| /* |
| * Copyright (c) 1996, 2015, 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. |
| */ |
| |
| /* |
| * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved |
| * (C) Copyright IBM Corp. 1996 - All Rights Reserved |
| * |
| * The original version of this source code and documentation is copyrighted |
| * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These |
| * materials are provided under terms of a License Agreement between Taligent |
| * and Sun. This technology is protected by multiple US and International |
| * patents. This notice and attribution to Taligent may not be removed. |
| * Taligent is a registered trademark of Taligent, Inc. |
| * |
| */ |
| |
| package java.util; |
| |
| import java.io.Serializable; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.time.ZoneId; |
| import java.util.Properties; |
| import sun.security.action.GetPropertyAction; |
| import sun.util.calendar.ZoneInfo; |
| import sun.util.calendar.ZoneInfoFile; |
| import sun.util.locale.provider.TimeZoneNameUtility; |
| |
| /** |
| * <code>TimeZone</code> represents a time zone offset, and also figures out daylight |
| * savings. |
| * |
| * <p> |
| * Typically, you get a <code>TimeZone</code> using <code>getDefault</code> |
| * which creates a <code>TimeZone</code> based on the time zone where the program |
| * is running. For example, for a program running in Japan, <code>getDefault</code> |
| * creates a <code>TimeZone</code> object based on Japanese Standard Time. |
| * |
| * <p> |
| * You can also get a <code>TimeZone</code> using <code>getTimeZone</code> |
| * along with a time zone ID. For instance, the time zone ID for the |
| * U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a |
| * U.S. Pacific Time <code>TimeZone</code> object with: |
| * <blockquote><pre> |
| * TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles"); |
| * </pre></blockquote> |
| * You can use the <code>getAvailableIDs</code> method to iterate through |
| * all the supported time zone IDs. You can then choose a |
| * supported ID to get a <code>TimeZone</code>. |
| * If the time zone you want is not represented by one of the |
| * supported IDs, then a custom time zone ID can be specified to |
| * produce a TimeZone. The syntax of a custom time zone ID is: |
| * |
| * <blockquote><pre> |
| * <a id="CustomID"><i>CustomID:</i></a> |
| * <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i> |
| * <code>GMT</code> <i>Sign</i> <i>Hours</i> <i>Minutes</i> |
| * <code>GMT</code> <i>Sign</i> <i>Hours</i> |
| * <i>Sign:</i> one of |
| * <code>+ -</code> |
| * <i>Hours:</i> |
| * <i>Digit</i> |
| * <i>Digit</i> <i>Digit</i> |
| * <i>Minutes:</i> |
| * <i>Digit</i> <i>Digit</i> |
| * <i>Digit:</i> one of |
| * <code>0 1 2 3 4 5 6 7 8 9</code> |
| * </pre></blockquote> |
| * |
| * <i>Hours</i> must be between 0 to 23 and <i>Minutes</i> must be |
| * between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten |
| * hours and ten minutes ahead of GMT, respectively. |
| * <p> |
| * The format is locale independent and digits must be taken from the |
| * Basic Latin block of the Unicode standard. No daylight saving time |
| * transition schedule can be specified with a custom time zone ID. If |
| * the specified string doesn't match the syntax, <code>"GMT"</code> |
| * is used. |
| * <p> |
| * When creating a <code>TimeZone</code>, the specified custom time |
| * zone ID is normalized in the following syntax: |
| * <blockquote><pre> |
| * <a id="NormalizedCustomID"><i>NormalizedCustomID:</i></a> |
| * <code>GMT</code> <i>Sign</i> <i>TwoDigitHours</i> <code>:</code> <i>Minutes</i> |
| * <i>Sign:</i> one of |
| * <code>+ -</code> |
| * <i>TwoDigitHours:</i> |
| * <i>Digit</i> <i>Digit</i> |
| * <i>Minutes:</i> |
| * <i>Digit</i> <i>Digit</i> |
| * <i>Digit:</i> one of |
| * <code>0 1 2 3 4 5 6 7 8 9</code> |
| * </pre></blockquote> |
| * For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00". |
| * |
| * <h3>Three-letter time zone IDs</h3> |
| * |
| * For compatibility with JDK 1.1.x, some other three-letter time zone IDs |
| * (such as "PST", "CTT", "AST") are also supported. However, <strong>their |
| * use is deprecated</strong> because the same abbreviation is often used |
| * for multiple time zones (for example, "CST" could be U.S. "Central Standard |
| * Time" and "China Standard Time"), and the Java platform can then only |
| * recognize one of them. |
| * |
| * |
| * @see Calendar |
| * @see GregorianCalendar |
| * @see SimpleTimeZone |
| * @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu |
| * @since 1.1 |
| */ |
| public abstract class TimeZone implements Serializable, Cloneable { |
| /** |
| * Sole constructor. (For invocation by subclass constructors, typically |
| * implicit.) |
| */ |
| public TimeZone() { |
| } |
| |
| /** |
| * A style specifier for <code>getDisplayName()</code> indicating |
| * a short name, such as "PST." |
| * @see #LONG |
| * @since 1.2 |
| */ |
| public static final int SHORT = 0; |
| |
| /** |
| * A style specifier for <code>getDisplayName()</code> indicating |
| * a long name, such as "Pacific Standard Time." |
| * @see #SHORT |
| * @since 1.2 |
| */ |
| public static final int LONG = 1; |
| |
| // Constants used internally; unit is milliseconds |
| private static final int ONE_MINUTE = 60*1000; |
| private static final int ONE_HOUR = 60*ONE_MINUTE; |
| private static final int ONE_DAY = 24*ONE_HOUR; |
| |
| // Proclaim serialization compatibility with JDK 1.1 |
| static final long serialVersionUID = 3581463369166924961L; |
| |
| /** |
| * Gets the time zone offset, for current date, modified in case of |
| * daylight savings. This is the offset to add to UTC to get local time. |
| * <p> |
| * This method returns a historically correct offset if an |
| * underlying <code>TimeZone</code> implementation subclass |
| * supports historical Daylight Saving Time schedule and GMT |
| * offset changes. |
| * |
| * @param era the era of the given date. |
| * @param year the year in the given date. |
| * @param month the month in the given date. |
| * Month is 0-based. e.g., 0 for January. |
| * @param day the day-in-month of the given date. |
| * @param dayOfWeek the day-of-week of the given date. |
| * @param milliseconds the milliseconds in day in <em>standard</em> |
| * local time. |
| * |
| * @return the offset in milliseconds to add to GMT to get local time. |
| * |
| * @see Calendar#ZONE_OFFSET |
| * @see Calendar#DST_OFFSET |
| */ |
| public abstract int getOffset(int era, int year, int month, int day, |
| int dayOfWeek, int milliseconds); |
| |
| /** |
| * Returns the offset of this time zone from UTC at the specified |
| * date. If Daylight Saving Time is in effect at the specified |
| * date, the offset value is adjusted with the amount of daylight |
| * saving. |
| * <p> |
| * This method returns a historically correct offset value if an |
| * underlying TimeZone implementation subclass supports historical |
| * Daylight Saving Time schedule and GMT offset changes. |
| * |
| * @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT |
| * @return the amount of time in milliseconds to add to UTC to get local time. |
| * |
| * @see Calendar#ZONE_OFFSET |
| * @see Calendar#DST_OFFSET |
| * @since 1.4 |
| */ |
| public int getOffset(long date) { |
| if (inDaylightTime(new Date(date))) { |
| return getRawOffset() + getDSTSavings(); |
| } |
| return getRawOffset(); |
| } |
| |
| /** |
| * Gets the raw GMT offset and the amount of daylight saving of this |
| * time zone at the given time. |
| * @param date the milliseconds (since January 1, 1970, |
| * 00:00:00.000 GMT) at which the time zone offset and daylight |
| * saving amount are found |
| * @param offsets an array of int where the raw GMT offset |
| * (offset[0]) and daylight saving amount (offset[1]) are stored, |
| * or null if those values are not needed. The method assumes that |
| * the length of the given array is two or larger. |
| * @return the total amount of the raw GMT offset and daylight |
| * saving at the specified date. |
| * |
| * @see Calendar#ZONE_OFFSET |
| * @see Calendar#DST_OFFSET |
| */ |
| int getOffsets(long date, int[] offsets) { |
| int rawoffset = getRawOffset(); |
| int dstoffset = 0; |
| if (inDaylightTime(new Date(date))) { |
| dstoffset = getDSTSavings(); |
| } |
| if (offsets != null) { |
| offsets[0] = rawoffset; |
| offsets[1] = dstoffset; |
| } |
| return rawoffset + dstoffset; |
| } |
| |
| /** |
| * Sets the base time zone offset to GMT. |
| * This is the offset to add to UTC to get local time. |
| * <p> |
| * If an underlying <code>TimeZone</code> implementation subclass |
| * supports historical GMT offset changes, the specified GMT |
| * offset is set as the latest GMT offset and the difference from |
| * the known latest GMT offset value is used to adjust all |
| * historical GMT offset values. |
| * |
| * @param offsetMillis the given base time zone offset to GMT. |
| */ |
| public abstract void setRawOffset(int offsetMillis); |
| |
| /** |
| * Returns the amount of time in milliseconds to add to UTC to get |
| * standard time in this time zone. Because this value is not |
| * affected by daylight saving time, it is called <I>raw |
| * offset</I>. |
| * <p> |
| * If an underlying <code>TimeZone</code> implementation subclass |
| * supports historical GMT offset changes, the method returns the |
| * raw offset value of the current date. In Honolulu, for example, |
| * its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and |
| * this method always returns -36000000 milliseconds (i.e., -10 |
| * hours). |
| * |
| * @return the amount of raw offset time in milliseconds to add to UTC. |
| * @see Calendar#ZONE_OFFSET |
| */ |
| public abstract int getRawOffset(); |
| |
| /** |
| * Gets the ID of this time zone. |
| * @return the ID of this time zone. |
| */ |
| public String getID() |
| { |
| return ID; |
| } |
| |
| /** |
| * Sets the time zone ID. This does not change any other data in |
| * the time zone object. |
| * @param ID the new time zone ID. |
| */ |
| public void setID(String ID) |
| { |
| if (ID == null) { |
| throw new NullPointerException(); |
| } |
| this.ID = ID; |
| this.zoneId = null; // invalidate cache |
| } |
| |
| /** |
| * Returns a long standard time name of this {@code TimeZone} suitable for |
| * presentation to the user in the default locale. |
| * |
| * <p>This method is equivalent to: |
| * <blockquote><pre> |
| * getDisplayName(false, {@link #LONG}, |
| * Locale.getDefault({@link Locale.Category#DISPLAY})) |
| * </pre></blockquote> |
| * |
| * @return the human-readable name of this time zone in the default locale. |
| * @since 1.2 |
| * @see #getDisplayName(boolean, int, Locale) |
| * @see Locale#getDefault(Locale.Category) |
| * @see Locale.Category |
| */ |
| public final String getDisplayName() { |
| return getDisplayName(false, LONG, |
| Locale.getDefault(Locale.Category.DISPLAY)); |
| } |
| |
| /** |
| * Returns a long standard time name of this {@code TimeZone} suitable for |
| * presentation to the user in the specified {@code locale}. |
| * |
| * <p>This method is equivalent to: |
| * <blockquote><pre> |
| * getDisplayName(false, {@link #LONG}, locale) |
| * </pre></blockquote> |
| * |
| * @param locale the locale in which to supply the display name. |
| * @return the human-readable name of this time zone in the given locale. |
| * @exception NullPointerException if {@code locale} is {@code null}. |
| * @since 1.2 |
| * @see #getDisplayName(boolean, int, Locale) |
| */ |
| public final String getDisplayName(Locale locale) { |
| return getDisplayName(false, LONG, locale); |
| } |
| |
| /** |
| * Returns a name in the specified {@code style} of this {@code TimeZone} |
| * suitable for presentation to the user in the default locale. If the |
| * specified {@code daylight} is {@code true}, a Daylight Saving Time name |
| * is returned (even if this {@code TimeZone} doesn't observe Daylight Saving |
| * Time). Otherwise, a Standard Time name is returned. |
| * |
| * <p>This method is equivalent to: |
| * <blockquote><pre> |
| * getDisplayName(daylight, style, |
| * Locale.getDefault({@link Locale.Category#DISPLAY})) |
| * </pre></blockquote> |
| * |
| * @param daylight {@code true} specifying a Daylight Saving Time name, or |
| * {@code false} specifying a Standard Time name |
| * @param style either {@link #LONG} or {@link #SHORT} |
| * @return the human-readable name of this time zone in the default locale. |
| * @exception IllegalArgumentException if {@code style} is invalid. |
| * @since 1.2 |
| * @see #getDisplayName(boolean, int, Locale) |
| * @see Locale#getDefault(Locale.Category) |
| * @see Locale.Category |
| * @see java.text.DateFormatSymbols#getZoneStrings() |
| */ |
| public final String getDisplayName(boolean daylight, int style) { |
| return getDisplayName(daylight, style, |
| Locale.getDefault(Locale.Category.DISPLAY)); |
| } |
| |
| /** |
| * Returns a name in the specified {@code style} of this {@code TimeZone} |
| * suitable for presentation to the user in the specified {@code |
| * locale}. If the specified {@code daylight} is {@code true}, a Daylight |
| * Saving Time name is returned (even if this {@code TimeZone} doesn't |
| * observe Daylight Saving Time). Otherwise, a Standard Time name is |
| * returned. |
| * |
| * <p>When looking up a time zone name, the {@linkplain |
| * ResourceBundle.Control#getCandidateLocales(String,Locale) default |
| * <code>Locale</code> search path of <code>ResourceBundle</code>} derived |
| * from the specified {@code locale} is used. (No {@linkplain |
| * ResourceBundle.Control#getFallbackLocale(String,Locale) fallback |
| * <code>Locale</code>} search is performed.) If a time zone name in any |
| * {@code Locale} of the search path, including {@link Locale#ROOT}, is |
| * found, the name is returned. Otherwise, a string in the |
| * <a href="#NormalizedCustomID">normalized custom ID format</a> is returned. |
| * |
| * @param daylight {@code true} specifying a Daylight Saving Time name, or |
| * {@code false} specifying a Standard Time name |
| * @param style either {@link #LONG} or {@link #SHORT} |
| * @param locale the locale in which to supply the display name. |
| * @return the human-readable name of this time zone in the given locale. |
| * @exception IllegalArgumentException if {@code style} is invalid. |
| * @exception NullPointerException if {@code locale} is {@code null}. |
| * @since 1.2 |
| * @see java.text.DateFormatSymbols#getZoneStrings() |
| */ |
| public String getDisplayName(boolean daylight, int style, Locale locale) { |
| if (style != SHORT && style != LONG) { |
| throw new IllegalArgumentException("Illegal style: " + style); |
| } |
| String id = getID(); |
| String name = TimeZoneNameUtility.retrieveDisplayName(id, daylight, style, locale); |
| if (name != null) { |
| return name; |
| } |
| |
| if (id.startsWith("GMT") && id.length() > 3) { |
| char sign = id.charAt(3); |
| if (sign == '+' || sign == '-') { |
| return id; |
| } |
| } |
| int offset = getRawOffset(); |
| if (daylight) { |
| offset += getDSTSavings(); |
| } |
| return ZoneInfoFile.toCustomID(offset); |
| } |
| |
| private static String[] getDisplayNames(String id, Locale locale) { |
| return TimeZoneNameUtility.retrieveDisplayNames(id, locale); |
| } |
| |
| /** |
| * Returns the amount of time to be added to local standard time |
| * to get local wall clock time. |
| * |
| * <p>The default implementation returns 3600000 milliseconds |
| * (i.e., one hour) if a call to {@link #useDaylightTime()} |
| * returns {@code true}. Otherwise, 0 (zero) is returned. |
| * |
| * <p>If an underlying {@code TimeZone} implementation subclass |
| * supports historical and future Daylight Saving Time schedule |
| * changes, this method returns the amount of saving time of the |
| * last known Daylight Saving Time rule that can be a future |
| * prediction. |
| * |
| * <p>If the amount of saving time at any given time stamp is |
| * required, construct a {@link Calendar} with this {@code |
| * TimeZone} and the time stamp, and call {@link Calendar#get(int) |
| * Calendar.get}{@code (}{@link Calendar#DST_OFFSET}{@code )}. |
| * |
| * @return the amount of saving time in milliseconds |
| * @since 1.4 |
| * @see #inDaylightTime(Date) |
| * @see #getOffset(long) |
| * @see #getOffset(int,int,int,int,int,int) |
| * @see Calendar#ZONE_OFFSET |
| */ |
| public int getDSTSavings() { |
| if (useDaylightTime()) { |
| return 3600000; |
| } |
| return 0; |
| } |
| |
| /** |
| * Queries if this {@code TimeZone} uses Daylight Saving Time. |
| * |
| * <p>If an underlying {@code TimeZone} implementation subclass |
| * supports historical and future Daylight Saving Time schedule |
| * changes, this method refers to the last known Daylight Saving Time |
| * rule that can be a future prediction and may not be the same as |
| * the current rule. Consider calling {@link #observesDaylightTime()} |
| * if the current rule should also be taken into account. |
| * |
| * @return {@code true} if this {@code TimeZone} uses Daylight Saving Time, |
| * {@code false}, otherwise. |
| * @see #inDaylightTime(Date) |
| * @see Calendar#DST_OFFSET |
| */ |
| public abstract boolean useDaylightTime(); |
| |
| /** |
| * Returns {@code true} if this {@code TimeZone} is currently in |
| * Daylight Saving Time, or if a transition from Standard Time to |
| * Daylight Saving Time occurs at any future time. |
| * |
| * <p>The default implementation returns {@code true} if |
| * {@code useDaylightTime()} or {@code inDaylightTime(new Date())} |
| * returns {@code true}. |
| * |
| * @return {@code true} if this {@code TimeZone} is currently in |
| * Daylight Saving Time, or if a transition from Standard Time to |
| * Daylight Saving Time occurs at any future time; {@code false} |
| * otherwise. |
| * @since 1.7 |
| * @see #useDaylightTime() |
| * @see #inDaylightTime(Date) |
| * @see Calendar#DST_OFFSET |
| */ |
| public boolean observesDaylightTime() { |
| return useDaylightTime() || inDaylightTime(new Date()); |
| } |
| |
| /** |
| * Queries if the given {@code date} is in Daylight Saving Time in |
| * this time zone. |
| * |
| * @param date the given Date. |
| * @return {@code true} if the given date is in Daylight Saving Time, |
| * {@code false}, otherwise. |
| */ |
| public abstract boolean inDaylightTime(Date date); |
| |
| /** |
| * Gets the <code>TimeZone</code> for the given ID. |
| * |
| * @param ID the ID for a <code>TimeZone</code>, either an abbreviation |
| * such as "PST", a full name such as "America/Los_Angeles", or a custom |
| * ID such as "GMT-8:00". Note that the support of abbreviations is |
| * for JDK 1.1.x compatibility only and full names should be used. |
| * |
| * @return the specified <code>TimeZone</code>, or the GMT zone if the given ID |
| * cannot be understood. |
| */ |
| public static synchronized TimeZone getTimeZone(String ID) { |
| return getTimeZone(ID, true); |
| } |
| |
| /** |
| * Gets the {@code TimeZone} for the given {@code zoneId}. |
| * |
| * @param zoneId a {@link ZoneId} from which the time zone ID is obtained |
| * @return the specified {@code TimeZone}, or the GMT zone if the given ID |
| * cannot be understood. |
| * @throws NullPointerException if {@code zoneId} is {@code null} |
| * @since 1.8 |
| */ |
| public static TimeZone getTimeZone(ZoneId zoneId) { |
| String tzid = zoneId.getId(); // throws an NPE if null |
| char c = tzid.charAt(0); |
| if (c == '+' || c == '-') { |
| tzid = "GMT" + tzid; |
| } else if (c == 'Z' && tzid.length() == 1) { |
| tzid = "UTC"; |
| } |
| return getTimeZone(tzid, true); |
| } |
| |
| /** |
| * Converts this {@code TimeZone} object to a {@code ZoneId}. |
| * |
| * @return a {@code ZoneId} representing the same time zone as this |
| * {@code TimeZone} |
| * @since 1.8 |
| */ |
| public ZoneId toZoneId() { |
| ZoneId zId = zoneId; |
| if (zId == null) { |
| zoneId = zId = toZoneId0(); |
| } |
| return zId; |
| } |
| |
| private ZoneId toZoneId0() { |
| String id = getID(); |
| TimeZone defaultZone = defaultTimeZone; |
| // are we not defaultTimeZone but our id is equal to default's? |
| if (defaultZone != this && |
| defaultZone != null && id.equals(defaultZone.getID())) { |
| // delegate to default TZ which is effectively immutable |
| return defaultZone.toZoneId(); |
| } |
| // derive it ourselves |
| if (ZoneInfoFile.useOldMapping() && id.length() == 3) { |
| if ("EST".equals(id)) |
| return ZoneId.of("America/New_York"); |
| if ("MST".equals(id)) |
| return ZoneId.of("America/Denver"); |
| if ("HST".equals(id)) |
| return ZoneId.of("America/Honolulu"); |
| } |
| return ZoneId.of(id, ZoneId.SHORT_IDS); |
| } |
| |
| private static TimeZone getTimeZone(String ID, boolean fallback) { |
| TimeZone tz = ZoneInfo.getTimeZone(ID); |
| if (tz == null) { |
| tz = parseCustomTimeZone(ID); |
| if (tz == null && fallback) { |
| tz = new ZoneInfo(GMT_ID, 0); |
| } |
| } |
| return tz; |
| } |
| |
| /** |
| * Gets the available IDs according to the given time zone offset in milliseconds. |
| * |
| * @param rawOffset the given time zone GMT offset in milliseconds. |
| * @return an array of IDs, where the time zone for that ID has |
| * the specified GMT offset. For example, "America/Phoenix" and "America/Denver" |
| * both have GMT-07:00, but differ in daylight saving behavior. |
| * @see #getRawOffset() |
| */ |
| public static synchronized String[] getAvailableIDs(int rawOffset) { |
| return ZoneInfo.getAvailableIDs(rawOffset); |
| } |
| |
| /** |
| * Gets all the available IDs supported. |
| * @return an array of IDs. |
| */ |
| public static synchronized String[] getAvailableIDs() { |
| return ZoneInfo.getAvailableIDs(); |
| } |
| |
| /** |
| * Gets the platform defined TimeZone ID. |
| **/ |
| private static native String getSystemTimeZoneID(String javaHome); |
| |
| /** |
| * Gets the custom time zone ID based on the GMT offset of the |
| * platform. (e.g., "GMT+08:00") |
| */ |
| private static native String getSystemGMTOffsetID(); |
| |
| /** |
| * Gets the default {@code TimeZone} of the Java virtual machine. If the |
| * cached default {@code TimeZone} is available, its clone is returned. |
| * Otherwise, the method takes the following steps to determine the default |
| * time zone. |
| * |
| * <ul> |
| * <li>Use the {@code user.timezone} property value as the default |
| * time zone ID if it's available.</li> |
| * <li>Detect the platform time zone ID. The source of the |
| * platform time zone and ID mapping may vary with implementation.</li> |
| * <li>Use {@code GMT} as the last resort if the given or detected |
| * time zone ID is unknown.</li> |
| * </ul> |
| * |
| * <p>The default {@code TimeZone} created from the ID is cached, |
| * and its clone is returned. The {@code user.timezone} property |
| * value is set to the ID upon return. |
| * |
| * @return the default {@code TimeZone} |
| * @see #setDefault(TimeZone) |
| */ |
| public static TimeZone getDefault() { |
| return (TimeZone) getDefaultRef().clone(); |
| } |
| |
| /** |
| * Returns the reference to the default TimeZone object. This |
| * method doesn't create a clone. |
| */ |
| static TimeZone getDefaultRef() { |
| TimeZone defaultZone = defaultTimeZone; |
| if (defaultZone == null) { |
| // Need to initialize the default time zone. |
| defaultZone = setDefaultZone(); |
| assert defaultZone != null; |
| } |
| // Don't clone here. |
| return defaultZone; |
| } |
| |
| private static synchronized TimeZone setDefaultZone() { |
| TimeZone tz; |
| // get the time zone ID from the system properties |
| Properties props = GetPropertyAction.privilegedGetProperties(); |
| String zoneID = props.getProperty("user.timezone"); |
| |
| // if the time zone ID is not set (yet), perform the |
| // platform to Java time zone ID mapping. |
| if (zoneID == null || zoneID.isEmpty()) { |
| String javaHome = props.getProperty("java.home"); |
| try { |
| zoneID = getSystemTimeZoneID(javaHome); |
| if (zoneID == null) { |
| zoneID = GMT_ID; |
| } |
| } catch (NullPointerException e) { |
| zoneID = GMT_ID; |
| } |
| } |
| |
| // Get the time zone for zoneID. But not fall back to |
| // "GMT" here. |
| tz = getTimeZone(zoneID, false); |
| |
| if (tz == null) { |
| // If the given zone ID is unknown in Java, try to |
| // get the GMT-offset-based time zone ID, |
| // a.k.a. custom time zone ID (e.g., "GMT-08:00"). |
| String gmtOffsetID = getSystemGMTOffsetID(); |
| if (gmtOffsetID != null) { |
| zoneID = gmtOffsetID; |
| } |
| tz = getTimeZone(zoneID, true); |
| } |
| assert tz != null; |
| |
| final String id = zoneID; |
| props.setProperty("user.timezone", id); |
| |
| defaultTimeZone = tz; |
| return tz; |
| } |
| |
| /** |
| * Sets the {@code TimeZone} that is returned by the {@code getDefault} |
| * method. {@code zone} is cached. If {@code zone} is null, the cached |
| * default {@code TimeZone} is cleared. This method doesn't change the value |
| * of the {@code user.timezone} property. |
| * |
| * @param zone the new default {@code TimeZone}, or null |
| * @throws SecurityException if the security manager's {@code checkPermission} |
| * denies {@code PropertyPermission("user.timezone", |
| * "write")} |
| * @see #getDefault |
| * @see PropertyPermission |
| */ |
| public static void setDefault(TimeZone zone) |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| sm.checkPermission(new PropertyPermission |
| ("user.timezone", "write")); |
| } |
| // by saving a defensive clone and returning a clone in getDefault() too, |
| // the defaultTimeZone instance is isolated from user code which makes it |
| // effectively immutable. This is important to avoid races when the |
| // following is evaluated in ZoneId.systemDefault(): |
| // TimeZone.getDefault().toZoneId(). |
| defaultTimeZone = (zone == null) ? null : (TimeZone) zone.clone(); |
| } |
| |
| /** |
| * Returns true if this zone has the same rule and offset as another zone. |
| * That is, if this zone differs only in ID, if at all. Returns false |
| * if the other zone is null. |
| * @param other the <code>TimeZone</code> object to be compared with |
| * @return true if the other zone is not null and is the same as this one, |
| * with the possible exception of the ID |
| * @since 1.2 |
| */ |
| public boolean hasSameRules(TimeZone other) { |
| return other != null && getRawOffset() == other.getRawOffset() && |
| useDaylightTime() == other.useDaylightTime(); |
| } |
| |
| /** |
| * Creates a copy of this <code>TimeZone</code>. |
| * |
| * @return a clone of this <code>TimeZone</code> |
| */ |
| public Object clone() |
| { |
| try { |
| return super.clone(); |
| } catch (CloneNotSupportedException e) { |
| throw new InternalError(e); |
| } |
| } |
| |
| /** |
| * The null constant as a TimeZone. |
| */ |
| static final TimeZone NO_TIMEZONE = null; |
| |
| // =======================privates=============================== |
| |
| /** |
| * The string identifier of this <code>TimeZone</code>. This is a |
| * programmatic identifier used internally to look up <code>TimeZone</code> |
| * objects from the system table and also to map them to their localized |
| * display names. <code>ID</code> values are unique in the system |
| * table but may not be for dynamically created zones. |
| * @serial |
| */ |
| private String ID; |
| |
| /** |
| * Cached {@link ZoneId} for this TimeZone |
| */ |
| private transient ZoneId zoneId; |
| |
| private static volatile TimeZone defaultTimeZone; |
| |
| static final String GMT_ID = "GMT"; |
| private static final int GMT_ID_LENGTH = 3; |
| |
| // a static TimeZone we can reference if no AppContext is in place |
| private static volatile TimeZone mainAppContextDefault; |
| |
| /** |
| * Parses a custom time zone identifier and returns a corresponding zone. |
| * This method doesn't support the RFC 822 time zone format. (e.g., +hhmm) |
| * |
| * @param id a string of the <a href="#CustomID">custom ID form</a>. |
| * @return a newly created TimeZone with the given offset and |
| * no daylight saving time, or null if the id cannot be parsed. |
| */ |
| private static final TimeZone parseCustomTimeZone(String id) { |
| int length; |
| |
| // Error if the length of id isn't long enough or id doesn't |
| // start with "GMT". |
| if ((length = id.length()) < (GMT_ID_LENGTH + 2) || |
| id.indexOf(GMT_ID) != 0) { |
| return null; |
| } |
| |
| ZoneInfo zi; |
| |
| // First, we try to find it in the cache with the given |
| // id. Even the id is not normalized, the returned ZoneInfo |
| // should have its normalized id. |
| zi = ZoneInfoFile.getZoneInfo(id); |
| if (zi != null) { |
| return zi; |
| } |
| |
| int index = GMT_ID_LENGTH; |
| boolean negative = false; |
| char c = id.charAt(index++); |
| if (c == '-') { |
| negative = true; |
| } else if (c != '+') { |
| return null; |
| } |
| |
| int hours = 0; |
| int num = 0; |
| int countDelim = 0; |
| int len = 0; |
| while (index < length) { |
| c = id.charAt(index++); |
| if (c == ':') { |
| if (countDelim > 0) { |
| return null; |
| } |
| if (len > 2) { |
| return null; |
| } |
| hours = num; |
| countDelim++; |
| num = 0; |
| len = 0; |
| continue; |
| } |
| if (c < '0' || c > '9') { |
| return null; |
| } |
| num = num * 10 + (c - '0'); |
| len++; |
| } |
| if (index != length) { |
| return null; |
| } |
| if (countDelim == 0) { |
| if (len <= 2) { |
| hours = num; |
| num = 0; |
| } else { |
| hours = num / 100; |
| num %= 100; |
| } |
| } else { |
| if (len != 2) { |
| return null; |
| } |
| } |
| if (hours > 23 || num > 59) { |
| return null; |
| } |
| int gmtOffset = (hours * 60 + num) * 60 * 1000; |
| |
| if (gmtOffset == 0) { |
| zi = ZoneInfoFile.getZoneInfo(GMT_ID); |
| if (negative) { |
| zi.setID("GMT-00:00"); |
| } else { |
| zi.setID("GMT+00:00"); |
| } |
| } else { |
| zi = ZoneInfoFile.getCustomTimeZone(id, negative ? -gmtOffset : gmtOffset); |
| } |
| return zi; |
| } |
| } |
