|
|
The ZoneInfo.java Java example source code
/*
* Copyright (c) 2000, 2013, 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.
*/
package sun.util.calendar;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.lang.ref.SoftReference;
import java.security.AccessController;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.SimpleTimeZone;
import java.util.TimeZone;
/**
* <code>ZoneInfo is an implementation subclass of {@link
* java.util.TimeZone TimeZone} that represents GMT offsets and
* daylight saving time transitions of a time zone.
* <p>
* The daylight saving time transitions are described in the {@link
* #transitions transitions} table consisting of a chronological
* sequence of transitions of GMT offset and/or daylight saving time
* changes. Since all transitions are represented in UTC, in theory,
* <code>ZoneInfo can be used with any calendar systems except
* for the {@link #getOffset(int,int,int,int,int,int) getOffset}
* method that takes Gregorian calendar date fields.
* <p>
* This table covers transitions from 1900 until 2037 (as of version
* 1.4), Before 1900, it assumes that there was no daylight saving
* time and the <code>getOffset methods always return the
* {@link #getRawOffset} value. No Local Mean Time is supported. If a
* specified date is beyond the transition table and this time zone is
* supposed to observe daylight saving time in 2037, it delegates
* operations to a {@link java.util.SimpleTimeZone SimpleTimeZone}
* object created using the daylight saving time schedule as of 2037.
* <p>
* The date items, transitions, GMT offset(s), etc. are read from a database
* file. See {@link ZoneInfoFile} for details.
* @see java.util.SimpleTimeZone
* @since 1.4
*/
public class ZoneInfo extends TimeZone {
private static final int UTC_TIME = 0;
private static final int STANDARD_TIME = 1;
private static final int WALL_TIME = 2;
private static final long OFFSET_MASK = 0x0fL;
private static final long DST_MASK = 0xf0L;
private static final int DST_NSHIFT = 4;
// this bit field is reserved for abbreviation support
private static final long ABBR_MASK = 0xf00L;
private static final int TRANSITION_NSHIFT = 12;
private static final CalendarSystem gcal = CalendarSystem.getGregorianCalendar();
/**
* The raw GMT offset in milliseconds between this zone and GMT.
* Negative offsets are to the west of Greenwich. To obtain local
* <em>standard time, add the offset to GMT time.
* @serial
*/
private int rawOffset;
/**
* Difference in milliseconds from the original GMT offset in case
* the raw offset value has been modified by calling {@link
* #setRawOffset}. The initial value is 0.
* @serial
*/
private int rawOffsetDiff = 0;
/**
* A CRC32 value of all pairs of transition time (in milliseconds
* in <code>long) in local time and its GMT offset (in
* seconds in <code>int) in the chronological order. Byte
* values of each <code>long and int are taken
* in the big endian order (i.e., MSB to LSB).
* @serial
*/
private int checksum;
/**
* The amount of time in milliseconds saved during daylight saving
* time. If <code>useDaylight is false, this value is 0.
* @serial
*/
private int dstSavings;
/**
* This array describes transitions of GMT offsets of this time
* zone, including both raw offset changes and daylight saving
* time changes.
* A long integer consists of four bit fields.
* <ul>
* <li>The most significant 52-bit field represents transition
* time in milliseconds from Gregorian January 1 1970, 00:00:00
* GMT.</li>
* <li>The next 4-bit field is reserved and must be 0.
* <li>The next 4-bit field is an index value to {@link #offsets
* offsets[]} for the amount of daylight saving at the
* transition. If this value is zero, it means that no daylight
* saving, not the index value zero.</li>
* <li>The least significant 4-bit field is an index value to
* {@link #offsets offsets[]} for <em>total GMT offset at the
* transition.</li>
* </ul>
* If this time zone doesn't observe daylight saving time and has
* never changed any GMT offsets in the past, this value is null.
* @serial
*/
private long[] transitions;
/**
* This array holds all unique offset values in
* milliseconds. Index values to this array are stored in the
* transitions array elements.
* @serial
*/
private int[] offsets;
/**
* SimpleTimeZone parameter values. It has to have either 8 for
* {@link java.util.SimpleTimeZone#SimpleTimeZone(int, String,
* int, int , int , int , int , int , int , int , int) the
* 11-argument SimpleTimeZone constructor} or 10 for {@link
* java.util.SimpleTimeZone#SimpleTimeZone(int, String, int, int,
* int , int , int , int , int , int , int, int, int) the
* 13-argument SimpleTimeZone constructor} parameters.
* @serial
*/
private int[] simpleTimeZoneParams;
/**
* True if the raw GMT offset value would change after the time
* zone data has been generated; false, otherwise. The default
* value is false.
* @serial
*/
private boolean willGMTOffsetChange = false;
/**
* True if the object has been modified after its instantiation.
*/
transient private boolean dirty = false;
private static final long serialVersionUID = 2653134537216586139L;
/**
* A constructor.
*/
public ZoneInfo() {
}
/**
* A Constructor for CustomID.
*/
public ZoneInfo(String ID, int rawOffset) {
this(ID, rawOffset, 0, 0, null, null, null, false);
}
/**
* Constructs a ZoneInfo instance.
*
* @param ID time zone name
* @param rawOffset GMT offset in milliseconds
* @param dstSavings daylight saving value in milliseconds or 0
* (zero) if this time zone doesn't observe Daylight Saving Time.
* @param checksum CRC32 value with all transitions table entry
* values
* @param transitions transition table
* @param offsets offset value table
* @param simpleTimeZoneParams parameter values for constructing
* SimpleTimeZone
* @param willGMTOffsetChange the value of willGMTOffsetChange
*/
ZoneInfo(String ID,
int rawOffset,
int dstSavings,
int checksum,
long[] transitions,
int[] offsets,
int[] simpleTimeZoneParams,
boolean willGMTOffsetChange) {
setID(ID);
this.rawOffset = rawOffset;
this.dstSavings = dstSavings;
this.checksum = checksum;
this.transitions = transitions;
this.offsets = offsets;
this.simpleTimeZoneParams = simpleTimeZoneParams;
this.willGMTOffsetChange = willGMTOffsetChange;
}
/**
* Returns the difference in milliseconds between local time and UTC
* of given time, taking into account both the raw offset and the
* effect of daylight savings.
*
* @param date the milliseconds in UTC
* @return the milliseconds to add to UTC to get local wall time
*/
public int getOffset(long date) {
return getOffsets(date, null, UTC_TIME);
}
public int getOffsets(long utc, int[] offsets) {
return getOffsets(utc, offsets, UTC_TIME);
}
public int getOffsetsByStandard(long standard, int[] offsets) {
return getOffsets(standard, offsets, STANDARD_TIME);
}
public int getOffsetsByWall(long wall, int[] offsets) {
return getOffsets(wall, offsets, WALL_TIME);
}
private int getOffsets(long date, int[] offsets, int type) {
// if dst is never observed, there is no transition.
if (transitions == null) {
int offset = getLastRawOffset();
if (offsets != null) {
offsets[0] = offset;
offsets[1] = 0;
}
return offset;
}
date -= rawOffsetDiff;
int index = getTransitionIndex(date, type);
// prior to the transition table, returns the raw offset.
// FIXME: should support LMT.
if (index < 0) {
int offset = getLastRawOffset();
if (offsets != null) {
offsets[0] = offset;
offsets[1] = 0;
}
return offset;
}
if (index < transitions.length) {
long val = transitions[index];
int offset = this.offsets[(int)(val & OFFSET_MASK)] + rawOffsetDiff;
if (offsets != null) {
int dst = (int)((val >>> DST_NSHIFT) & 0xfL);
int save = (dst == 0) ? 0 : this.offsets[dst];
offsets[0] = offset - save;
offsets[1] = save;
}
return offset;
}
// beyond the transitions, delegate to SimpleTimeZone if there
// is a rule; otherwise, return rawOffset.
SimpleTimeZone tz = getLastRule();
if (tz != null) {
int rawoffset = tz.getRawOffset();
long msec = date;
if (type != UTC_TIME) {
msec -= rawOffset;
}
int dstoffset = tz.getOffset(msec) - rawOffset;
// Check if it's in a standard-to-daylight transition.
if (dstoffset > 0 && tz.getOffset(msec - dstoffset) == rawoffset) {
dstoffset = 0;
}
if (offsets != null) {
offsets[0] = rawoffset;
offsets[1] = dstoffset;
}
return rawoffset + dstoffset;
}
int offset = getLastRawOffset();
if (offsets != null) {
offsets[0] = offset;
offsets[1] = 0;
}
return offset;
}
private int getTransitionIndex(long date, int type) {
int low = 0;
int high = transitions.length - 1;
while (low <= high) {
int mid = (low + high) / 2;
long val = transitions[mid];
long midVal = val >> TRANSITION_NSHIFT; // sign extended
if (type != UTC_TIME) {
midVal += offsets[(int)(val & OFFSET_MASK)]; // wall time
}
if (type == STANDARD_TIME) {
int dstIndex = (int)((val >>> DST_NSHIFT) & 0xfL);
if (dstIndex != 0) {
midVal -= offsets[dstIndex]; // make it standard time
}
}
if (midVal < date) {
low = mid + 1;
} else if (midVal > date) {
high = mid - 1;
} else {
return mid;
}
}
// if beyond the transitions, returns that index.
if (low >= transitions.length) {
return low;
}
return low - 1;
}
/**
* Returns the difference in milliseconds between local time and
* UTC, taking into account both the raw offset and the effect of
* daylight savings, for the specified date and time. This method
* assumes that the start and end month are distinct. This method
* assumes a Gregorian calendar for calculations.
* <p>
* <em>Note: In general, clients should use
* {@link Calendar#ZONE_OFFSET Calendar.get(ZONE_OFFSET)} +
* {@link Calendar#DST_OFFSET Calendar.get(DST_OFFSET)}
* instead of calling this method.</em>
*
* @param era The era of the given date. The value must be either
* GregorianCalendar.AD or GregorianCalendar.BC.
* @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 millis The milliseconds in day in <em>standard local time.
* @return The milliseconds to add to UTC to get local time.
*/
public int getOffset(int era, int year, int month, int day,
int dayOfWeek, int milliseconds) {
if (milliseconds < 0 || milliseconds >= AbstractCalendar.DAY_IN_MILLIS) {
throw new IllegalArgumentException();
}
if (era == java.util.GregorianCalendar.BC) { // BC
year = 1 - year;
} else if (era != java.util.GregorianCalendar.AD) {
throw new IllegalArgumentException();
}
CalendarDate date = gcal.newCalendarDate(null);
date.setDate(year, month + 1, day);
if (gcal.validate(date) == false) {
throw new IllegalArgumentException();
}
// bug-for-bug compatible argument checking
if (dayOfWeek < java.util.GregorianCalendar.SUNDAY
|| dayOfWeek > java.util.GregorianCalendar.SATURDAY) {
throw new IllegalArgumentException();
}
if (transitions == null) {
return getLastRawOffset();
}
long dateInMillis = gcal.getTime(date) + milliseconds;
dateInMillis -= (long) rawOffset; // make it UTC
return getOffsets(dateInMillis, null, UTC_TIME);
}
/**
* Sets the base time zone offset from GMT. This operation
* modifies all the transitions of this ZoneInfo object, including
* historical ones, if applicable.
*
* @param offsetMillis the base time zone offset to GMT.
* @see getRawOffset
*/
public synchronized void setRawOffset(int offsetMillis) {
if (offsetMillis == rawOffset + rawOffsetDiff) {
return;
}
rawOffsetDiff = offsetMillis - rawOffset;
if (lastRule != null) {
lastRule.setRawOffset(offsetMillis);
}
dirty = true;
}
/**
* Returns the GMT offset of the current date. This GMT offset
* value is not modified during Daylight Saving Time.
*
* @return the GMT offset value in milliseconds to add to UTC time
* to get local standard time
*/
public int getRawOffset() {
if (!willGMTOffsetChange) {
return rawOffset + rawOffsetDiff;
}
int[] offsets = new int[2];
getOffsets(System.currentTimeMillis(), offsets, UTC_TIME);
return offsets[0];
}
public boolean isDirty() {
return dirty;
}
private int getLastRawOffset() {
return rawOffset + rawOffsetDiff;
}
/**
* Queries if this time zone uses Daylight Saving Time in the last known rule.
*/
public boolean useDaylightTime() {
return (simpleTimeZoneParams != null);
}
@Override
public boolean observesDaylightTime() {
if (simpleTimeZoneParams != null) {
return true;
}
if (transitions == null) {
return false;
}
// Look up the transition table to see if it's in DST right
// now or if there's any standard-to-daylight transition at
// any future.
long utc = System.currentTimeMillis() - rawOffsetDiff;
int index = getTransitionIndex(utc, UTC_TIME);
// before transitions in the transition table
if (index < 0) {
return false;
}
// the time is in the table range.
for (int i = index; i < transitions.length; i++) {
if ((transitions[i] & DST_MASK) != 0) {
return true;
}
}
// No further DST is observed.
return false;
}
/**
* Queries if the specified date is in Daylight Saving Time.
*/
public boolean inDaylightTime(Date date) {
if (date == null) {
throw new NullPointerException();
}
if (transitions == null) {
return false;
}
long utc = date.getTime() - rawOffsetDiff;
int index = getTransitionIndex(utc, UTC_TIME);
// before transitions in the transition table
if (index < 0) {
return false;
}
// the time is in the table range.
if (index < transitions.length) {
return (transitions[index] & DST_MASK) != 0;
}
// beyond the transition table
SimpleTimeZone tz = getLastRule();
if (tz != null) {
return tz.inDaylightTime(date);
}
return false;
}
/**
* Returns the amount of time in milliseconds that the clock is advanced
* during daylight saving time is in effect in its last daylight saving time rule.
*
* @return the number of milliseconds the time is advanced with respect to
* standard time when daylight saving time is in effect.
*/
public int getDSTSavings() {
return dstSavings;
}
// /**
// * @return the last year in the transition table or -1 if this
// * time zone doesn't observe any daylight saving time.
// */
// public int getMaxTransitionYear() {
// if (transitions == null) {
// return -1;
// }
// long val = transitions[transitions.length - 1];
// int offset = this.offsets[(int)(val & OFFSET_MASK)] + rawOffsetDiff;
// val = (val >> TRANSITION_NSHIFT) + offset;
// CalendarDate lastDate = Gregorian.getCalendarDate(val);
// return lastDate.getYear();
// }
/**
* Returns a string representation of this time zone.
* @return the string
*/
public String toString() {
return getClass().getName() +
"[id=\"" + getID() + "\"" +
",offset=" + getLastRawOffset() +
",dstSavings=" + dstSavings +
",useDaylight=" + useDaylightTime() +
",transitions=" + ((transitions != null) ? transitions.length : 0) +
",lastRule=" + (lastRule == null ? getLastRuleInstance() : lastRule) +
"]";
}
/**
* Gets all available IDs supported in the Java run-time.
*
* @return an array of time zone IDs.
*/
public static String[] getAvailableIDs() {
return ZoneInfoFile.getZoneIds();
}
/**
* Gets all available IDs that have the same value as the
* specified raw GMT offset.
*
* @param rawOffset the GMT offset in milliseconds. This
* value should not include any daylight saving time.
*
* @return an array of time zone IDs.
*/
public static String[] getAvailableIDs(int rawOffset) {
return ZoneInfoFile.getZoneIds(rawOffset);
}
/**
* Gets the ZoneInfo for the given ID.
*
* @param ID the ID for a ZoneInfo. See TimeZone for detail.
*
* @return the specified ZoneInfo object, or null if there is no
* time zone of the ID.
*/
public static TimeZone getTimeZone(String ID) {
return ZoneInfoFile.getZoneInfo(ID);
}
private transient SimpleTimeZone lastRule;
/**
* Returns a SimpleTimeZone object representing the last GMT
* offset and DST schedule or null if this time zone doesn't
* observe DST.
*/
private synchronized SimpleTimeZone getLastRule() {
if (lastRule == null) {
lastRule = getLastRuleInstance();
}
return lastRule;
}
/**
* Returns a SimpleTimeZone object that represents the last
* known daylight saving time rules.
*
* @return a SimpleTimeZone object or null if this time zone
* doesn't observe DST.
*/
public SimpleTimeZone getLastRuleInstance() {
if (simpleTimeZoneParams == null) {
return null;
}
if (simpleTimeZoneParams.length == 10) {
return new SimpleTimeZone(getLastRawOffset(), getID(),
simpleTimeZoneParams[0],
simpleTimeZoneParams[1],
simpleTimeZoneParams[2],
simpleTimeZoneParams[3],
simpleTimeZoneParams[4],
simpleTimeZoneParams[5],
simpleTimeZoneParams[6],
simpleTimeZoneParams[7],
simpleTimeZoneParams[8],
simpleTimeZoneParams[9],
dstSavings);
}
return new SimpleTimeZone(getLastRawOffset(), getID(),
simpleTimeZoneParams[0],
simpleTimeZoneParams[1],
simpleTimeZoneParams[2],
simpleTimeZoneParams[3],
simpleTimeZoneParams[4],
simpleTimeZoneParams[5],
simpleTimeZoneParams[6],
simpleTimeZoneParams[7],
dstSavings);
}
/**
* Returns a copy of this <code>ZoneInfo.
*/
public Object clone() {
ZoneInfo zi = (ZoneInfo) super.clone();
zi.lastRule = null;
return zi;
}
/**
* Returns a hash code value calculated from the GMT offset and
* transitions.
* @return a hash code of this time zone
*/
public int hashCode() {
return getLastRawOffset() ^ checksum;
}
/**
* Compares the equity of two ZoneInfo objects.
*
* @param obj the object to be compared with
* @return true if given object is same as this ZoneInfo object,
* false otherwise.
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof ZoneInfo)) {
return false;
}
ZoneInfo that = (ZoneInfo) obj;
return (getID().equals(that.getID())
&& (getLastRawOffset() == that.getLastRawOffset())
&& (checksum == that.checksum));
}
/**
* Returns true if this zone has the same raw GMT offset value and
* transition table as another zone info. If the specified
* TimeZone object is not a ZoneInfo instance, this method returns
* true if the specified TimeZone object has the same raw GMT
* offset value with no daylight saving time.
*
* @param other the ZoneInfo object to be compared with
* @return true if the given <code>TimeZone has the same
* GMT offset and transition information; false, otherwise.
*/
public boolean hasSameRules(TimeZone other) {
if (this == other) {
return true;
}
if (other == null) {
return false;
}
if (!(other instanceof ZoneInfo)) {
if (getRawOffset() != other.getRawOffset()) {
return false;
}
// if both have the same raw offset and neither observes
// DST, they have the same rule.
if ((transitions == null)
&& (useDaylightTime() == false)
&& (other.useDaylightTime() == false)) {
return true;
}
return false;
}
if (getLastRawOffset() != ((ZoneInfo)other).getLastRawOffset()) {
return false;
}
return (checksum == ((ZoneInfo)other).checksum);
}
/**
* Returns a Map from alias time zone IDs to their standard
* time zone IDs.
*
* @return the Map that holds the mappings from alias time zone IDs
* to their standard time zone IDs, or null if
* <code>ZoneInfoMappings file is not available.
*/
public static Map<String, String> getAliasTable() {
return ZoneInfoFile.getAliasMap();
}
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
// We don't know how this object from 1.4.x or earlier has
// been mutated. So it should always be marked as `dirty'.
dirty = true;
}
}
Other Java examples (source code examples)
Here is a short list of links related to this Java ZoneInfo.java source code file:
|
The search page
Other Java source code examples at this package level
Click here to learn more about this project
