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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 android.icu.text.TimeZoneNames;
43 import com.android.i18n.timezone.ZoneInfoData;
44 import com.android.i18n.timezone.ZoneInfoDb;
45 import com.android.icu.util.ExtendedTimeZone;
46 
47 import java.io.IOException;
48 import java.io.Serializable;
49 import java.time.ZoneId;
50 import java.util.function.Supplier;
51 import java.util.regex.Matcher;
52 import java.util.regex.Pattern;
53 import libcore.io.IoUtils;
54 import libcore.util.ZoneInfo;
55 
56 import dalvik.system.RuntimeHooks;
57 
58 /**
59  * <code>TimeZone</code> represents a time zone offset, and also figures out daylight
60  * savings.
61  *
62  * <p>
63  * Typically, you get a <code>TimeZone</code> using <code>getDefault</code>
64  * which creates a <code>TimeZone</code> based on the time zone where the program
65  * is running. For example, for a program running in Japan, <code>getDefault</code>
66  * creates a <code>TimeZone</code> object based on Japanese Standard Time.
67  *
68  * <p>
69  * You can also get a <code>TimeZone</code> using <code>getTimeZone</code>
70  * along with a time zone ID. For instance, the time zone ID for the
71  * U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a
72  * U.S. Pacific Time <code>TimeZone</code> object with:
73  * <blockquote><pre>
74  * TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
75  * </pre></blockquote>
76  * You can use the <code>getAvailableIDs</code> method to iterate through
77  * all the supported time zone IDs. You can then choose a
78  * supported ID to get a <code>TimeZone</code>.
79  * If the time zone you want is not represented by one of the
80  * supported IDs, then a custom time zone ID can be specified to
81  * produce a TimeZone. The syntax of a custom time zone ID is:
82  *
83  * <blockquote><pre>
84  * <a name="CustomID"><i>CustomID:</i></a>
85  *         <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i>
86  *         <code>GMT</code> <i>Sign</i> <i>Hours</i> <i>Minutes</i>
87  *         <code>GMT</code> <i>Sign</i> <i>Hours</i>
88  * <i>Sign:</i> one of
89  *         <code>+ -</code>
90  * <i>Hours:</i>
91  *         <i>Digit</i>
92  *         <i>Digit</i> <i>Digit</i>
93  * <i>Minutes:</i>
94  *         <i>Digit</i> <i>Digit</i>
95  * <i>Digit:</i> one of
96  *         <code>0 1 2 3 4 5 6 7 8 9</code>
97  * </pre></blockquote>
98  *
99  * <i>Hours</i> must be between 0 to 23 and <i>Minutes</i> must be
100  * between 00 to 59.  For example, "GMT+10" and "GMT+0010" mean ten
101  * hours and ten minutes ahead of GMT, respectively.
102  * <p>
103  * The format is locale independent and digits must be taken from the
104  * Basic Latin block of the Unicode standard. No daylight saving time
105  * transition schedule can be specified with a custom time zone ID. If
106  * the specified string doesn't match the syntax, <code>"GMT"</code>
107  * is used.
108  * <p>
109  * When creating a <code>TimeZone</code>, the specified custom time
110  * zone ID is normalized in the following syntax:
111  * <blockquote><pre>
112  * <a name="NormalizedCustomID"><i>NormalizedCustomID:</i></a>
113  *         <code>GMT</code> <i>Sign</i> <i>TwoDigitHours</i> <code>:</code> <i>Minutes</i>
114  * <i>Sign:</i> one of
115  *         <code>+ -</code>
116  * <i>TwoDigitHours:</i>
117  *         <i>Digit</i> <i>Digit</i>
118  * <i>Minutes:</i>
119  *         <i>Digit</i> <i>Digit</i>
120  * <i>Digit:</i> one of
121  *         <code>0 1 2 3 4 5 6 7 8 9</code>
122  * </pre></blockquote>
123  * For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00".
124  *
125  * <h3>Three-letter time zone IDs</h3>
126  *
127  * For compatibility with JDK 1.1.x, some other three-letter time zone IDs
128  * (such as "PST", "CTT", "AST") are also supported. However, <strong>their
129  * use is deprecated</strong> because the same abbreviation is often used
130  * for multiple time zones (for example, "CST" could be U.S. "Central Standard
131  * Time" and "China Standard Time"), and the Java platform can then only
132  * recognize one of them.
133  *
134  *
135  * @see          Calendar
136  * @see          GregorianCalendar
137  * @see          SimpleTimeZone
138  * @author       Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
139  * @since        JDK1.1
140  */
141 abstract public class TimeZone implements Serializable, Cloneable {
142     /**
143      * Sole constructor.  (For invocation by subclass constructors, typically
144      * implicit.)
145      */
TimeZone()146     public TimeZone() {
147     }
148 
149     /**
150      * A style specifier for <code>getDisplayName()</code> indicating
151      * a short name, such as "PST."
152      * @see #LONG
153      * @since 1.2
154      */
155     public static final int SHORT = 0;
156 
157     /**
158      * A style specifier for <code>getDisplayName()</code> indicating
159      * a long name, such as "Pacific Standard Time."
160      * @see #SHORT
161      * @since 1.2
162      */
163     public static final int LONG  = 1;
164 
165     // Android-changed: Use a preload holder to allow compile-time initialization of TimeZone and
166     // dependents.
167     private static class NoImagePreloadHolder {
168         public static final Pattern CUSTOM_ZONE_ID_PATTERN = Pattern.compile("^GMT[-+](\\d{1,2})(:?(\\d\\d))?$");
169     }
170 
171     // Proclaim serialization compatibility with JDK 1.1
172     static final long serialVersionUID = 3581463369166924961L;
173 
174     // Android-changed: common timezone instances.
175     private static final TimeZone GMT = new SimpleTimeZone(0, "GMT");
176     private static final TimeZone UTC = new SimpleTimeZone(0, "UTC");
177 
178     /**
179      * Gets the time zone offset, for current date, modified in case of
180      * daylight savings. This is the offset to add to UTC to get local time.
181      * <p>
182      * This method returns a historically correct offset if an
183      * underlying <code>TimeZone</code> implementation subclass
184      * supports historical Daylight Saving Time schedule and GMT
185      * offset changes.
186      *
187      * @param era the era of the given date.
188      * @param year the year in the given date.
189      * @param month the month in the given date.
190      * Month is 0-based. e.g., 0 for January.
191      * @param day the day-in-month of the given date.
192      * @param dayOfWeek the day-of-week of the given date.
193      * @param milliseconds the milliseconds in day in <em>standard</em>
194      * local time.
195      *
196      * @return the offset in milliseconds to add to GMT to get local time.
197      *
198      * @see Calendar#ZONE_OFFSET
199      * @see Calendar#DST_OFFSET
200      */
getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds)201     public abstract int getOffset(int era, int year, int month, int day,
202                                   int dayOfWeek, int milliseconds);
203 
204     /**
205      * Returns the offset of this time zone from UTC at the specified
206      * date. If Daylight Saving Time is in effect at the specified
207      * date, the offset value is adjusted with the amount of daylight
208      * saving.
209      * <p>
210      * This method returns a historically correct offset value if an
211      * underlying TimeZone implementation subclass supports historical
212      * Daylight Saving Time schedule and GMT offset changes.
213      *
214      * @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT
215      * @return the amount of time in milliseconds to add to UTC to get local time.
216      *
217      * @see Calendar#ZONE_OFFSET
218      * @see Calendar#DST_OFFSET
219      * @since 1.4
220      */
getOffset(long date)221     public int getOffset(long date) {
222         if (inDaylightTime(new Date(date))) {
223             return getRawOffset() + getDSTSavings();
224         }
225         return getRawOffset();
226     }
227 
228     /**
229      * Gets the raw GMT offset and the amount of daylight saving of this
230      * time zone at the given time.
231      * @param date the milliseconds (since January 1, 1970,
232      * 00:00:00.000 GMT) at which the time zone offset and daylight
233      * saving amount are found
234      * @param offsets an array of int where the raw GMT offset
235      * (offset[0]) and daylight saving amount (offset[1]) are stored,
236      * or null if those values are not needed. The method assumes that
237      * the length of the given array is two or larger.
238      * @return the total amount of the raw GMT offset and daylight
239      * saving at the specified date.
240      *
241      * @see Calendar#ZONE_OFFSET
242      * @see Calendar#DST_OFFSET
243      */
getOffsets(long date, int[] offsets)244     int getOffsets(long date, int[] offsets) {
245         int rawoffset = getRawOffset();
246         int dstoffset = 0;
247         if (inDaylightTime(new Date(date))) {
248             dstoffset = getDSTSavings();
249         }
250         if (offsets != null) {
251             offsets[0] = rawoffset;
252             offsets[1] = dstoffset;
253         }
254         return rawoffset + dstoffset;
255     }
256 
257     /**
258      * Sets the base time zone offset to GMT.
259      * This is the offset to add to UTC to get local time.
260      * <p>
261      * If an underlying <code>TimeZone</code> implementation subclass
262      * supports historical GMT offset changes, the specified GMT
263      * offset is set as the latest GMT offset and the difference from
264      * the known latest GMT offset value is used to adjust all
265      * historical GMT offset values.
266      *
267      * @param offsetMillis the given base time zone offset to GMT.
268      */
setRawOffset(int offsetMillis)269     abstract public void setRawOffset(int offsetMillis);
270 
271     /**
272      * Returns the amount of time in milliseconds to add to UTC to get
273      * standard time in this time zone. Because this value is not
274      * affected by daylight saving time, it is called <I>raw
275      * offset</I>.
276      * <p>
277      * If an underlying <code>TimeZone</code> implementation subclass
278      * supports historical GMT offset changes, the method returns the
279      * raw offset value of the current date. In Honolulu, for example,
280      * its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and
281      * this method always returns -36000000 milliseconds (i.e., -10
282      * hours).
283      *
284      * @return the amount of raw offset time in milliseconds to add to UTC.
285      * @see Calendar#ZONE_OFFSET
286      */
getRawOffset()287     public abstract int getRawOffset();
288 
289     /**
290      * Gets the ID of this time zone.
291      * @return the ID of this time zone.
292      */
getID()293     public String getID()
294     {
295         return ID;
296     }
297 
298     /**
299      * Sets the time zone ID. This does not change any other data in
300      * the time zone object.
301      * @param ID the new time zone ID.
302      */
setID(String ID)303     public void setID(String ID)
304     {
305         if (ID == null) {
306             throw new NullPointerException();
307         }
308         this.ID = ID;
309     }
310 
311     /**
312      * Returns a long standard time name of this {@code TimeZone} suitable for
313      * presentation to the user in the default locale.
314      *
315      * <p>This method is equivalent to:
316      * <blockquote><pre>
317      * getDisplayName(false, {@link #LONG},
318      *                Locale.getDefault({@link Locale.Category#DISPLAY}))
319      * </pre></blockquote>
320      *
321      * @return the human-readable name of this time zone in the default locale.
322      * @since 1.2
323      * @see #getDisplayName(boolean, int, Locale)
324      * @see Locale#getDefault(Locale.Category)
325      * @see Locale.Category
326      */
getDisplayName()327     public final String getDisplayName() {
328         return getDisplayName(false, LONG,
329                               Locale.getDefault(Locale.Category.DISPLAY));
330     }
331 
332     /**
333      * Returns a long standard time name of this {@code TimeZone} suitable for
334      * presentation to the user in the specified {@code locale}.
335      *
336      * <p>This method is equivalent to:
337      * <blockquote><pre>
338      * getDisplayName(false, {@link #LONG}, locale)
339      * </pre></blockquote>
340      *
341      * @param locale the locale in which to supply the display name.
342      * @return the human-readable name of this time zone in the given locale.
343      * @exception NullPointerException if {@code locale} is {@code null}.
344      * @since 1.2
345      * @see #getDisplayName(boolean, int, Locale)
346      */
getDisplayName(Locale locale)347     public final String getDisplayName(Locale locale) {
348         return getDisplayName(false, LONG, locale);
349     }
350 
351     /**
352      * Returns a name in the specified {@code style} of this {@code TimeZone}
353      * suitable for presentation to the user in the default locale. If the
354      * specified {@code daylight} is {@code true}, a Daylight Saving Time name
355      * is returned (even if this {@code TimeZone} doesn't observe Daylight Saving
356      * Time). Otherwise, a Standard Time name is returned.
357      *
358      * <p>This method is equivalent to:
359      * <blockquote><pre>
360      * getDisplayName(daylight, style,
361      *                Locale.getDefault({@link Locale.Category#DISPLAY}))
362      * </pre></blockquote>
363      *
364      * @param daylight {@code true} specifying a Daylight Saving Time name, or
365      *                 {@code false} specifying a Standard Time name
366      * @param style either {@link #LONG} or {@link #SHORT}
367      * @return the human-readable name of this time zone in the default locale.
368      * @exception IllegalArgumentException if {@code style} is invalid.
369      * @since 1.2
370      * @see #getDisplayName(boolean, int, Locale)
371      * @see Locale#getDefault(Locale.Category)
372      * @see Locale.Category
373      * @see java.text.DateFormatSymbols#getZoneStrings()
374      */
getDisplayName(boolean daylight, int style)375     public final String getDisplayName(boolean daylight, int style) {
376         return getDisplayName(daylight, style,
377                               Locale.getDefault(Locale.Category.DISPLAY));
378     }
379 
380     /**
381      * Returns the {@link #SHORT short} or {@link #LONG long} name of this time
382      * zone with either standard or daylight time, as written in {@code locale}.
383      * If the name is not available, the result is in the format
384      * {@code GMT[+-]hh:mm}.
385      *
386      * @param daylightTime true for daylight time, false for standard time.
387      * @param style either {@link TimeZone#LONG} or {@link TimeZone#SHORT}.
388      * @param locale the display locale.
389      */
getDisplayName(boolean daylightTime, int style, Locale locale)390     public String getDisplayName(boolean daylightTime, int style, Locale locale) {
391         // BEGIN Android-changed: implement using android.icu.text.TimeZoneNames
392         TimeZoneNames.NameType nameType;
393         switch (style) {
394             case SHORT:
395                 nameType = daylightTime
396                         ? TimeZoneNames.NameType.SHORT_DAYLIGHT
397                         : TimeZoneNames.NameType.SHORT_STANDARD;
398                 break;
399             case LONG:
400                 nameType = daylightTime
401                         ? TimeZoneNames.NameType.LONG_DAYLIGHT
402                         : TimeZoneNames.NameType.LONG_STANDARD;
403                 break;
404             default:
405                 throw new IllegalArgumentException("Illegal style: " + style);
406         }
407         String canonicalID = android.icu.util.TimeZone.getCanonicalID(getID());
408         if (canonicalID != null) {
409             TimeZoneNames names = TimeZoneNames.getInstance(locale);
410             long now = System.currentTimeMillis();
411             String displayName = names.getDisplayName(canonicalID, nameType, now);
412             if (displayName != null) {
413                 return displayName;
414             }
415         }
416 
417         // We get here if this is a custom timezone or ICU doesn't have name data for the specific
418         // style and locale.
419         int offsetMillis = getRawOffset();
420         if (daylightTime) {
421             offsetMillis += getDSTSavings();
422         }
423         return createGmtOffsetString(true /* includeGmt */, true /* includeMinuteSeparator */,
424                 offsetMillis);
425         // END Android-changed: implement using android.icu.text.TimeZoneNames
426     }
427 
428     // BEGIN Android-added: utility method to format an offset as a GMT offset string.
429     /**
430      * Returns a string representation of an offset from UTC.
431      *
432      * <p>The format is "[GMT](+|-)HH[:]MM". The output is not localized.
433      *
434      * @param includeGmt true to include "GMT", false to exclude
435      * @param includeMinuteSeparator true to include the separator between hours and minutes, false
436      *     to exclude.
437      * @param offsetMillis the offset from UTC
438      *
439      * @hide used internally by SimpleDateFormat
440      */
createGmtOffsetString(boolean includeGmt, boolean includeMinuteSeparator, int offsetMillis)441     public static String createGmtOffsetString(boolean includeGmt,
442             boolean includeMinuteSeparator, int offsetMillis) {
443         int offsetMinutes = offsetMillis / 60000;
444         char sign = '+';
445         if (offsetMinutes < 0) {
446             sign = '-';
447             offsetMinutes = -offsetMinutes;
448         }
449         StringBuilder builder = new StringBuilder(9);
450         if (includeGmt) {
451             builder.append("GMT");
452         }
453         builder.append(sign);
454         appendNumber(builder, 2, offsetMinutes / 60);
455         if (includeMinuteSeparator) {
456             builder.append(':');
457         }
458         appendNumber(builder, 2, offsetMinutes % 60);
459         return builder.toString();
460     }
461 
appendNumber(StringBuilder builder, int count, int value)462     private static void appendNumber(StringBuilder builder, int count, int value) {
463         String string = Integer.toString(value);
464         for (int i = 0; i < count - string.length(); i++) {
465             builder.append('0');
466         }
467         builder.append(string);
468     }
469     // END Android-added: utility method to format an offset as a GMT offset string.
470 
471     /**
472      * Returns the amount of time to be added to local standard time
473      * to get local wall clock time.
474      *
475      * <p>The default implementation returns 3600000 milliseconds
476      * (i.e., one hour) if a call to {@link #useDaylightTime()}
477      * returns {@code true}. Otherwise, 0 (zero) is returned.
478      *
479      * <p>If an underlying {@code TimeZone} implementation subclass
480      * supports historical and future Daylight Saving Time schedule
481      * changes, this method returns the amount of saving time of the
482      * last known Daylight Saving Time rule that can be a future
483      * prediction.
484      *
485      * <p>If the amount of saving time at any given time stamp is
486      * required, construct a {@link Calendar} with this {@code
487      * TimeZone} and the time stamp, and call {@link Calendar#get(int)
488      * Calendar.get}{@code (}{@link Calendar#DST_OFFSET}{@code )}.
489      *
490      * @return the amount of saving time in milliseconds
491      * @since 1.4
492      * @see #inDaylightTime(Date)
493      * @see #getOffset(long)
494      * @see #getOffset(int,int,int,int,int,int)
495      * @see Calendar#ZONE_OFFSET
496      */
getDSTSavings()497     public int getDSTSavings() {
498         if (useDaylightTime()) {
499             return 3600000;
500         }
501         return 0;
502     }
503 
504     /**
505      * Queries if this {@code TimeZone} uses Daylight Saving Time.
506      *
507      * <p>If an underlying {@code TimeZone} implementation subclass
508      * supports historical and future Daylight Saving Time schedule
509      * changes, this method refers to the last known Daylight Saving Time
510      * rule that can be a future prediction and may not be the same as
511      * the current rule. Consider calling {@link #observesDaylightTime()}
512      * if the current rule should also be taken into account.
513      *
514      * @return {@code true} if this {@code TimeZone} uses Daylight Saving Time,
515      *         {@code false}, otherwise.
516      * @see #inDaylightTime(Date)
517      * @see Calendar#DST_OFFSET
518      */
useDaylightTime()519     public abstract boolean useDaylightTime();
520 
521     /**
522      * Returns {@code true} if this {@code TimeZone} is currently in
523      * Daylight Saving Time, or if a transition from Standard Time to
524      * Daylight Saving Time occurs at any future time.
525      *
526      * <p>The default implementation returns {@code true} if
527      * {@code useDaylightTime()} or {@code inDaylightTime(new Date())}
528      * returns {@code true}.
529      *
530      * @return {@code true} if this {@code TimeZone} is currently in
531      * Daylight Saving Time, or if a transition from Standard Time to
532      * Daylight Saving Time occurs at any future time; {@code false}
533      * otherwise.
534      * @since 1.7
535      * @see #useDaylightTime()
536      * @see #inDaylightTime(Date)
537      * @see Calendar#DST_OFFSET
538      */
observesDaylightTime()539     public boolean observesDaylightTime() {
540         return useDaylightTime() || inDaylightTime(new Date());
541     }
542 
543     /**
544      * Queries if the given {@code date} is in Daylight Saving Time in
545      * this time zone.
546      *
547      * @param date the given Date.
548      * @return {@code true} if the given date is in Daylight Saving Time,
549      *         {@code false}, otherwise.
550      */
inDaylightTime(Date date)551     abstract public boolean inDaylightTime(Date date);
552 
553     /**
554      * Gets the <code>TimeZone</code> for the given ID.
555      *
556      * @param id the ID for a <code>TimeZone</code>, either an abbreviation
557      * such as "PST", a full name such as "America/Los_Angeles", or a custom
558      * ID such as "GMT-8:00". Note that the support of abbreviations is
559      * for JDK 1.1.x compatibility only and full names should be used.
560      *
561      * @return the specified <code>TimeZone</code>, or the GMT zone if the given ID
562      * cannot be understood.
563      */
564     // Android-changed: param s/ID/id; use ZoneInfoDb instead of ZoneInfo class.
getTimeZone(String id)565     public static synchronized TimeZone getTimeZone(String id) {
566         if (id == null) {
567             throw new NullPointerException("id == null");
568         }
569 
570         // Special cases? These can clone an existing instance.
571         if (id.length() == 3) {
572             if (id.equals("GMT")) {
573                 return (TimeZone) GMT.clone();
574             }
575             if (id.equals("UTC")) {
576                 return (TimeZone) UTC.clone();
577             }
578         }
579 
580         // In the database?
581 
582         ZoneInfoData zoneInfoData = ZoneInfoDb.getInstance().makeZoneInfoData(id);
583         TimeZone zone = zoneInfoData == null ? null : ZoneInfo.createZoneInfo(zoneInfoData);
584 
585         // Custom time zone?
586         if (zone == null && id.length() > 3 && id.startsWith("GMT")) {
587             zone = getCustomTimeZone(id);
588         }
589 
590         // We never return null; on failure we return the equivalent of "GMT".
591         return (zone != null) ? zone : (TimeZone) GMT.clone();
592     }
593 
594     /**
595      * Gets the {@code TimeZone} for the given {@code zoneId}.
596      *
597      * @param zoneId a {@link ZoneId} from which the time zone ID is obtained
598      * @return the specified {@code TimeZone}, or the GMT zone if the given ID
599      *         cannot be understood.
600      * @throws NullPointerException if {@code zoneId} is {@code null}
601      * @since 1.8
602      */
getTimeZone(ZoneId zoneId)603     public static TimeZone getTimeZone(ZoneId zoneId) {
604         String tzid = zoneId.getId(); // throws an NPE if null
605         char c = tzid.charAt(0);
606         if (c == '+' || c == '-') {
607             tzid = "GMT" + tzid;
608         } else if (c == 'Z' && tzid.length() == 1) {
609             tzid = "UTC";
610         }
611         return getTimeZone(tzid);
612     }
613 
614     /**
615      * Converts this {@code TimeZone} object to a {@code ZoneId}.
616      *
617      * @return a {@code ZoneId} representing the same time zone as this
618      *         {@code TimeZone}
619      * @since 1.8
620      */
toZoneId()621     public ZoneId toZoneId() {
622         // Android-changed: don't support "old mapping"
623         return ZoneId.of(getID(), ZoneId.SHORT_IDS);
624     }
625 
626     /**
627      * Returns a new SimpleTimeZone for an ID of the form "GMT[+|-]hh[[:]mm]", or null.
628      */
getCustomTimeZone(String id)629     private static TimeZone getCustomTimeZone(String id) {
630         Matcher m = NoImagePreloadHolder.CUSTOM_ZONE_ID_PATTERN.matcher(id);
631         if (!m.matches()) {
632             return null;
633         }
634 
635         int hour;
636         int minute = 0;
637         try {
638             hour = Integer.parseInt(m.group(1));
639             if (m.group(3) != null) {
640                 minute = Integer.parseInt(m.group(3));
641             }
642         } catch (NumberFormatException impossible) {
643             throw new AssertionError(impossible);
644         }
645 
646         if (hour < 0 || hour > 23 || minute < 0 || minute > 59) {
647             return null;
648         }
649 
650         char sign = id.charAt(3);
651         int raw = (hour * 3600000) + (minute * 60000);
652         if (sign == '-') {
653             raw = -raw;
654         }
655 
656         String cleanId = String.format(Locale.ROOT, "GMT%c%02d:%02d", sign, hour, minute);
657 
658         return new SimpleTimeZone(raw, cleanId);
659     }
660 
661     /**
662      * Gets the available IDs according to the given time zone offset in milliseconds.
663      *
664      * @param rawOffset the given time zone GMT offset in milliseconds.
665      * @return an array of IDs, where the time zone for that ID has
666      * the specified GMT offset. For example, "America/Phoenix" and "America/Denver"
667      * both have GMT-07:00, but differ in daylight saving behavior.
668      * @see #getRawOffset()
669      */
getAvailableIDs(int rawOffset)670     public static synchronized String[] getAvailableIDs(int rawOffset) {
671         return ZoneInfoDb.getInstance().getAvailableIDs(rawOffset);
672     }
673 
674     /**
675      * Gets all the available IDs supported.
676      * @return an array of IDs.
677      */
getAvailableIDs()678     public static synchronized String[] getAvailableIDs() {
679         return ZoneInfoDb.getInstance().getAvailableIDs();
680     }
681 
682     /**
683      * Gets the platform defined TimeZone ID.
684      **/
getSystemTimeZoneID(String javaHome, String country)685     private static native String getSystemTimeZoneID(String javaHome,
686                                                      String country);
687 
688     /**
689      * Gets the custom time zone ID based on the GMT offset of the
690      * platform. (e.g., "GMT+08:00")
691      */
getSystemGMTOffsetID()692     private static native String getSystemGMTOffsetID();
693 
694     /**
695      * Gets the default <code>TimeZone</code> for this host.
696      * The source of the default <code>TimeZone</code>
697      * may vary with implementation.
698      * @return a default <code>TimeZone</code>.
699      * @see #setDefault
700      */
getDefault()701     public static TimeZone getDefault() {
702         return (TimeZone) getDefaultRef().clone();
703     }
704 
705     /**
706      * Returns the reference to the default TimeZone object. This
707      * method doesn't create a clone.
708      */
getDefaultRef()709     static synchronized TimeZone getDefaultRef() {
710         if (defaultTimeZone == null) {
711             Supplier<String> tzGetter = RuntimeHooks.getTimeZoneIdSupplier();
712             String zoneName = (tzGetter != null) ? tzGetter.get() : null;
713             if (zoneName != null) {
714                 zoneName = zoneName.trim();
715             }
716             if (zoneName == null || zoneName.isEmpty()) {
717                 try {
718                     // On the host, we can find the configured timezone here.
719                     zoneName = IoUtils.readFileAsString("/etc/timezone");
720                 } catch (IOException ex) {
721                     // "vogar --mode device" can end up here.
722                     // TODO: give libcore access to Android system properties and read "persist.sys.timezone".
723                     zoneName = "GMT";
724                 }
725             }
726             defaultTimeZone = TimeZone.getTimeZone(zoneName);
727         }
728         return defaultTimeZone;
729     }
730 
731     /**
732      * Sets the {@code TimeZone} that is returned by the {@code getDefault}
733      * method. {@code timeZone} is cached. If {@code timeZone} is null, the cached
734      * default {@code TimeZone} is cleared. This method doesn't change the value
735      * of the {@code user.timezone} property.
736      *
737      * @param timeZone the new default {@code TimeZone}, or null
738      * @see #getDefault
739      */
740     // Android-changed: s/zone/timeZone, synchronized, removed mention of SecurityException
setDefault(TimeZone timeZone)741     public synchronized static void setDefault(TimeZone timeZone)
742     {
743         SecurityManager sm = System.getSecurityManager();
744         if (sm != null) {
745             sm.checkPermission(new PropertyPermission
746                     ("user.timezone", "write"));
747         }
748         defaultTimeZone = timeZone != null ? (TimeZone) timeZone.clone() : null;
749         // Android-changed: notify ICU4J of changed default TimeZone.
750         ExtendedTimeZone.clearDefaultTimeZone();
751     }
752 
753     /**
754      * Returns true if this zone has the same rule and offset as another zone.
755      * That is, if this zone differs only in ID, if at all.  Returns false
756      * if the other zone is null.
757      * @param other the <code>TimeZone</code> object to be compared with
758      * @return true if the other zone is not null and is the same as this one,
759      * with the possible exception of the ID
760      * @since 1.2
761      */
hasSameRules(TimeZone other)762     public boolean hasSameRules(TimeZone other) {
763         return other != null && getRawOffset() == other.getRawOffset() &&
764             useDaylightTime() == other.useDaylightTime();
765     }
766 
767     /**
768      * Creates a copy of this <code>TimeZone</code>.
769      *
770      * @return a clone of this <code>TimeZone</code>
771      */
clone()772     public Object clone()
773     {
774         try {
775             TimeZone other = (TimeZone) super.clone();
776             other.ID = ID;
777             return other;
778         } catch (CloneNotSupportedException e) {
779             throw new InternalError(e);
780         }
781     }
782 
783     /**
784      * The null constant as a TimeZone.
785      */
786     static final TimeZone NO_TIMEZONE = null;
787 
788     // =======================privates===============================
789 
790     /**
791      * The string identifier of this <code>TimeZone</code>.  This is a
792      * programmatic identifier used internally to look up <code>TimeZone</code>
793      * objects from the system table and also to map them to their localized
794      * display names.  <code>ID</code> values are unique in the system
795      * table but may not be for dynamically created zones.
796      * @serial
797      */
798     private String           ID;
799     private static volatile TimeZone defaultTimeZone;
800 }
801