
277      *
278      * @return the amount of raw offset time in milliseconds to add to UTC.
279      * @see Calendar#ZONE_OFFSET
280      */
getRawOffset()281     public abstract int getRawOffset();
282 
283     /**
284      * Gets the ID of this time zone.
285      * @return the ID of this time zone.
286      */
getID()287     public String getID()
288     {
289         return ID;
290     }
291 
292     /**
293      * Sets the time zone ID. This does not change any other data in
294      * the time zone object.
295      * @param ID the new time zone ID.
296      */
setID(String ID)297     public void setID(String ID)
298     {
299         if (ID == null) {
300             throw new NullPointerException();
301         }
302         this.ID = ID;
303     }
304 
305     /**
306      * Returns a long standard time name of this {@code TimeZone} suitable for
307      * presentation to the user in the default locale.
308      *
309      * <p>This method is equivalent to:
310      * <blockquote><pre>
311      * getDisplayName(false, {@link #LONG},
312      *                Locale.getDefault({@link Locale.Category#DISPLAY}))
313      * </pre></blockquote>
314      *
315      * @return the human-readable name of this time zone in the default locale.
316      * @since 1.2
317      * @see #getDisplayName(boolean, int, Locale)
318      * @see Locale#getDefault(Locale.Category)
319      * @see Locale.Category
320      */
getDisplayName()321     public final String getDisplayName() {
322         return getDisplayName(false, LONG,
323                               Locale.getDefault(Locale.Category.DISPLAY));
324     }
325 
326     /**
327      * Returns a long standard time name of this {@code TimeZone} suitable for
328      * presentation to the user in the specified {@code locale}.
329      *
330      * <p>This method is equivalent to:
331      * <blockquote><pre>
332      * getDisplayName(false, {@link #LONG}, locale)
333      * </pre></blockquote>
334      *
335      * @param locale the locale in which to supply the display name.
336      * @return the human-readable name of this time zone in the given locale.
337      * @exception NullPointerException if {@code locale} is {@code null}.
338      * @since 1.2
339      * @see #getDisplayName(boolean, int, Locale)
340      */
getDisplayName(Locale locale)341     public final String getDisplayName(Locale locale) {
342         return getDisplayName(false, LONG, locale);
343     }
344 
345     /**
346      * Returns a name in the specified {@code style} of this {@code TimeZone}
347      * suitable for presentation to the user in the default locale. If the
348      * specified {@code daylight} is {@code true}, a Daylight Saving Time name
349      * is returned (even if this {@code TimeZone} doesn't observe Daylight Saving
350      * Time). Otherwise, a Standard Time name is returned.
351      *
352      * <p>This method is equivalent to:
353      * <blockquote><pre>
354      * getDisplayName(daylight, style,
355      *                Locale.getDefault({@link Locale.Category#DISPLAY}))
356      * </pre></blockquote>
357      *
358      * @param daylight {@code true} specifying a Daylight Saving Time name, or
359      *                 {@code false} specifying a Standard Time name
360      * @param style either {@link #LONG} or {@link #SHORT}
361      * @return the human-readable name of this time zone in the default locale.
362      * @exception IllegalArgumentException if {@code style} is invalid.
363      * @since 1.2
364      * @see #getDisplayName(boolean, int, Locale)
365      * @see Locale#getDefault(Locale.Category)
366      * @see Locale.Category
367      * @see java.text.DateFormatSymbols#getZoneStrings()
368      */
getDisplayName(boolean daylight, int style)369     public final String getDisplayName(boolean daylight, int style) {
370         return getDisplayName(daylight, style,
371                               Locale.getDefault(Locale.Category.DISPLAY));
372     }
373 
374     /**
375      * Returns the {@link #SHORT short} or {@link #LONG long} name of this time
376      * zone with either standard or daylight time, as written in {@code locale}.
377      * If the name is not available, the result is in the format
378      * {@code GMT[+-]hh:mm}.
379      *
380      * @param daylightTime true for daylight time, false for standard time.
381      * @param style either {@link TimeZone#LONG} or {@link TimeZone#SHORT}.
382      * @param locale the display locale.
383      */
getDisplayName(boolean daylightTime, int style, Locale locale)384     public String getDisplayName(boolean daylightTime, int style, Locale locale) {
385         // BEGIN Android-changed: implement using android.icu.text.TimeZoneNames
386         TimeZoneNames.NameType nameType;
387         switch (style) {
388             case SHORT:
389                 nameType = daylightTime
390                         ? TimeZoneNames.NameType.SHORT_DAYLIGHT
391                         : TimeZoneNames.NameType.SHORT_STANDARD;
392                 break;
393             case LONG:
394                 nameType = daylightTime
395                         ? TimeZoneNames.NameType.LONG_DAYLIGHT
396                         : TimeZoneNames.NameType.LONG_STANDARD;
397                 break;
398             default:
399                 throw new IllegalArgumentException("Illegal style: " + style);
400         }
401         String canonicalID = android.icu.util.TimeZone.getCanonicalID(getID());
402         if (canonicalID != null) {
403             TimeZoneNames names = TimeZoneNames.getInstance(locale);
404             long now = System.currentTimeMillis();
405             String displayName = names.getDisplayName(canonicalID, nameType, now);
406             if (displayName != null) {
407                 return displayName;
408             }
409         }
410 
411         // We get here if this is a custom timezone or ICU doesn't have name data for the specific
412         // style and locale.
413         int offsetMillis = getRawOffset();
414         if (daylightTime) {
415             offsetMillis += getDSTSavings();
416         }
417         return createGmtOffsetString(true /* includeGmt */, true /* includeMinuteSeparator */,
418                 offsetMillis);
419         // END Android-changed: implement using android.icu.text.TimeZoneNames
420     }
421 
422     // BEGIN Android-added: utility method to format an offset as a GMT offset string.
423     /**
424      * Returns a string representation of an offset from UTC.
425      *
426      * <p>The format is "[GMT](+|-)HH[:]MM". The output is not localized.
427      *
428      * @param includeGmt true to include "GMT", false to exclude
429      * @param includeMinuteSeparator true to include the separator between hours and minutes, false
430      *     to exclude.
431      * @param offsetMillis the offset from UTC
432      *
433      * @hide used internally by SimpleDateFormat
434      */
createGmtOffsetString(boolean includeGmt, boolean includeMinuteSeparator, int offsetMillis)435     public static String createGmtOffsetString(boolean includeGmt,
436             boolean includeMinuteSeparator, int offsetMillis) {
437         int offsetMinutes = offsetMillis / 60000;
438         char sign = '+';
439         if (offsetMinutes < 0) {
440             sign = '-';
441             offsetMinutes = -offsetMinutes;
442         }
443         StringBuilder builder = new StringBuilder(9);
444         if (includeGmt) {
445             builder.append("GMT");
446         }
447         builder.append(sign);
448         appendNumber(builder, 2, offsetMinutes / 60);
449         if (includeMinuteSeparator) {
450             builder.append(':');
451         }
452         appendNumber(builder, 2, offsetMinutes % 60);
453         return builder.toString();
454     }
455 
appendNumber(StringBuilder builder, int count, int value)456     private static void appendNumber(StringBuilder builder, int count, int value) {
457         String string = Integer.toString(value);
458         for (int i = 0; i < count - string.length(); i++) {
459             builder.append('0');
460         }
461         builder.append(string);
462     }
463     // END Android-added: utility method to format an offset as a GMT offset string.
464 
465     /**
466      * Returns the amount of time to be added to local standard time
467      * to get local wall clock time.
468      *
469      * <p>The default implementation returns 3600000 milliseconds
470      * (i.e., one hour) if a call to {@link #useDaylightTime()}
471      * returns {@code true}. Otherwise, 0 (zero) is returned.
472      *
473      * <p>If an underlying {@code TimeZone} implementation subclass
474      * supports historical and future Daylight Saving Time schedule
475      * changes, this method returns the amount of saving time of the
476      * last known Daylight Saving Time rule that can be a future
477      * prediction.
478      *
479      * <p>If the amount of saving time at any given time stamp is
480      * required, construct a {@link Calendar} with this {@code
481      * TimeZone} and the time stamp, and call {@link Calendar#get(int)
482      * Calendar.get}{@code (}{@link Calendar#DST_OFFSET}{@code )}.
483      *
484      * @return the amount of saving time in milliseconds
485      * @since 1.4
486      * @see #inDaylightTime(Date)
487      * @see #getOffset(long)
488      * @see #getOffset(int,int,int,int,int,int)
489      * @see Calendar#ZONE_OFFSET
490      */
getDSTSavings()491     public int getDSTSavings() {
492         if (useDaylightTime()) {
493             return 3600000;
494         }
495         return 0;
496     }
497 
498     /**
499      * Queries if this {@code TimeZone} uses Daylight Saving Time.
500      *
501      * <p>If an underlying {@code TimeZone} implementation subclass
502      * supports historical and future Daylight Saving Time schedule
503      * changes, this method refers to the last known Daylight Saving Time
504      * rule that can be a future prediction and may not be the same as
505      * the current rule. Consider calling {@link #observesDaylightTime()}
506      * if the current rule should also be taken into account.
507      *
508      * @return {@code true} if this {@code TimeZone} uses Daylight Saving Time,
509      *         {@code false}, otherwise.
510      * @see #inDaylightTime(Date)
511      * @see Calendar#DST_OFFSET
512      */
useDaylightTime()513     public abstract boolean useDaylightTime();
514 
515     /**
516      * Returns {@code true} if this {@code TimeZone} is currently in
517      * Daylight Saving Time, or if a transition from Standard Time to
518      * Daylight Saving Time occurs at any future time.
519      *
520      * <p>The default implementation returns {@code true} if
521      * {@code useDaylightTime()} or {@code inDaylightTime(new Date())}
522      * returns {@code true}.
523      *
524      * @return {@code true} if this {@code TimeZone} is currently in
525      * Daylight Saving Time, or if a transition from Standard Time to
526      * Daylight Saving Time occurs at any future time; {@code false}
527      * otherwise.
528      * @since 1.7
529      * @see #useDaylightTime()
530      * @see #inDaylightTime(Date)
531      * @see Calendar#DST_OFFSET
532      */
observesDaylightTime()533     public boolean observesDaylightTime() {
534         return useDaylightTime() || inDaylightTime(new Date());
535     }
536 
537     /**
538      * Queries if the given {@code date} is in Daylight Saving Time in
539      * this time zone.
540      *
541      * @param date the given Date.
542      * @return {@code true} if the given date is in Daylight Saving Time,
543      *         {@code false}, otherwise.
544      */
inDaylightTime(Date date)545     abstract public boolean inDaylightTime(Date date);
546 
547     /**
548      * Gets the <code>TimeZone</code> for the given ID.
549      *
550      * @param id the ID for a <code>TimeZone</code>, either an abbreviation
551      * such as "PST", a full name such as "America/Los_Angeles", or a custom
552      * ID such as "GMT-8:00". Note that the support of abbreviations is
553      * for JDK 1.1.x compatibility only and full names should be used.
554      *
555      * @return the specified <code>TimeZone</code>, or the GMT zone if the given ID
556      * cannot be understood.
557      */
558     // Android-changed: param s/ID/id; use ZoneInfoDB instead of ZoneInfo class.
getTimeZone(String id)559     public static synchronized TimeZone getTimeZone(String id) {
560         if (id == null) {
561             throw new NullPointerException("id == null");
562         }
563 
564         // Special cases? These can clone an existing instance.
565         if (id.length() == 3) {
566             if (id.equals("GMT")) {
567                 return (TimeZone) GMT.clone();
568             }
569             if (id.equals("UTC")) {
570                 return (TimeZone) UTC.clone();
571             }
572         }
573 
574         // In the database?
575         TimeZone zone = null;
576         try {
577             zone = ZoneInfoDB.getInstance().makeTimeZone(id);
578         } catch (IOException ignored) {
579         }
580 
581         // Custom time zone?
582         if (zone == null && id.length() > 3 && id.startsWith("GMT")) {
583             zone = getCustomTimeZone(id);
584         }
585 
586         // We never return null; on failure we return the equivalent of "GMT".
587         return (zone != null) ? zone : (TimeZone) GMT.clone();
588     }
589 
590     /**
591      * Gets the {@code TimeZone} for the given {@code zoneId}.
592      *
593      * @param zoneId a {@link ZoneId} from which the time zone ID is obtained
594      * @return the specified {@code TimeZone}, or the GMT zone if the given ID
595      *         cannot be understood.
596      * @throws NullPointerException if {@code zoneId} is {@code null}
597      * @since 1.8
598      */
getTimeZone(ZoneId zoneId)599     public static TimeZone getTimeZone(ZoneId zoneId) {
600         String tzid = zoneId.getId(); // throws an NPE if null
601         char c = tzid.charAt(0);
602         if (c == '+' || c == '-') {
603             tzid = "GMT" + tzid;
604         } else if (c == 'Z' && tzid.length() == 1) {
605             tzid = "UTC";
606         }
607         return getTimeZone(tzid);
608     }
609 
610     /**
611      * Converts this {@code TimeZone} object to a {@code ZoneId}.
612      *
613      * @return a {@code ZoneId} representing the same time zone as this
614      *         {@code TimeZone}
615      * @since 1.8
616      */
toZoneId()617     public ZoneId toZoneId() {
618         // Android-changed: don't support "old mapping"
619         return ZoneId.of(getID(), ZoneId.SHORT_IDS);
620     }
621 
622     /**
623      * Returns a new SimpleTimeZone for an ID of the form "GMT[+|-]hh[[:]mm]", or null.
624      */
getCustomTimeZone(String id)625     private static TimeZone getCustomTimeZone(String id) {
626         Matcher m = NoImagePreloadHolder.CUSTOM_ZONE_ID_PATTERN.matcher(id);
627         if (!m.matches()) {
628             return null;
629         }
630 
631         int hour;
632         int minute = 0;
633         try {
634             hour = Integer.parseInt(m.group(1));
635             if (m.group(3) != null) {
636                 minute = Integer.parseInt(m.group(3));
637             }
638         } catch (NumberFormatException impossible) {
639             throw new AssertionError(impossible);
640         }
641 
642         if (hour < 0 || hour > 23 || minute < 0 || minute > 59) {
643             return null;
644         }
645 
646         char sign = id.charAt(3);
647         int raw = (hour * 3600000) + (minute * 60000);
648         if (sign == '-') {
649             raw = -raw;
650         }
651 
652         String cleanId = String.format(Locale.ROOT, "GMT%c%02d:%02d", sign, hour, minute);
653 
654         return new SimpleTimeZone(raw, cleanId);
655     }
656 
657     /**
658      * Gets the available IDs according to the given time zone offset in milliseconds.
659      *
660      * @param rawOffset the given time zone GMT offset in milliseconds.
661      * @return an array of IDs, where the time zone for that ID has
662      * the specified GMT offset. For example, "America/Phoenix" and "America/Denver"
663      * both have GMT-07:00, but differ in daylight saving behavior.
664      * @see #getRawOffset()
665      */
getAvailableIDs(int rawOffset)666     public static synchronized String[] getAvailableIDs(int rawOffset) {
667         return ZoneInfoDB.getInstance().getAvailableIDs(rawOffset);
668     }
669 
670     /**
671      * Gets all the available IDs supported.
672      * @return an array of IDs.
673      */
getAvailableIDs()674     public static synchronized String[] getAvailableIDs() {
675         return ZoneInfoDB.getInstance().getAvailableIDs();
676     }
677 
678     /**
679      * Gets the platform defined TimeZone ID.
680      **/
getSystemTimeZoneID(String javaHome, String country)681     private static native String getSystemTimeZoneID(String javaHome,
682                                                      String country);
683 
684     /**
685      * Gets the custom time zone ID based on the GMT offset of the
686      * platform. (e.g., "GMT+08:00")
687      */
getSystemGMTOffsetID()688     private static native String getSystemGMTOffsetID();
689 
690     /**
691      * Gets the default <code>TimeZone</code> for this host.
692      * The source of the default <code>TimeZone</code>
693      * may vary with implementation.
694      * @return a default <code>TimeZone</code>.
695      * @see #setDefault
696      */
getDefault()697     public static TimeZone getDefault() {
698         return (TimeZone) getDefaultRef().clone();
699     }
700 
701     /**
702      * Returns the reference to the default TimeZone object. This
703      * method doesn't create a clone.
704      */
getDefaultRef()705     static synchronized TimeZone getDefaultRef() {
706         if (defaultTimeZone == null) {
707             TimezoneGetter tzGetter = TimezoneGetter.getInstance();
708             String zoneName = (tzGetter != null) ? tzGetter.getId() : null;
709             if (zoneName != null) {
710                 zoneName = zoneName.trim();
711             }
712             if (zoneName == null || zoneName.isEmpty()) {
713                 try {
714                     // On the host, we can find the configured timezone here.
715                     zoneName = IoUtils.readFileAsString("/etc/timezone");
716                 } catch (IOException ex) {
717                     // "vogar --mode device" can end up here.
718                     // TODO: give libcore access to Android system properties and read "persist.sys.timezone".
719                     zoneName = "GMT";
720                 }
721             }
722             defaultTimeZone = TimeZone.getTimeZone(zoneName);
723         }
724         return defaultTimeZone;
725     }
726 
727     /**
728      * Sets the {@code TimeZone} that is returned by the {@code getDefault}
729      * method. {@code timeZone} is cached. If {@code timeZone} is null, the cached
730      * default {@code TimeZone} is cleared. This method doesn't change the value
731      * of the {@code user.timezone} property.
732      *
733      * @param timeZone the new default {@code TimeZone}, or null
734      * @see #getDefault
735      */
736     // Android-changed: s/zone/timeZone, synchronized, removed mention of SecurityException
setDefault(TimeZone timeZone)737     public synchronized static void setDefault(TimeZone timeZone)
738     {
739         SecurityManager sm = System.getSecurityManager();
740         if (sm != null) {
741             sm.checkPermission(new PropertyPermission
742                     ("user.timezone", "write"));
743         }
744         defaultTimeZone = timeZone != null ? (TimeZone) timeZone.clone() : null;
745         // Android-changed: notify ICU4J of changed default TimeZone.
746         android.icu.util.TimeZone.clearCachedDefault();
747     }
748 
749     /**
750      * Returns true if this zone has the same rule and offset as another zone.
751      * That is, if this zone differs only in ID, if at all.  Returns false
752      * if the other zone is null.
753      * @param other the <code>TimeZone</code> object to be compared with
754      * @return true if the other zone is not null and is the same as this one,
755      * with the possible exception of the ID
756      * @since 1.2
757      */
hasSameRules(TimeZone other)758     public boolean hasSameRules(TimeZone other) {
759         return other != null && getRawOffset() == other.getRawOffset() &&
760             useDaylightTime() == other.useDaylightTime();
761     }
762 
763     /**
764      * Creates a copy of this <code>TimeZone</code>.
765      *
766      * @return a clone of this <code>TimeZone</code>
767      */
clone()768     public Object clone()
769     {
770         try {
771             TimeZone other = (TimeZone) super.clone();
772             other.ID = ID;
773             return other;
774         } catch (CloneNotSupportedException e) {
775             throw new InternalError(e);
776         }
777     }
778 
779     /**
780      * The null constant as a TimeZone.
781      */
782     static final TimeZone NO_TIMEZONE = null;
783 
784     // =======================privates===============================
785 
786     /**
787      * The string identifier of this <code>TimeZone</code>.  This is a
788      * programmatic identifier used internally to look up <code>TimeZone</code>
789      * objects from the system table and also to map them to their localized
790      * display names.  <code>ID</code> values are unique in the system
791      * table but may not be for dynamically created zones.
792      * @serial
793      */
794     private String           ID;
795     private static volatile TimeZone defaultTimeZone;
796 }
797