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With inspiration from other libraries
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 2007-2015, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.util;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import java.util.MissingResourceException;
import java.util.StringTokenizer;
import com.ibm.icu.impl.Grego;
/**
* VTimeZone is a class implementing RFC2445 VTIMEZONE. You can create a
* VTimeZone instance from a time zone ID supported by TimeZone.
* With the VTimeZone instance created from the ID, you can write out the rule
* in RFC2445 VTIMEZONE format. Also, you can create a VTimeZone instance
* from RFC2445 VTIMEZONE data stream, which allows you to calculate time
* zone offset by the rules defined by the data.
*
* Note: The consumer of this class reading or writing VTIMEZONE data is responsible to
* decode or encode Non-ASCII text. Methods reading/writing VTIMEZONE data in this class
* do nothing with MIME encoding.
*
* @stable ICU 3.8
*/
public class VTimeZone extends BasicTimeZone {
private static final long serialVersionUID = -6851467294127795902L;
/**
* Create a VTimeZone instance by the time zone ID.
*
* @param tzid The time zone ID, such as America/New_York
* @return A VTimeZone initialized by the time zone ID, or null
* when the ID is unknown.
*
* @stable ICU 3.8
*/
public static VTimeZone create(String tzid) {
BasicTimeZone basicTimeZone = TimeZone.getFrozenICUTimeZone(tzid, true);
if (basicTimeZone == null) {
return null;
}
VTimeZone vtz = new VTimeZone(tzid);
vtz.tz = (BasicTimeZone) basicTimeZone.cloneAsThawed();
vtz.olsonzid = vtz.tz.getID();
return vtz;
}
/**
* Create a VTimeZone instance by RFC2445 VTIMEZONE data.
*
* @param reader The Reader for VTIMEZONE data input stream
* @return A VTimeZone initialized by the VTIMEZONE data or
* null if failed to load the rule from the VTIMEZONE data.
*
* @stable ICU 3.8
*/
public static VTimeZone create(Reader reader) {
VTimeZone vtz = new VTimeZone();
if (vtz.load(reader)) {
return vtz;
}
return null;
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public int getOffset(int era, int year, int month, int day, int dayOfWeek,
int milliseconds) {
return tz.getOffset(era, year, month, day, dayOfWeek, milliseconds);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public void getOffset(long date, boolean local, int[] offsets) {
tz.getOffset(date, local, offsets);
}
/**
* {@inheritDoc}
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
@Override
public void getOffsetFromLocal(long date,
int nonExistingTimeOpt, int duplicatedTimeOpt, int[] offsets) {
tz.getOffsetFromLocal(date, nonExistingTimeOpt, duplicatedTimeOpt, offsets);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public int getRawOffset() {
return tz.getRawOffset();
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public boolean inDaylightTime(Date date) {
return tz.inDaylightTime(date);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public void setRawOffset(int offsetMillis) {
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen VTimeZone instance.");
}
tz.setRawOffset(offsetMillis);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public boolean useDaylightTime() {
return tz.useDaylightTime();
}
/**
* {@inheritDoc}
* @stable ICU 49
*/
@Override
public boolean observesDaylightTime() {
return tz.observesDaylightTime();
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public boolean hasSameRules(TimeZone other) {
if (this == other) {
return true;
}
if (other instanceof VTimeZone) {
return tz.hasSameRules(((VTimeZone)other).tz);
}
return tz.hasSameRules(other);
}
/**
* Gets the RFC2445 TZURL property value. When a VTimeZone instance was created from
* VTIMEZONE data, the value is set by the TZURL property value in the data. Otherwise,
* the initial value is null.
*
* @return The RFC2445 TZURL property value
*
* @stable ICU 3.8
*/
public String getTZURL() {
return tzurl;
}
/**
* Sets the RFC2445 TZURL property value.
*
* @param url The TZURL property value.
*
* @stable ICU 3.8
*/
public void setTZURL(String url) {
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen VTimeZone instance.");
}
tzurl = url;
}
/**
* Gets the RFC2445 LAST-MODIFIED property value. When a VTimeZone instance was created
* from VTIMEZONE data, the value is set by the LAST-MODIFIED property value in the data.
* Otherwise, the initial value is null.
*
* @return The Date represents the RFC2445 LAST-MODIFIED date.
*
* @stable ICU 3.8
*/
public Date getLastModified() {
return lastmod;
}
/**
* Sets the date used for RFC2445 LAST-MODIFIED property value.
*
* @param date The Date object represents the date for RFC2445 LAST-MODIFIED property value.
*
* @stable ICU 3.8
*/
public void setLastModified(Date date) {
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen VTimeZone instance.");
}
lastmod = date;
}
/**
* Writes RFC2445 VTIMEZONE data for this time zone
*
* @param writer A Writer used for the output
* @throws IOException If there were problems creating a buffered writer or writing to it.
*
* @stable ICU 3.8
*/
public void write(Writer writer) throws IOException {
BufferedWriter bw = new BufferedWriter(writer);
if (vtzlines != null) {
for (String line : vtzlines) {
if (line.startsWith(ICAL_TZURL + COLON)) {
if (tzurl != null) {
bw.write(ICAL_TZURL);
bw.write(COLON);
bw.write(tzurl);
bw.write(NEWLINE);
}
} else if (line.startsWith(ICAL_LASTMOD + COLON)) {
if (lastmod != null) {
bw.write(ICAL_LASTMOD);
bw.write(COLON);
bw.write(getUTCDateTimeString(lastmod.getTime()));
bw.write(NEWLINE);
}
} else {
bw.write(line);
bw.write(NEWLINE);
}
}
bw.flush();
} else {
String[] customProperties = null;
if (olsonzid != null && ICU_TZVERSION != null) {
customProperties = new String[1];
customProperties[0] = ICU_TZINFO_PROP + COLON + olsonzid + "[" + ICU_TZVERSION + "]";
}
writeZone(writer, tz, customProperties);
}
}
/**
* Writes RFC2445 VTIMEZONE data applicable for dates after
* the specified start time.
*
* @param writer The Writer used for the output
* @param start The start time
*
* @throws IOException If there were problems reading and writing to the writer.
*
* @stable ICU 3.8
*/
public void write(Writer writer, long start) throws IOException {
// Extract rules applicable to dates after the start time
TimeZoneRule[] rules = tz.getTimeZoneRules(start);
// Create a RuleBasedTimeZone with the subset rule
RuleBasedTimeZone rbtz = new RuleBasedTimeZone(tz.getID(), (InitialTimeZoneRule)rules[0]);
for (int i = 1; i < rules.length; i++) {
rbtz.addTransitionRule(rules[i]);
}
String[] customProperties = null;
if (olsonzid != null && ICU_TZVERSION != null) {
customProperties = new String[1];
customProperties[0] = ICU_TZINFO_PROP + COLON + olsonzid + "[" + ICU_TZVERSION +
"/Partial@" + start + "]";
}
writeZone(writer, rbtz, customProperties);
}
/**
* Writes RFC2445 VTIMEZONE data applicable near the specified date.
* Some common iCalendar implementations can only handle a single time
* zone property or a pair of standard and daylight time properties using
* BYDAY rule with day of week (such as BYDAY=1SUN). This method produce
* the VTIMEZONE data which can be handled these implementations. The rules
* produced by this method can be used only for calculating time zone offset
* around the specified date.
*
* @param writer The Writer used for the output
* @param time The date
*
* @throws IOException If there were problems reading or writing to the writer.
*
* @stable ICU 3.8
*/
public void writeSimple(Writer writer, long time) throws IOException {
// Extract simple rules
TimeZoneRule[] rules = tz.getSimpleTimeZoneRulesNear(time);
// Create a RuleBasedTimeZone with the subset rule
RuleBasedTimeZone rbtz = new RuleBasedTimeZone(tz.getID(), (InitialTimeZoneRule)rules[0]);
for (int i = 1; i < rules.length; i++) {
rbtz.addTransitionRule(rules[i]);
}
String[] customProperties = null;
if (olsonzid != null && ICU_TZVERSION != null) {
customProperties = new String[1];
customProperties[0] = ICU_TZINFO_PROP + COLON + olsonzid + "[" + ICU_TZVERSION +
"/Simple@" + time + "]";
}
writeZone(writer, rbtz, customProperties);
}
// BasicTimeZone methods
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public TimeZoneTransition getNextTransition(long base, boolean inclusive) {
return tz.getNextTransition(base, inclusive);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public TimeZoneTransition getPreviousTransition(long base, boolean inclusive) {
return tz.getPreviousTransition(base, inclusive);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public boolean hasEquivalentTransitions(TimeZone other, long start, long end) {
if (this == other) {
return true;
}
return tz.hasEquivalentTransitions(other, start, end);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public TimeZoneRule[] getTimeZoneRules() {
return tz.getTimeZoneRules();
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public TimeZoneRule[] getTimeZoneRules(long start) {
return tz.getTimeZoneRules(start);
}
/**
* {@inheritDoc}
* @stable ICU 3.8
*/
@Override
public Object clone() {
if (isFrozen()) {
return this;
}
return cloneAsThawed();
}
// private stuff ------------------------------------------------------
private BasicTimeZone tz;
private List vtzlines;
private String olsonzid = null;
private String tzurl = null;
private Date lastmod = null;
private static String ICU_TZVERSION;
private static final String ICU_TZINFO_PROP = "X-TZINFO";
// Default DST savings
private static final int DEF_DSTSAVINGS = 60*60*1000; // 1 hour
// Default time start
private static final long DEF_TZSTARTTIME = 0;
// minimum/max
private static final long MIN_TIME = Long.MIN_VALUE;
private static final long MAX_TIME = Long.MAX_VALUE;
// Symbol characters used by RFC2445 VTIMEZONE
private static final String COLON = ":";
private static final String SEMICOLON = ";";
private static final String EQUALS_SIGN = "=";
private static final String COMMA = ",";
private static final String NEWLINE = "\r\n"; // CRLF
// RFC2445 VTIMEZONE tokens
private static final String ICAL_BEGIN_VTIMEZONE = "BEGIN:VTIMEZONE";
private static final String ICAL_END_VTIMEZONE = "END:VTIMEZONE";
private static final String ICAL_BEGIN = "BEGIN";
private static final String ICAL_END = "END";
private static final String ICAL_VTIMEZONE = "VTIMEZONE";
private static final String ICAL_TZID = "TZID";
private static final String ICAL_STANDARD = "STANDARD";
private static final String ICAL_DAYLIGHT = "DAYLIGHT";
private static final String ICAL_DTSTART = "DTSTART";
private static final String ICAL_TZOFFSETFROM = "TZOFFSETFROM";
private static final String ICAL_TZOFFSETTO = "TZOFFSETTO";
private static final String ICAL_RDATE = "RDATE";
private static final String ICAL_RRULE = "RRULE";
private static final String ICAL_TZNAME = "TZNAME";
private static final String ICAL_TZURL = "TZURL";
private static final String ICAL_LASTMOD = "LAST-MODIFIED";
private static final String ICAL_FREQ = "FREQ";
private static final String ICAL_UNTIL = "UNTIL";
private static final String ICAL_YEARLY = "YEARLY";
private static final String ICAL_BYMONTH = "BYMONTH";
private static final String ICAL_BYDAY = "BYDAY";
private static final String ICAL_BYMONTHDAY = "BYMONTHDAY";
private static final String[] ICAL_DOW_NAMES =
{"SU", "MO", "TU", "WE", "TH", "FR", "SA"};
// Month length in regular year
private static final int[] MONTHLENGTH = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static {
// Initialize ICU_TZVERSION
try {
ICU_TZVERSION = TimeZone.getTZDataVersion();
} catch (MissingResourceException e) {
///CLOVER:OFF
ICU_TZVERSION = null;
///CLOVER:ON
}
}
/* Hide the constructor */
private VTimeZone() {
}
private VTimeZone(String tzid) {
super(tzid);
}
/*
* Read the input stream to locate the VTIMEZONE block and
* parse the contents to initialize this VTimeZone object.
* The reader skips other RFC2445 message headers. After
* the parse is completed, the reader points at the beginning
* of the header field just after the end of VTIMEZONE block.
* When VTIMEZONE block is found and this object is successfully
* initialized by the rules described in the data, this method
* returns true. Otherwise, returns false.
*/
private boolean load(Reader reader) {
// Read VTIMEZONE block into string array
try {
vtzlines = new LinkedList();
boolean eol = false;
boolean start = false;
boolean success = false;
StringBuilder line = new StringBuilder();
while (true) {
int ch = reader.read();
if (ch == -1) {
// end of file
if (start && line.toString().startsWith(ICAL_END_VTIMEZONE)) {
vtzlines.add(line.toString());
success = true;
}
break;
}
if (ch == 0x0D) {
// CR, must be followed by LF by the definition in RFC2445
continue;
}
if (eol) {
if (ch != 0x09 && ch != 0x20) {
// NOT followed by TAB/SP -> new line
if (start) {
if (line.length() > 0) {
vtzlines.add(line.toString());
}
}
line.setLength(0);
if (ch != 0x0A) {
line.append((char)ch);
}
}
eol = false;
} else {
if (ch == 0x0A) {
// LF
eol = true;
if (start) {
if (line.toString().startsWith(ICAL_END_VTIMEZONE)) {
vtzlines.add(line.toString());
success = true;
break;
}
} else {
if (line.toString().startsWith(ICAL_BEGIN_VTIMEZONE)) {
vtzlines.add(line.toString());
line.setLength(0);
start = true;
eol = false;
}
}
} else {
line.append((char)ch);
}
}
}
if (!success) {
return false;
}
} catch (IOException ioe) {
///CLOVER:OFF
return false;
///CLOVER:ON
}
return parse();
}
// parser state
private static final int INI = 0; // Initial state
private static final int VTZ = 1; // In VTIMEZONE
private static final int TZI = 2; // In STANDARD or DAYLIGHT
private static final int ERR = 3; // Error state
/*
* Parse VTIMEZONE data and create a RuleBasedTimeZone
*/
private boolean parse() {
///CLOVER:OFF
if (vtzlines == null || vtzlines.size() == 0) {
return false;
}
///CLOVER:ON
// timezone ID
String tzid = null;
int state = INI;
boolean dst = false; // current zone type
String from = null; // current zone from offset
String to = null; // current zone offset
String tzname = null; // current zone name
String dtstart = null; // current zone starts
boolean isRRULE = false; // true if the rule is described by RRULE
List dates = null; // list of RDATE or RRULE strings
List rules = new ArrayList(); // rule list
int initialRawOffset = 0; // initial offset
int initialDSTSavings = 0; // initial offset
long firstStart = MAX_TIME; // the earliest rule start time
for (String line : vtzlines) {
int valueSep = line.indexOf(COLON);
if (valueSep < 0) {
continue;
}
String name = line.substring(0, valueSep);
String value = line.substring(valueSep + 1);
switch (state) {
case INI:
if (name.equals(ICAL_BEGIN) && value.equals(ICAL_VTIMEZONE)) {
state = VTZ;
}
break;
case VTZ:
if (name.equals(ICAL_TZID)) {
tzid = value;
} else if (name.equals(ICAL_TZURL)) {
tzurl = value;
} else if (name.equals(ICAL_LASTMOD)) {
// Always in 'Z' format, so the offset argument for the parse method
// can be any value.
lastmod = new Date(parseDateTimeString(value, 0));
} else if (name.equals(ICAL_BEGIN)) {
boolean isDST = value.equals(ICAL_DAYLIGHT);
if (value.equals(ICAL_STANDARD) || isDST) {
// tzid must be ready at this point
if (tzid == null) {
state = ERR;
break;
}
// initialize current zone properties
dates = null;
isRRULE = false;
from = null;
to = null;
tzname = null;
dst = isDST;
state = TZI;
} else {
// BEGIN property other than STANDARD/DAYLIGHT
// must not be there.
state = ERR;
break;
}
} else if (name.equals(ICAL_END) /* && value.equals(ICAL_VTIMEZONE) */) {
break;
}
break;
case TZI:
if (name.equals(ICAL_DTSTART)) {
dtstart = value;
} else if (name.equals(ICAL_TZNAME)) {
tzname = value;
} else if (name.equals(ICAL_TZOFFSETFROM)) {
from = value;
} else if (name.equals(ICAL_TZOFFSETTO)) {
to = value;
} else if (name.equals(ICAL_RDATE)) {
// RDATE mixed with RRULE is not supported
if (isRRULE) {
state = ERR;
break;
}
if (dates == null) {
dates = new LinkedList();
}
// RDATE value may contain multiple date delimited
// by comma
StringTokenizer st = new StringTokenizer(value, COMMA);
while (st.hasMoreTokens()) {
String date = st.nextToken();
dates.add(date);
}
} else if (name.equals(ICAL_RRULE)) {
// RRULE mixed with RDATE is not supported
if (!isRRULE && dates != null) {
state = ERR;
break;
} else if (dates == null) {
dates = new LinkedList();
}
isRRULE = true;
dates.add(value);
} else if (name.equals(ICAL_END)) {
// Mandatory properties
if (dtstart == null || from == null || to == null) {
state = ERR;
break;
}
// if tzname is not available, create one from tzid
if (tzname == null) {
tzname = getDefaultTZName(tzid, dst);
}
// create a time zone rule
TimeZoneRule rule = null;
int fromOffset = 0;
int toOffset = 0;
int rawOffset = 0;
int dstSavings = 0;
long start = 0;
try {
// Parse TZOFFSETFROM/TZOFFSETTO
fromOffset = offsetStrToMillis(from);
toOffset = offsetStrToMillis(to);
if (dst) {
// If daylight, use the previous offset as rawoffset if positive
if (toOffset - fromOffset > 0) {
rawOffset = fromOffset;
dstSavings = toOffset - fromOffset;
} else {
// This is rare case.. just use 1 hour DST savings
rawOffset = toOffset - DEF_DSTSAVINGS;
dstSavings = DEF_DSTSAVINGS;
}
} else {
rawOffset = toOffset;
dstSavings = 0;
}
// start time
start = parseDateTimeString(dtstart, fromOffset);
// Create the rule
Date actualStart = null;
if (isRRULE) {
rule = createRuleByRRULE(tzname, rawOffset, dstSavings, start, dates, fromOffset);
} else {
rule = createRuleByRDATE(tzname, rawOffset, dstSavings, start, dates, fromOffset);
}
if (rule != null) {
actualStart = rule.getFirstStart(fromOffset, 0);
if (actualStart.getTime() < firstStart) {
// save from offset information for the earliest rule
firstStart = actualStart.getTime();
// If this is STD, assume the time before this transtion
// is DST when the difference is 1 hour. This might not be
// accurate, but VTIMEZONE data does not have such info.
if (dstSavings > 0) {
initialRawOffset = fromOffset;
initialDSTSavings = 0;
} else {
if (fromOffset - toOffset == DEF_DSTSAVINGS) {
initialRawOffset = fromOffset - DEF_DSTSAVINGS;
initialDSTSavings = DEF_DSTSAVINGS;
} else {
initialRawOffset = fromOffset;
initialDSTSavings = 0;
}
}
}
}
} catch (IllegalArgumentException iae) {
// bad format - rule == null..
}
if (rule == null) {
state = ERR;
break;
}
rules.add(rule);
state = VTZ;
}
break;
}
if (state == ERR) {
vtzlines = null;
return false;
}
}
// Must have at least one rule
if (rules.size() == 0) {
return false;
}
// Create a initial rule
InitialTimeZoneRule initialRule = new InitialTimeZoneRule(getDefaultTZName(tzid, false),
initialRawOffset, initialDSTSavings);
// Finally, create the RuleBasedTimeZone
RuleBasedTimeZone rbtz = new RuleBasedTimeZone(tzid, initialRule);
int finalRuleIdx = -1;
int finalRuleCount = 0;
for (int i = 0; i < rules.size(); i++) {
TimeZoneRule r = rules.get(i);
if (r instanceof AnnualTimeZoneRule) {
if (((AnnualTimeZoneRule)r).getEndYear() == AnnualTimeZoneRule.MAX_YEAR) {
finalRuleCount++;
finalRuleIdx = i;
}
}
}
if (finalRuleCount > 2) {
// Too many final rules
return false;
}
if (finalRuleCount == 1) {
if (rules.size() == 1) {
// Only one final rule, only governs the initial rule,
// which is already initialized, thus, we do not need to
// add this transition rule
rules.clear();
} else {
// Normalize the final rule
AnnualTimeZoneRule finalRule = (AnnualTimeZoneRule)rules.get(finalRuleIdx);
int tmpRaw = finalRule.getRawOffset();
int tmpDST = finalRule.getDSTSavings();
// Find the last non-final rule
Date finalStart = finalRule.getFirstStart(initialRawOffset, initialDSTSavings);
Date start = finalStart;
for (int i = 0; i < rules.size(); i++) {
if (finalRuleIdx == i) {
continue;
}
TimeZoneRule r = rules.get(i);
Date lastStart = r.getFinalStart(tmpRaw, tmpDST);
if (lastStart.after(start)) {
start = finalRule.getNextStart(lastStart.getTime(),
r.getRawOffset(),
r.getDSTSavings(),
false);
}
}
TimeZoneRule newRule;
if (start == finalStart) {
// Transform this into a single transition
newRule = new TimeArrayTimeZoneRule(
finalRule.getName(),
finalRule.getRawOffset(),
finalRule.getDSTSavings(),
new long[] {finalStart.getTime()},
DateTimeRule.UTC_TIME);
} else {
// Update the end year
int fields[] = Grego.timeToFields(start.getTime(), null);
newRule = new AnnualTimeZoneRule(
finalRule.getName(),
finalRule.getRawOffset(),
finalRule.getDSTSavings(),
finalRule.getRule(),
finalRule.getStartYear(),
fields[0]);
}
rules.set(finalRuleIdx, newRule);
}
}
for (TimeZoneRule r : rules) {
rbtz.addTransitionRule(r);
}
tz = rbtz;
setID(tzid);
return true;
}
/*
* Create a default TZNAME from TZID
*/
private static String getDefaultTZName(String tzid, boolean isDST) {
if (isDST) {
return tzid + "(DST)";
}
return tzid + "(STD)";
}
/*
* Create a TimeZoneRule by the RRULE definition
*/
private static TimeZoneRule createRuleByRRULE(String tzname,
int rawOffset, int dstSavings, long start, List dates, int fromOffset) {
if (dates == null || dates.size() == 0) {
return null;
}
// Parse the first rule
String rrule = dates.get(0);
long until[] = new long[1];
int[] ruleFields = parseRRULE(rrule, until);
if (ruleFields == null) {
// Invalid RRULE
return null;
}
int month = ruleFields[0];
int dayOfWeek = ruleFields[1];
int nthDayOfWeek = ruleFields[2];
int dayOfMonth = ruleFields[3];
if (dates.size() == 1) {
// No more rules
if (ruleFields.length > 4) {
// Multiple BYMONTHDAY values
if (ruleFields.length != 10 || month == -1 || dayOfWeek == 0) {
// Only support the rule using 7 continuous days
// BYMONTH and BYDAY must be set at the same time
return null;
}
int firstDay = 31; // max possible number of dates in a month
int days[] = new int[7];
for (int i = 0; i < 7; i++) {
days[i] = ruleFields[3 + i];
// Resolve negative day numbers. A negative day number should
// not be used in February, but if we see such case, we use 28
// as the base.
days[i] = days[i] > 0 ? days[i] : MONTHLENGTH[month] + days[i] + 1;
firstDay = days[i] < firstDay ? days[i] : firstDay;
}
// Make sure days are continuous
for (int i = 1; i < 7; i++) {
boolean found = false;
for (int j = 0; j < 7; j++) {
if (days[j] == firstDay + i) {
found = true;
break;
}
}
if (!found) {
// days are not continuous
return null;
}
}
// Use DOW_GEQ_DOM rule with firstDay as the start date
dayOfMonth = firstDay;
}
} else {
// Check if BYMONTH + BYMONTHDAY + BYDAY rule with multiple RRULE lines.
// Otherwise, not supported.
if (month == -1 || dayOfWeek == 0 || dayOfMonth == 0) {
// This is not the case
return null;
}
// Parse the rest of rules if number of rules is not exceeding 7.
// We can only support 7 continuous days starting from a day of month.
if (dates.size() > 7) {
return null;
}
// Note: To check valid date range across multiple rule is a little
// bit complicated. For now, this code is not doing strict range
// checking across month boundary
int earliestMonth = month;
int daysCount = ruleFields.length - 3;
int earliestDay = 31;
for (int i = 0; i < daysCount; i++) {
int dom = ruleFields[3 + i];
dom = dom > 0 ? dom : MONTHLENGTH[month] + dom + 1;
earliestDay = dom < earliestDay ? dom : earliestDay;
}
int anotherMonth = -1;
for (int i = 1; i < dates.size(); i++) {
rrule = dates.get(i);
long[] unt = new long[1];
int[] fields = parseRRULE(rrule, unt);
// If UNTIL is newer than previous one, use the one
if (unt[0] > until[0]) {
until = unt;
}
// Check if BYMONTH + BYMONTHDAY + BYDAY rule
if (fields[0] == -1 || fields[1] == 0 || fields[3] == 0) {
return null;
}
// Count number of BYMONTHDAY
int count = fields.length - 3;
if (daysCount + count > 7) {
// We cannot support BYMONTHDAY more than 7
return null;
}
// Check if the same BYDAY is used. Otherwise, we cannot
// support the rule
if (fields[1] != dayOfWeek) {
return null;
}
// Check if the month is same or right next to the primary month
if (fields[0] != month) {
if (anotherMonth == -1) {
int diff = fields[0] - month;
if (diff == -11 || diff == -1) {
// Previous month
anotherMonth = fields[0];
earliestMonth = anotherMonth;
// Reset earliest day
earliestDay = 31;
} else if (diff == 11 || diff == 1) {
// Next month
anotherMonth = fields[0];
} else {
// The day range cannot exceed more than 2 months
return null;
}
} else if (fields[0] != month && fields[0] != anotherMonth) {
// The day range cannot exceed more than 2 months
return null;
}
}
// If ealier month, go through days to find the earliest day
if (fields[0] == earliestMonth) {
for (int j = 0; j < count; j++) {
int dom = fields[3 + j];
dom = dom > 0 ? dom : MONTHLENGTH[fields[0]] + dom + 1;
earliestDay = dom < earliestDay ? dom : earliestDay;
}
}
daysCount += count;
}
if (daysCount != 7) {
// Number of BYMONTHDAY entries must be 7
return null;
}
month = earliestMonth;
dayOfMonth = earliestDay;
}
// Calculate start/end year and missing fields
int[] dfields = Grego.timeToFields(start + fromOffset, null);
int startYear = dfields[0];
if (month == -1) {
// If MYMONTH is not set, use the month of DTSTART
month = dfields[1];
}
if (dayOfWeek == 0 && nthDayOfWeek == 0 && dayOfMonth == 0) {
// If only YEARLY is set, use the day of DTSTART as BYMONTHDAY
dayOfMonth = dfields[2];
}
int timeInDay = dfields[5];
int endYear = AnnualTimeZoneRule.MAX_YEAR;
if (until[0] != MIN_TIME) {
Grego.timeToFields(until[0], dfields);
endYear = dfields[0];
}
// Create the AnnualDateTimeRule
DateTimeRule adtr = null;
if (dayOfWeek == 0 && nthDayOfWeek == 0 && dayOfMonth != 0) {
// Day in month rule, for example, 15th day in the month
adtr = new DateTimeRule(month, dayOfMonth, timeInDay, DateTimeRule.WALL_TIME);
} else if (dayOfWeek != 0 && nthDayOfWeek != 0 && dayOfMonth == 0) {
// Nth day of week rule, for example, last Sunday
adtr = new DateTimeRule(month, nthDayOfWeek, dayOfWeek, timeInDay, DateTimeRule.WALL_TIME);
} else if (dayOfWeek != 0 && nthDayOfWeek == 0 && dayOfMonth != 0) {
// First day of week after day of month rule, for example,
// first Sunday after 15th day in the month
adtr = new DateTimeRule(month, dayOfMonth, dayOfWeek, true, timeInDay, DateTimeRule.WALL_TIME);
} else {
// RRULE attributes are insufficient
return null;
}
return new AnnualTimeZoneRule(tzname, rawOffset, dstSavings, adtr, startYear, endYear);
}
/*
* Parse individual RRULE
*
* On return -
*
* int[0] month calculated by BYMONTH - 1, or -1 when not found
* int[1] day of week in BYDAY, or 0 when not found
* int[2] day of week ordinal number in BYDAY, or 0 when not found
* int[i >= 3] day of month, which could be multiple values, or 0 when not found
*
* or
*
* null on any error cases, for exmaple, FREQ=YEARLY is not available
*
* When UNTIL attribute is available, the time will be set to until[0],
* otherwise, MIN_TIME
*/
private static int[] parseRRULE(String rrule, long[] until) {
int month = -1;
int dayOfWeek = 0;
int nthDayOfWeek = 0;
int[] dayOfMonth = null;
long untilTime = MIN_TIME;
boolean yearly = false;
boolean parseError = false;
StringTokenizer st= new StringTokenizer(rrule, SEMICOLON);
while (st.hasMoreTokens()) {
String attr, value;
String prop = st.nextToken();
int sep = prop.indexOf(EQUALS_SIGN);
if (sep != -1) {
attr = prop.substring(0, sep);
value = prop.substring(sep + 1);
} else {
parseError = true;
break;
}
if (attr.equals(ICAL_FREQ)) {
// only support YEARLY frequency type
if (value.equals(ICAL_YEARLY)) {
yearly = true;
} else {
parseError = true;
break;
}
} else if (attr.equals(ICAL_UNTIL)) {
// ISO8601 UTC format, for example, "20060315T020000Z"
try {
untilTime = parseDateTimeString(value, 0);
} catch (IllegalArgumentException iae) {
parseError = true;
break;
}
} else if (attr.equals(ICAL_BYMONTH)) {
// Note: BYMONTH may contain multiple months, but only single month make sense for
// VTIMEZONE property.
if (value.length() > 2) {
parseError = true;
break;
}
try {
month = Integer.parseInt(value) - 1;
if (month < 0 || month >= 12) {
parseError = true;
break;
}
} catch (NumberFormatException nfe) {
parseError = true;
break;
}
} else if (attr.equals(ICAL_BYDAY)) {
// Note: BYDAY may contain multiple day of week separated by comma. It is unlikely used for
// VTIMEZONE property. We do not support the case.
// 2-letter format is used just for representing a day of week, for example, "SU" for Sunday
// 3 or 4-letter format is used for represeinging Nth day of week, for example, "-1SA" for last Saturday
int length = value.length();
if (length < 2 || length > 4) {
parseError = true;
break;
}
if (length > 2) {
// Nth day of week
int sign = 1;
if (value.charAt(0) == '+') {
sign = 1;
} else if (value.charAt(0) == '-') {
sign = -1;
} else if (length == 4) {
parseError = true;
break;
}
try {
int n = Integer.parseInt(value.substring(length - 3, length - 2));
if (n == 0 || n > 4) {
parseError = true;
break;
}
nthDayOfWeek = n * sign;
} catch(NumberFormatException nfe) {
parseError = true;
break;
}
value = value.substring(length - 2);
}
int wday;
for (wday = 0; wday < ICAL_DOW_NAMES.length; wday++) {
if (value.equals(ICAL_DOW_NAMES[wday])) {
break;
}
}
if (wday < ICAL_DOW_NAMES.length) {
// Sunday(1) - Saturday(7)
dayOfWeek = wday + 1;
} else {
parseError = true;
break;
}
} else if (attr.equals(ICAL_BYMONTHDAY)) {
// Note: BYMONTHDAY may contain multiple days delimited by comma
//
// A value of BYMONTHDAY could be negative, for example, -1 means
// the last day in a month
StringTokenizer days = new StringTokenizer(value, COMMA);
int count = days.countTokens();
dayOfMonth = new int[count];
int index = 0;
while(days.hasMoreTokens()) {
try {
dayOfMonth[index++] = Integer.parseInt(days.nextToken());
} catch (NumberFormatException nfe) {
parseError = true;
break;
}
}
}
}
if (parseError) {
return null;
}
if (!yearly) {
// FREQ=YEARLY must be set
return null;
}
until[0] = untilTime;
int[] results;
if (dayOfMonth == null) {
results = new int[4];
results[3] = 0;
} else {
results = new int[3 + dayOfMonth.length];
for (int i = 0; i < dayOfMonth.length; i++) {
results[3 + i] = dayOfMonth[i];
}
}
results[0] = month;
results[1] = dayOfWeek;
results[2] = nthDayOfWeek;
return results;
}
/*
* Create a TimeZoneRule by the RDATE definition
*/
private static TimeZoneRule createRuleByRDATE(String tzname,
int rawOffset, int dstSavings, long start, List dates, int fromOffset) {
// Create an array of transition times
long[] times;
if (dates == null || dates.size() == 0) {
// When no RDATE line is provided, use start (DTSTART)
// as the transition time
times = new long[1];
times[0] = start;
} else {
times = new long[dates.size()];
int idx = 0;
try {
for (String date : dates) {
times[idx++] = parseDateTimeString(date, fromOffset);
}
} catch (IllegalArgumentException iae) {
return null;
}
}
return new TimeArrayTimeZoneRule(tzname, rawOffset, dstSavings, times, DateTimeRule.UTC_TIME);
}
/*
* Write the time zone rules in RFC2445 VTIMEZONE format
*/
private void writeZone(Writer w, BasicTimeZone basictz, String[] customProperties) throws IOException {
// Write the header
writeHeader(w);
if (customProperties != null && customProperties.length > 0) {
for (int i = 0; i < customProperties.length; i++) {
if (customProperties[i] != null) {
w.write(customProperties[i]);
w.write(NEWLINE);
}
}
}
long t = MIN_TIME;
String dstName = null;
int dstFromOffset = 0;
int dstFromDSTSavings = 0;
int dstToOffset = 0;
int dstStartYear = 0;
int dstMonth = 0;
int dstDayOfWeek = 0;
int dstWeekInMonth = 0;
int dstMillisInDay = 0;
long dstStartTime = 0;
long dstUntilTime = 0;
int dstCount = 0;
AnnualTimeZoneRule finalDstRule = null;
String stdName = null;
int stdFromOffset = 0;
int stdFromDSTSavings = 0;
int stdToOffset = 0;
int stdStartYear = 0;
int stdMonth = 0;
int stdDayOfWeek = 0;
int stdWeekInMonth = 0;
int stdMillisInDay = 0;
long stdStartTime = 0;
long stdUntilTime = 0;
int stdCount = 0;
AnnualTimeZoneRule finalStdRule = null;
int[] dtfields = new int[6];
boolean hasTransitions = false;
// Going through all transitions
while(true) {
TimeZoneTransition tzt = basictz.getNextTransition(t, false);
if (tzt == null) {
break;
}
hasTransitions = true;
t = tzt.getTime();
String name = tzt.getTo().getName();
boolean isDst = (tzt.getTo().getDSTSavings() != 0);
int fromOffset = tzt.getFrom().getRawOffset() + tzt.getFrom().getDSTSavings();
int fromDSTSavings = tzt.getFrom().getDSTSavings();
int toOffset = tzt.getTo().getRawOffset() + tzt.getTo().getDSTSavings();
Grego.timeToFields(tzt.getTime() + fromOffset, dtfields);
int weekInMonth = Grego.getDayOfWeekInMonth(dtfields[0], dtfields[1], dtfields[2]);
int year = dtfields[0];
boolean sameRule = false;
if (isDst) {
if (finalDstRule == null && tzt.getTo() instanceof AnnualTimeZoneRule) {
if (((AnnualTimeZoneRule)tzt.getTo()).getEndYear() == AnnualTimeZoneRule.MAX_YEAR) {
finalDstRule = (AnnualTimeZoneRule)tzt.getTo();
}
}
if (dstCount > 0) {
if (year == dstStartYear + dstCount
&& name.equals(dstName)
&& dstFromOffset == fromOffset
&& dstToOffset == toOffset
&& dstMonth == dtfields[1]
&& dstDayOfWeek == dtfields[3]
&& dstWeekInMonth == weekInMonth
&& dstMillisInDay == dtfields[5]) {
// Update until time
dstUntilTime = t;
dstCount++;
sameRule = true;
}
if (!sameRule) {
if (dstCount == 1) {
writeZonePropsByTime(w, true, dstName, dstFromOffset, dstToOffset,
dstStartTime, true);
} else {
writeZonePropsByDOW(w, true, dstName, dstFromOffset, dstToOffset,
dstMonth, dstWeekInMonth, dstDayOfWeek, dstStartTime, dstUntilTime);
}
}
}
if (!sameRule) {
// Reset this DST information
dstName = name;
dstFromOffset = fromOffset;
dstFromDSTSavings = fromDSTSavings;
dstToOffset = toOffset;
dstStartYear = year;
dstMonth = dtfields[1];
dstDayOfWeek = dtfields[3];
dstWeekInMonth = weekInMonth;
dstMillisInDay = dtfields[5];
dstStartTime = dstUntilTime = t;
dstCount = 1;
}
if (finalStdRule != null && finalDstRule != null) {
break;
}
} else {
if (finalStdRule == null && tzt.getTo() instanceof AnnualTimeZoneRule) {
if (((AnnualTimeZoneRule)tzt.getTo()).getEndYear() == AnnualTimeZoneRule.MAX_YEAR) {
finalStdRule = (AnnualTimeZoneRule)tzt.getTo();
}
}
if (stdCount > 0) {
if (year == stdStartYear + stdCount
&& name.equals(stdName)
&& stdFromOffset == fromOffset
&& stdToOffset == toOffset
&& stdMonth == dtfields[1]
&& stdDayOfWeek == dtfields[3]
&& stdWeekInMonth == weekInMonth
&& stdMillisInDay == dtfields[5]) {
// Update until time
stdUntilTime = t;
stdCount++;
sameRule = true;
}
if (!sameRule) {
if (stdCount == 1) {
writeZonePropsByTime(w, false, stdName, stdFromOffset, stdToOffset,
stdStartTime, true);
} else {
writeZonePropsByDOW(w, false, stdName, stdFromOffset, stdToOffset,
stdMonth, stdWeekInMonth, stdDayOfWeek, stdStartTime, stdUntilTime);
}
}
}
if (!sameRule) {
// Reset this STD information
stdName = name;
stdFromOffset = fromOffset;
stdFromDSTSavings = fromDSTSavings;
stdToOffset = toOffset;
stdStartYear = year;
stdMonth = dtfields[1];
stdDayOfWeek = dtfields[3];
stdWeekInMonth = weekInMonth;
stdMillisInDay = dtfields[5];
stdStartTime = stdUntilTime = t;
stdCount = 1;
}
if (finalStdRule != null && finalDstRule != null) {
break;
}
}
}
if (!hasTransitions) {
// No transition - put a single non transition RDATE
int offset = basictz.getOffset(0 /* any time */);
boolean isDst = (offset != basictz.getRawOffset());
writeZonePropsByTime(w, isDst, getDefaultTZName(basictz.getID(), isDst),
offset, offset, DEF_TZSTARTTIME - offset, false);
} else {
if (dstCount > 0) {
if (finalDstRule == null) {
if (dstCount == 1) {
writeZonePropsByTime(w, true, dstName, dstFromOffset, dstToOffset,
dstStartTime, true);
} else {
writeZonePropsByDOW(w, true, dstName, dstFromOffset, dstToOffset,
dstMonth, dstWeekInMonth, dstDayOfWeek, dstStartTime, dstUntilTime);
}
} else {
if (dstCount == 1) {
writeFinalRule(w, true, finalDstRule,
dstFromOffset - dstFromDSTSavings, dstFromDSTSavings, dstStartTime);
} else {
// Use a single rule if possible
if (isEquivalentDateRule(dstMonth, dstWeekInMonth, dstDayOfWeek, finalDstRule.getRule())) {
writeZonePropsByDOW(w, true, dstName, dstFromOffset, dstToOffset,
dstMonth, dstWeekInMonth, dstDayOfWeek, dstStartTime, MAX_TIME);
} else {
// Not equivalent rule - write out two different rules
writeZonePropsByDOW(w, true, dstName, dstFromOffset, dstToOffset,
dstMonth, dstWeekInMonth, dstDayOfWeek, dstStartTime, dstUntilTime);
Date nextStart = finalDstRule.getNextStart(dstUntilTime,
dstFromOffset - dstFromDSTSavings, dstFromDSTSavings, false);
assert nextStart != null;
if (nextStart != null) {
writeFinalRule(w, true, finalDstRule,
dstFromOffset - dstFromDSTSavings, dstFromDSTSavings, nextStart.getTime());
}
}
}
}
}
if (stdCount > 0) {
if (finalStdRule == null) {
if (stdCount == 1) {
writeZonePropsByTime(w, false, stdName, stdFromOffset, stdToOffset,
stdStartTime, true);
} else {
writeZonePropsByDOW(w, false, stdName, stdFromOffset, stdToOffset,
stdMonth, stdWeekInMonth, stdDayOfWeek, stdStartTime, stdUntilTime);
}
} else {
if (stdCount == 1) {
writeFinalRule(w, false, finalStdRule,
stdFromOffset - stdFromDSTSavings, stdFromDSTSavings, stdStartTime);
} else {
// Use a single rule if possible
if (isEquivalentDateRule(stdMonth, stdWeekInMonth, stdDayOfWeek, finalStdRule.getRule())) {
writeZonePropsByDOW(w, false, stdName, stdFromOffset, stdToOffset,
stdMonth, stdWeekInMonth, stdDayOfWeek, stdStartTime, MAX_TIME);
} else {
// Not equivalent rule - write out two different rules
writeZonePropsByDOW(w, false, stdName, stdFromOffset, stdToOffset,
stdMonth, stdWeekInMonth, stdDayOfWeek, stdStartTime, stdUntilTime);
Date nextStart = finalStdRule.getNextStart(stdUntilTime,
stdFromOffset - stdFromDSTSavings, stdFromDSTSavings, false);
assert nextStart != null;
if (nextStart != null) {
writeFinalRule(w, false, finalStdRule,
stdFromOffset - stdFromDSTSavings, stdFromDSTSavings, nextStart.getTime());
}
}
}
}
}
}
writeFooter(w);
}
/*
* Check if the DOW rule specified by month, weekInMonth and dayOfWeek is equivalent
* to the DateTimerule.
*/
private static boolean isEquivalentDateRule(int month, int weekInMonth, int dayOfWeek, DateTimeRule dtrule) {
if (month != dtrule.getRuleMonth() || dayOfWeek != dtrule.getRuleDayOfWeek()) {
return false;
}
if (dtrule.getTimeRuleType() != DateTimeRule.WALL_TIME) {
// Do not try to do more intelligent comparison for now.
return false;
}
if (dtrule.getDateRuleType() == DateTimeRule.DOW
&& dtrule.getRuleWeekInMonth() == weekInMonth) {
return true;
}
int ruleDOM = dtrule.getRuleDayOfMonth();
if (dtrule.getDateRuleType() == DateTimeRule.DOW_GEQ_DOM) {
if (ruleDOM%7 == 1 && (ruleDOM + 6)/7 == weekInMonth) {
return true;
}
if (month != Calendar.FEBRUARY && (MONTHLENGTH[month] - ruleDOM)%7 == 6
&& weekInMonth == -1*((MONTHLENGTH[month]-ruleDOM+1)/7)) {
return true;
}
}
if (dtrule.getDateRuleType() == DateTimeRule.DOW_LEQ_DOM) {
if (ruleDOM%7 == 0 && ruleDOM/7 == weekInMonth) {
return true;
}
if (month != Calendar.FEBRUARY && (MONTHLENGTH[month] - ruleDOM)%7 == 0
&& weekInMonth == -1*((MONTHLENGTH[month] - ruleDOM)/7 + 1)) {
return true;
}
}
return false;
}
/*
* Write a single start time
*/
private static void writeZonePropsByTime(Writer writer, boolean isDst, String tzname,
int fromOffset, int toOffset, long time, boolean withRDATE) throws IOException {
beginZoneProps(writer, isDst, tzname, fromOffset, toOffset, time);
if (withRDATE) {
writer.write(ICAL_RDATE);
writer.write(COLON);
writer.write(getDateTimeString(time + fromOffset));
writer.write(NEWLINE);
}
endZoneProps(writer, isDst);
}
/*
* Write start times defined by a DOM rule using VTIMEZONE RRULE
*/
private static void writeZonePropsByDOM(Writer writer, boolean isDst, String tzname, int fromOffset, int toOffset,
int month, int dayOfMonth, long startTime, long untilTime) throws IOException {
beginZoneProps(writer, isDst, tzname, fromOffset, toOffset, startTime);
beginRRULE(writer, month);
writer.write(ICAL_BYMONTHDAY);
writer.write(EQUALS_SIGN);
writer.write(Integer.toString(dayOfMonth));
if (untilTime != MAX_TIME) {
appendUNTIL(writer, getDateTimeString(untilTime + fromOffset));
}
writer.write(NEWLINE);
endZoneProps(writer, isDst);
}
/*
* Write start times defined by a DOW rule using VTIMEZONE RRULE
*/
private static void writeZonePropsByDOW(Writer writer, boolean isDst, String tzname, int fromOffset, int toOffset,
int month, int weekInMonth, int dayOfWeek, long startTime, long untilTime) throws IOException {
beginZoneProps(writer, isDst, tzname, fromOffset, toOffset, startTime);
beginRRULE(writer, month);
writer.write(ICAL_BYDAY);
writer.write(EQUALS_SIGN);
writer.write(Integer.toString(weekInMonth)); // -4, -3, -2, -1, 1, 2, 3, 4
writer.write(ICAL_DOW_NAMES[dayOfWeek - 1]); // SU, MO, TU...
if (untilTime != MAX_TIME) {
appendUNTIL(writer, getDateTimeString(untilTime + fromOffset));
}
writer.write(NEWLINE);
endZoneProps(writer, isDst);
}
/*
* Write start times defined by a DOW_GEQ_DOM rule using VTIMEZONE RRULE
*/
private static void writeZonePropsByDOW_GEQ_DOM(Writer writer, boolean isDst, String tzname, int fromOffset, int toOffset,
int month, int dayOfMonth, int dayOfWeek, long startTime, long untilTime) throws IOException {
// Check if this rule can be converted to DOW rule
if (dayOfMonth%7 == 1) {
// Can be represented by DOW rule
writeZonePropsByDOW(writer, isDst, tzname, fromOffset, toOffset,
month, (dayOfMonth + 6)/7, dayOfWeek, startTime, untilTime);
} else if (month != Calendar.FEBRUARY && (MONTHLENGTH[month] - dayOfMonth)%7 == 6) {
// Can be represented by DOW rule with negative week number
writeZonePropsByDOW(writer, isDst, tzname, fromOffset, toOffset,
month, -1*((MONTHLENGTH[month] - dayOfMonth + 1)/7), dayOfWeek, startTime, untilTime);
} else {
// Otherwise, use BYMONTHDAY to include all possible dates
beginZoneProps(writer, isDst, tzname, fromOffset, toOffset, startTime);
// Check if all days are in the same month
int startDay = dayOfMonth;
int currentMonthDays = 7;
if (dayOfMonth <= 0) {
// The start day is in previous month
int prevMonthDays = 1 - dayOfMonth;
currentMonthDays -= prevMonthDays;
int prevMonth = (month - 1) < 0 ? 11 : month - 1;
// Note: When a rule is separated into two, UNTIL attribute needs to be
// calculated for each of them. For now, we skip this, because we basically use this method
// only for final rules, which does not have the UNTIL attribute
writeZonePropsByDOW_GEQ_DOM_sub(writer, prevMonth, -prevMonthDays, dayOfWeek, prevMonthDays, MAX_TIME /* Do not use UNTIL */, fromOffset);
// Start from 1 for the rest
startDay = 1;
} else if (dayOfMonth + 6 > MONTHLENGTH[month]) {
// Note: This code does not actually work well in February. For now, days in month in
// non-leap year.
int nextMonthDays = dayOfMonth + 6 - MONTHLENGTH[month];
currentMonthDays -= nextMonthDays;
int nextMonth = (month + 1) > 11 ? 0 : month + 1;
writeZonePropsByDOW_GEQ_DOM_sub(writer, nextMonth, 1, dayOfWeek, nextMonthDays, MAX_TIME /* Do not use UNTIL */, fromOffset);
}
writeZonePropsByDOW_GEQ_DOM_sub(writer, month, startDay, dayOfWeek, currentMonthDays, untilTime, fromOffset);
endZoneProps(writer, isDst);
}
}
/*
* Called from writeZonePropsByDOW_GEQ_DOM
*/
private static void writeZonePropsByDOW_GEQ_DOM_sub(Writer writer, int month,
int dayOfMonth, int dayOfWeek, int numDays, long untilTime, int fromOffset) throws IOException {
int startDayNum = dayOfMonth;
boolean isFeb = (month == Calendar.FEBRUARY);
if (dayOfMonth < 0 && !isFeb) {
// Use positive number if possible
startDayNum = MONTHLENGTH[month] + dayOfMonth + 1;
}
beginRRULE(writer, month);
writer.write(ICAL_BYDAY);
writer.write(EQUALS_SIGN);
writer.write(ICAL_DOW_NAMES[dayOfWeek - 1]); // SU, MO, TU...
writer.write(SEMICOLON);
writer.write(ICAL_BYMONTHDAY);
writer.write(EQUALS_SIGN);
writer.write(Integer.toString(startDayNum));
for (int i = 1; i < numDays; i++) {
writer.write(COMMA);
writer.write(Integer.toString(startDayNum + i));
}
if (untilTime != MAX_TIME) {
appendUNTIL(writer, getDateTimeString(untilTime + fromOffset));
}
writer.write(NEWLINE);
}
/*
* Write start times defined by a DOW_LEQ_DOM rule using VTIMEZONE RRULE
*/
private static void writeZonePropsByDOW_LEQ_DOM(Writer writer, boolean isDst, String tzname, int fromOffset, int toOffset,
int month, int dayOfMonth, int dayOfWeek, long startTime, long untilTime) throws IOException {
// Check if this rule can be converted to DOW rule
if (dayOfMonth%7 == 0) {
// Can be represented by DOW rule
writeZonePropsByDOW(writer, isDst, tzname, fromOffset, toOffset,
month, dayOfMonth/7, dayOfWeek, startTime, untilTime);
} else if (month != Calendar.FEBRUARY && (MONTHLENGTH[month] - dayOfMonth)%7 == 0){
// Can be represented by DOW rule with negative week number
writeZonePropsByDOW(writer, isDst, tzname, fromOffset, toOffset,
month, -1*((MONTHLENGTH[month] - dayOfMonth)/7 + 1), dayOfWeek, startTime, untilTime);
} else if (month == Calendar.FEBRUARY && dayOfMonth == 29) {
// Specical case for February
writeZonePropsByDOW(writer, isDst, tzname, fromOffset, toOffset,
Calendar.FEBRUARY, -1, dayOfWeek, startTime, untilTime);
} else {
// Otherwise, convert this to DOW_GEQ_DOM rule
writeZonePropsByDOW_GEQ_DOM(writer, isDst, tzname, fromOffset, toOffset,
month, dayOfMonth - 6, dayOfWeek, startTime, untilTime);
}
}
/*
* Write the final time zone rule using RRULE, with no UNTIL attribute
*/
private static void writeFinalRule(Writer writer, boolean isDst, AnnualTimeZoneRule rule,
int fromRawOffset, int fromDSTSavings, long startTime) throws IOException{
DateTimeRule dtrule = toWallTimeRule(rule.getRule(), fromRawOffset, fromDSTSavings);
// If the rule's mills in a day is out of range, adjust start time.
// Olson tzdata supports 24:00 of a day, but VTIMEZONE does not.
// See ticket#7008/#7518
int timeInDay = dtrule.getRuleMillisInDay();
if (timeInDay < 0) {
startTime = startTime + (0 - timeInDay);
} else if (timeInDay >= Grego.MILLIS_PER_DAY) {
startTime = startTime - (timeInDay - (Grego.MILLIS_PER_DAY - 1));
}
int toOffset = rule.getRawOffset() + rule.getDSTSavings();
switch (dtrule.getDateRuleType()) {
case DateTimeRule.DOM:
writeZonePropsByDOM(writer, isDst, rule.getName(), fromRawOffset + fromDSTSavings, toOffset,
dtrule.getRuleMonth(), dtrule.getRuleDayOfMonth(), startTime, MAX_TIME);
break;
case DateTimeRule.DOW:
writeZonePropsByDOW(writer, isDst, rule.getName(), fromRawOffset + fromDSTSavings, toOffset,
dtrule.getRuleMonth(), dtrule.getRuleWeekInMonth(), dtrule.getRuleDayOfWeek(), startTime, MAX_TIME);
break;
case DateTimeRule.DOW_GEQ_DOM:
writeZonePropsByDOW_GEQ_DOM(writer, isDst, rule.getName(), fromRawOffset + fromDSTSavings, toOffset,
dtrule.getRuleMonth(), dtrule.getRuleDayOfMonth(), dtrule.getRuleDayOfWeek(), startTime, MAX_TIME);
break;
case DateTimeRule.DOW_LEQ_DOM:
writeZonePropsByDOW_LEQ_DOM(writer, isDst, rule.getName(), fromRawOffset + fromDSTSavings, toOffset,
dtrule.getRuleMonth(), dtrule.getRuleDayOfMonth(), dtrule.getRuleDayOfWeek(), startTime, MAX_TIME);
break;
}
}
/*
* Convert the rule to its equivalent rule using WALL_TIME mode
*/
private static DateTimeRule toWallTimeRule(DateTimeRule rule, int rawOffset, int dstSavings) {
if (rule.getTimeRuleType() == DateTimeRule.WALL_TIME) {
return rule;
}
int wallt = rule.getRuleMillisInDay();
if (rule.getTimeRuleType() == DateTimeRule.UTC_TIME) {
wallt += (rawOffset + dstSavings);
} else if (rule.getTimeRuleType() == DateTimeRule.STANDARD_TIME) {
wallt += dstSavings;
}
int month = -1, dom = 0, dow = 0, dtype = -1;
int dshift = 0;
if (wallt < 0) {
dshift = -1;
wallt += Grego.MILLIS_PER_DAY;
} else if (wallt >= Grego.MILLIS_PER_DAY) {
dshift = 1;
wallt -= Grego.MILLIS_PER_DAY;
}
month = rule.getRuleMonth();
dom = rule.getRuleDayOfMonth();
dow = rule.getRuleDayOfWeek();
dtype = rule.getDateRuleType();
if (dshift != 0) {
if (dtype == DateTimeRule.DOW) {
// Convert to DOW_GEW_DOM or DOW_LEQ_DOM rule first
int wim = rule.getRuleWeekInMonth();
if (wim > 0) {
dtype = DateTimeRule.DOW_GEQ_DOM;
dom = 7 * (wim - 1) + 1;
} else {
dtype = DateTimeRule.DOW_LEQ_DOM;
dom = MONTHLENGTH[month] + 7 * (wim + 1);
}
}
// Shift one day before or after
dom += dshift;
if (dom == 0) {
month--;
month = month < Calendar.JANUARY ? Calendar.DECEMBER : month;
dom = MONTHLENGTH[month];
} else if (dom > MONTHLENGTH[month]) {
month++;
month = month > Calendar.DECEMBER ? Calendar.JANUARY : month;
dom = 1;
}
if (dtype != DateTimeRule.DOM) {
// Adjust day of week
dow += dshift;
if (dow < Calendar.SUNDAY) {
dow = Calendar.SATURDAY;
} else if (dow > Calendar.SATURDAY) {
dow = Calendar.SUNDAY;
}
}
}
// Create a new rule
DateTimeRule modifiedRule;
if (dtype == DateTimeRule.DOM) {
modifiedRule = new DateTimeRule(month, dom, wallt, DateTimeRule.WALL_TIME);
} else {
modifiedRule = new DateTimeRule(month, dom, dow,
(dtype == DateTimeRule.DOW_GEQ_DOM), wallt, DateTimeRule.WALL_TIME);
}
return modifiedRule;
}
/*
* Write the opening section of zone properties
*/
private static void beginZoneProps(Writer writer, boolean isDst, String tzname, int fromOffset, int toOffset, long startTime) throws IOException {
writer.write(ICAL_BEGIN);
writer.write(COLON);
if (isDst) {
writer.write(ICAL_DAYLIGHT);
} else {
writer.write(ICAL_STANDARD);
}
writer.write(NEWLINE);
// TZOFFSETTO
writer.write(ICAL_TZOFFSETTO);
writer.write(COLON);
writer.write(millisToOffset(toOffset));
writer.write(NEWLINE);
// TZOFFSETFROM
writer.write(ICAL_TZOFFSETFROM);
writer.write(COLON);
writer.write(millisToOffset(fromOffset));
writer.write(NEWLINE);
// TZNAME
writer.write(ICAL_TZNAME);
writer.write(COLON);
writer.write(tzname);
writer.write(NEWLINE);
// DTSTART
writer.write(ICAL_DTSTART);
writer.write(COLON);
writer.write(getDateTimeString(startTime + fromOffset));
writer.write(NEWLINE);
}
/*
* Writes the closing section of zone properties
*/
private static void endZoneProps(Writer writer, boolean isDst) throws IOException{
// END:STANDARD or END:DAYLIGHT
writer.write(ICAL_END);
writer.write(COLON);
if (isDst) {
writer.write(ICAL_DAYLIGHT);
} else {
writer.write(ICAL_STANDARD);
}
writer.write(NEWLINE);
}
/*
* Write the beginning part of RRULE line
*/
private static void beginRRULE(Writer writer, int month) throws IOException {
writer.write(ICAL_RRULE);
writer.write(COLON);
writer.write(ICAL_FREQ);
writer.write(EQUALS_SIGN);
writer.write(ICAL_YEARLY);
writer.write(SEMICOLON);
writer.write(ICAL_BYMONTH);
writer.write(EQUALS_SIGN);
writer.write(Integer.toString(month + 1));
writer.write(SEMICOLON);
}
/*
* Append the UNTIL attribute after RRULE line
*/
private static void appendUNTIL(Writer writer, String until) throws IOException {
if (until != null) {
writer.write(SEMICOLON);
writer.write(ICAL_UNTIL);
writer.write(EQUALS_SIGN);
writer.write(until);
}
}
/*
* Write the opening section of the VTIMEZONE block
*/
private void writeHeader(Writer writer)throws IOException {
writer.write(ICAL_BEGIN);
writer.write(COLON);
writer.write(ICAL_VTIMEZONE);
writer.write(NEWLINE);
writer.write(ICAL_TZID);
writer.write(COLON);
writer.write(tz.getID());
writer.write(NEWLINE);
if (tzurl != null) {
writer.write(ICAL_TZURL);
writer.write(COLON);
writer.write(tzurl);
writer.write(NEWLINE);
}
if (lastmod != null) {
writer.write(ICAL_LASTMOD);
writer.write(COLON);
writer.write(getUTCDateTimeString(lastmod.getTime()));
writer.write(NEWLINE);
}
}
/*
* Write the closing section of the VTIMEZONE definition block
*/
private static void writeFooter(Writer writer) throws IOException {
writer.write(ICAL_END);
writer.write(COLON);
writer.write(ICAL_VTIMEZONE);
writer.write(NEWLINE);
}
/*
* Convert date/time to RFC2445 Date-Time form #1 DATE WITH LOCAL TIME
*/
private static String getDateTimeString(long time) {
int[] fields = Grego.timeToFields(time, null);
StringBuilder sb = new StringBuilder(15);
sb.append(numToString(fields[0], 4));
sb.append(numToString(fields[1] + 1, 2));
sb.append(numToString(fields[2], 2));
sb.append('T');
int t = fields[5];
int hour = t / Grego.MILLIS_PER_HOUR;
t %= Grego.MILLIS_PER_HOUR;
int min = t / Grego.MILLIS_PER_MINUTE;
t %= Grego.MILLIS_PER_MINUTE;
int sec = t / Grego.MILLIS_PER_SECOND;
sb.append(numToString(hour, 2));
sb.append(numToString(min, 2));
sb.append(numToString(sec, 2));
return sb.toString();
}
/*
* Convert date/time to RFC2445 Date-Time form #2 DATE WITH UTC TIME
*/
private static String getUTCDateTimeString(long time) {
return getDateTimeString(time) + "Z";
}
/*
* Parse RFC2445 Date-Time form #1 DATE WITH LOCAL TIME and
* #2 DATE WITH UTC TIME
*/
private static long parseDateTimeString(String str, int offset) {
int year = 0, month = 0, day = 0, hour = 0, min = 0, sec = 0;
boolean isUTC = false;
boolean isValid = false;
do {
if (str == null) {
break;
}
int length = str.length();
if (length != 15 && length != 16) {
// FORM#1 15 characters, such as "20060317T142115"
// FORM#2 16 characters, such as "20060317T142115Z"
break;
}
if (str.charAt(8) != 'T') {
// charcter "T" must be used for separating date and time
break;
}
if (length == 16) {
if (str.charAt(15) != 'Z') {
// invalid format
break;
}
isUTC = true;
}
try {
year = Integer.parseInt(str.substring(0, 4));
month = Integer.parseInt(str.substring(4, 6)) - 1; // 0-based
day = Integer.parseInt(str.substring(6, 8));
hour = Integer.parseInt(str.substring(9, 11));
min = Integer.parseInt(str.substring(11, 13));
sec = Integer.parseInt(str.substring(13, 15));
} catch (NumberFormatException nfe) {
break;
}
// check valid range
int maxDayOfMonth = Grego.monthLength(year, month);
if (year < 0 || month < 0 || month > 11 || day < 1 || day > maxDayOfMonth ||
hour < 0 || hour >= 24 || min < 0 || min >= 60 || sec < 0 || sec >= 60) {
break;
}
isValid = true;
} while(false);
if (!isValid) {
throw new IllegalArgumentException("Invalid date time string format");
}
// Calculate the time
long time = Grego.fieldsToDay(year, month, day) * Grego.MILLIS_PER_DAY;
time += (hour*Grego.MILLIS_PER_HOUR + min*Grego.MILLIS_PER_MINUTE + sec*Grego.MILLIS_PER_SECOND);
if (!isUTC) {
time -= offset;
}
return time;
}
/*
* Convert RFC2445 utc-offset string to milliseconds
*/
private static int offsetStrToMillis(String str) {
boolean isValid = false;
int sign = 0, hour = 0, min = 0, sec = 0;
do {
if (str == null) {
break;
}
int length = str.length();
if (length != 5 && length != 7) {
// utf-offset must be 5 or 7 characters
break;
}
// sign
char s = str.charAt(0);
if (s == '+') {
sign = 1;
} else if (s == '-') {
sign = -1;
} else {
// utf-offset must start with "+" or "-"
break;
}
try {
hour = Integer.parseInt(str.substring(1, 3));
min = Integer.parseInt(str.substring(3, 5));
if (length == 7) {
sec = Integer.parseInt(str.substring(5, 7));
}
} catch (NumberFormatException nfe) {
break;
}
isValid = true;
} while(false);
if (!isValid) {
throw new IllegalArgumentException("Bad offset string");
}
int millis = sign * ((hour * 60 + min) * 60 + sec) * 1000;
return millis;
}
/*
* Convert milliseconds to RFC2445 utc-offset string
*/
private static String millisToOffset(int millis) {
StringBuilder sb = new StringBuilder(7);
if (millis >= 0) {
sb.append('+');
} else {
sb.append('-');
millis = -millis;
}
int hour, min, sec;
int t = millis / 1000;
sec = t % 60;
t = (t - sec) / 60;
min = t % 60;
hour = t / 60;
sb.append(numToString(hour, 2));
sb.append(numToString(min, 2));
sb.append(numToString(sec, 2));
return sb.toString();
}
/*
* Format integer number
*/
private static String numToString(int num, int width) {
String str = Integer.toString(num);
int len = str.length();
if (len >= width) {
return str.substring(len - width, len);
}
StringBuilder sb = new StringBuilder(width);
for (int i = len; i < width; i++) {
sb.append('0');
}
sb.append(str);
return sb.toString();
}
// Freezable stuffs
private volatile transient boolean isFrozen = false;
/**
* {@inheritDoc}
* @stable ICU 49
*/
public boolean isFrozen() {
return isFrozen;
}
/**
* {@inheritDoc}
* @stable ICU 49
*/
public TimeZone freeze() {
isFrozen = true;
return this;
}
/**
* {@inheritDoc}
* @stable ICU 49
*/
public TimeZone cloneAsThawed() {
VTimeZone vtz = (VTimeZone)super.cloneAsThawed();
vtz.tz = (BasicTimeZone)tz.cloneAsThawed();
vtz.isFrozen = false;
return vtz;
}
}