/*
* @(#)DateParser.java 1.8 02/10/10 @(#)
*
* Copyright (c) 1999-2002 Sun Microsystems, Inc. All rights reserved.
* PROPRIETARY/CONFIDENTIAL
* Use is subject to license terms.
*/
package com.sun.midp.io;
import java.util.Hashtable;
/**
* This class implements somewhat of a subset of the J2SE Date class.
* However, since the semantics of parse() is slightly different
* (DateParser will not handle dates prior to 1/1/1970, amd to
* be able to provide methods that will set timezone and DST
* information, it is called DateParser.
*/
public class DateParser {
/** The year represented by this date */
protected int year;
/** The month represented by this date */
protected int month;
/** The day of the month represented by this date */
protected int day;
/** The hour represented by this date */
protected int hour;
/** The minute represented by this date */
protected int minute;
/** The second represented by this date */
protected int second;
/** The millisecond represented by this date */
protected int milli;
/** The offset, in milliseconds, from GMT represented by this date */
protected int tzoffset;
/** The offset, in milliseconds, from GMT for the local time zone */
protected static int local_tz;
/**
* Allocates a <code>DateParser</code> object and initializes it so that
* it represents the instant at the start of the second specified
* by the <code>year</code>, <code>month</code>, <code>date</code>,
* <code>hrs</code>, <code>min</code>, and <code>sec</code> arguments,
* in the local time zone.
*
* @param year the year, >= 1583.
* @param month the month between 0-11.
* @param day the day of the month between 1-31.
* @param hour the hours between 0-23.
* @param minute the minutes between 0-59.
* @param second the seconds between 0-59.
*/
DateParser(int year, int month, int day,
int hour, int minute, int second) {
if (year < 1583
|| month < 0 || month > 11
|| day < 0 || (day > days_in_month[month]
&& !(month == 1 && day == 29 && year % 4 == 0))
|| hour < 0 || hour > 23
|| minute < 0 || minute > 59
|| second < 0 || second > 59) {
throw new IllegalArgumentException();
}
this.year = year;
this.month = month;
this.day = day;
this.hour = hour;
this.minute = minute;
this.second = second;
milli = 0;
}
/**
* Allocates a <code>DateParser</code> object and initializes it so that
* it represents the date and time indicated by the string
* <code>s</code>, which is interpreted as if by the
* {@link DateParser#parse} method.
*
* @param s a string representation of the date.
*/
DateParser(String s) {
internalParse(s);
}
/**
* Set the local time zone for the DateParser class.
* <code>tz</code> must in abbreviated format, e.g. "PST"
* for Pacific Standard Time.
*
* @param tz The time zone string in abbreviated format.
*/
static void setTimeZone(String tz) {
if (timezones.get(tz) == null) {
return;
}
local_tz = ((Integer)timezones.get(tz)).intValue();
}
/**
* Attempts to interpret the string <tt>s</tt> as a representation
* of a date and time. If the attempt is successful, the time
* indicated is returned represented as teh distance, measured in
* milliseconds, of that time from the epoch (00:00:00 GMT on
* January 1, 1970). If the attempt fails, an
* <tt>IllegalArgumentException</tt> is thrown.
* <p>
* It accepts many syntaxes; in particular, it recognizes the IETF
* standard date syntax: "Sat, 12 Aug 1995 13:30:00 GMT". It also
* understands the continental U.S. time-zone abbreviations, but for
* general use, a time-zone offset should be used: "Sat, 12 Aug 1995
* 13:30:00 GMT+0430" (4 hours, 30 minutes west of the Greenwich
* meridian). If no time zone is specified, the local time zone is
* assumed. GMT and UTC are considered equivalent.
* <p>
* The string <tt>s</tt> is processed from left to right, looking for
* data of interest. Any material in <tt>s</tt> that is within the
* ASCII parenthesis characters <tt>(</tt> and <tt>)</tt> is ignored.
* Parentheses may be nested. Otherwise, the only characters permitted
* within <tt>s</tt> are these ASCII characters:
* <blockquote><pre>
* abcdefghijklmnopqrstuvwxyz
* ABCDEFGHIJKLMNOPQRSTUVWXYZ
* 0123456789,+-:/</pre></blockquote>
* and whitespace characters.<p>
* A consecutive sequence of decimal digits is treated as a decimal
* number:<ul>
* <li>If a number is preceded by <tt>+</tt> or <tt>-</tt> and a year
* has already been recognized, then the number is a time-zone
* offset. If the number is less than 24, it is an offset measured
* in hours. Otherwise, it is regarded as an offset in minutes,
* expressed in 24-hour time format without punctuation. A
* preceding <tt>-</tt> means a westward offset. Time zone offsets
* are always relative to UTC (Greenwich). Thus, for example,
* <tt>-5</tt> occurring in the string would mean "five hours west
* of Greenwich" and <tt>+0430</tt> would mean "four hours and
* thirty minutes east of Greenwich." It is permitted for the
* string to specify <tt>GMT</tt>, <tt>UT</tt>, or <tt>UTC</tt>
* redundantly-for example, <tt>GMT-5</tt> or <tt>utc+0430</tt>.
* <li>If a number is greater than 70, it is regarded as a year number.
* It must be followed by a space, comma, slash, or end of string.
* <li>If the number is followed by a colon, it is regarded as an hour,
* unless an hour has already been recognized, in which case it is
* regarded as a minute.
* <li>If the number is followed by a slash, it is regarded as a month
* (it is decreased by 1 to produce a number in the range <tt>0</tt>
* to <tt>11</tt>), unless a month has already been recognized, in
* which case it is regarded as a day of the month.
* <li>If the number is followed by whitespace, a comma, a hyphen, or
* end of string, then if an hour has been recognized but not a
* minute, it is regarded as a minute; otherwise, if a minute has
* been recognized but not a second, it is regarded as a second;
* otherwise, it is regarded as a day of the month. </ul><p>
* A consecutive sequence of letters is regarded as a word and treated
* as follows:<ul>
* <li>A word that matches <tt>AM</tt>, ignoring case, is ignored (but
* the parse fails if an hour has not been recognized or is less
* than <tt>1</tt> or greater than <tt>12</tt>).
* <li>A word that matches <tt>PM</tt>, ignoring case, adds <tt>12</tt>
* to the hour (but the parse fails if an hour has not been
* recognized or is less than <tt>1</tt> or greater than <tt>12</tt>).
* <li>Any word that matches any prefix of <tt>SUNDAY, MONDAY, TUESDAY,
* WEDNESDAY, THURSDAY, FRIDAY</tt>, or <tt>SATURDAY</tt>, ignoring
* case, is ignored. For example, <tt>sat, Friday, TUE</tt>, and
* <tt>Thurs</tt> are ignored.
* <li>Otherwise, any word that matches any prefix of <tt>JANUARY,
* FEBRUARY, MARCH, APRIL, MAY, JUNE, JULY, AUGUST, SEPTEMBER,
* OCTOBER, NOVEMBER</tt>, or <tt>DECEMBER</tt>, ignoring case, and
* considering them in the order given here, is recognized as
* specifying a month and is converted to a number (<tt>0</tt> to
* <tt>11</tt>). For example, <tt>aug, Sept, april</tt>, and
* <tt>NOV</tt> are recognized as months. So is <tt>Ma</tt>, which
* is recognized as <tt>MARCH</tt>, not <tt>MAY</tt>.
* <li>Any word that matches <tt>GMT, UT</tt>, or <tt>UTC</tt>, ignoring
* case, is treated as referring to UTC.
* <li>Any word that matches <tt>EST, CST, MST</tt>, or <tt>PST</tt>,
* ignoring case, is recognized as referring to the time zone in
* North America that is five, six, seven, or eight hours west of
* Greenwich, respectively. Any word that matches <tt>EDT, CDT,
* MDT</tt>, or <tt>PDT</tt>, ignoring case, is recognized as
* referring to the same time zone, respectively, during daylight
* saving time.</ul><p>
* Once the entire string s has been scanned, it is converted to a time
* result in one of two ways. If a time zone or time-zone offset has been
* recognized, then the year, month, day of month, hour, minute, and
* second are interpreted in UTC and then the time-zone offset is
* applied. Otherwise, the year, month, day of month, hour, minute, and
* second are interpreted in the local time zone.
*
* @param s a string to be parsed as a date.
* @return the distance in milliseconds from January 1, 1970, 00:00:00 GMT
* represented by the string argument. Note that this method will
* throw an <code>IllegalArgumentException</code> if the year
* indicated in <code>s</code> is less than 1583.
*/
public static long parse(String s) {
return (new DateParser(s)).getTime();
}
/**
* Get the year represented by this date.
*
* @return The year.
*/
int getYear() {
return year;
}
/**
* Get the month represented by this date.
*
* @return The month.
*/
int getMonth() {
return month;
}
/**
* Get the day of the month represented by this date.
*
* @return The day of the month.
*/
int getDay() {
return day;
}
/**
* Get the hour represented by this date.
*
* @return The hour.
*/
int getHour() {
return hour;
}
/**
* Get the minute represented by this date.
*
* @return The minute.
*/
int getMinute() {
return minute;
}
/**
* Get the second represented by this date.
*
* @return The second.
*/
int getSecond() {
return second;
}
/**
* Calculate the number of milliseconds since 01/01/1970 represented
* by this date.
*
* @return the number of milliseconds.
*/
long getTime() {
long julianDay = computeJulianDay(year, month, day);
long millis = julianDayToMillis(julianDay);
int millisInDay = 0;
millisInDay += hour;
millisInDay *= 60;
millisInDay += minute; // now have minutes
millisInDay *= 60;
millisInDay += second; // now have seconds
millisInDay *= 1000;
millisInDay += milli; // now have millis
return millis + millisInDay - tzoffset;
}
/**
* Calculate the number of Julian days since Jan 1, year 1 as
* represented by the <code>year</code>, <code>month</code>,
* and <code>day</code>.
*
* @param year The Gegorian year
* @param month The month
* @param day The day of the month <code>month</code>
* @return the number of Julian days.
*/
private final long computeJulianDay(int year, int month, int day) {
int y;
long millis = 0;
boolean isLeap = year%4 == 0;
y = year - 1;
long julianDay = 365L*y + floorDivide(y, 4) + (JAN_1_1_JULIAN_DAY - 3);
isLeap = isLeap && ((year%100 != 0) || (year%400 == 0));
// Add 2 because Gregorian calendar starts 2 days after Julian calendar
julianDay += floorDivide(y, 400) - floorDivide(y, 100) + 2;
julianDay += isLeap ? LEAP_NUM_DAYS[month] : NUM_DAYS[month];
julianDay += day;
return julianDay;
}
/**
* Divide two long integers, returning the floor of the quotient.
* <p>
* Unlike the built-in division, this is mathematically well-behaved.
* E.g., <code>-1/4</code> => 0
* but <code>floorDivide(-1,4)</code> => -1.
* @param numerator the numerator
* @param denominator a divisor which must be > 0
* @return the floor of the quotient.
*/
private static final long floorDivide(long numerator, long denominator) {
// We do this computation in order to handle
// a numerator of Long.MIN_VALUE correctly
return (numerator >= 0) ?
numerator / denominator :
((numerator + 1) / denominator) - 1;
}
// public String toString() {
// return "" + month + "/" + day + "/" + year
// + " " + hour + ":" + minute + ":" + second;
// }
/**
* Convert the Julian day, <code>julian</code> into milliseconds.
*
* @param julian Number of days since Jan 1, year 1 (Julian).
* @return the number of millis since the 01/01/1970.
*/
private long julianDayToMillis(long julian) {
return (julian - julianDayOffset) * millisPerDay;
}
/**
* Parse the date string <code>s</code>
*
* @param s a string representation of the date.
*/
private void internalParse(String s) {
int year = -1;
int mon = -1;
int mday = -1;
int hour = -1;
int min = -1;
int sec = -1;
int millis = -1;
int c = -1;
int i = 0;
int n = -1;
int wst = -1;
int tzoffset = -1;
int prevc = 0;
syntax: {
if (s == null)
break syntax;
int limit = s.length();
while (i < limit) {
c = s.charAt(i);
i++;
if (c <= ' ' || c == ',')
continue;
if (c == '(') { // skip comments
int depth = 1;
while (i < limit) {
c = s.charAt(i);
i++;
if (c == '(') depth++;
else if (c == ')')
if (--depth <= 0)
break;
}
continue;
}
if ('0' <= c && c <= '9') {
n = c - '0';
while (i < limit && '0' <= (c = s.charAt(i)) && c <= '9') {
n = n * 10 + c - '0';
i++;
}
if (prevc == '+' || prevc == '-' && year >= 0) {
// timezone offset
if (n < 24)
n = n * 60; // EG. "GMT-3"
else
n = n % 100 + n / 100 * 60; // eg "GMT-0430"
if (prevc == '+') // plus means east of GMT
n = -n;
if (tzoffset != 0 && tzoffset != -1)
break syntax;
tzoffset = n;
} else if (n >= 70)
if (year >= 0)
break syntax;
else if (c <= ' ' || c == ',' || c == '/' || i >= limit)
// year = n < 1900 ? n : n - 1900;
year = n < 100 ? n + 1900 : n;
else
break syntax;
else if (c == ':')
if (hour < 0)
hour = (byte) n;
else if (min < 0)
min = (byte) n;
else
break syntax;
else if (c == '/')
if (mon < 0)
mon = (byte) (n - 1);
else if (mday < 0)
mday = (byte) n;
else
break syntax;
else if (i < limit && c != ',' && c > ' ' && c != '-')
break syntax;
else if (hour >= 0 && min < 0)
min = (byte) n;
else if (min >= 0 && sec < 0)
sec = (byte) n;
else if (mday < 0)
mday = (byte) n;
else
break syntax;
prevc = 0;
} else if (c == '/' || c == ':' || c == '+' || c == '-')
prevc = c;
else {
int st = i - 1;
while (i < limit) {
c = s.charAt(i);
if (!('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'))
break;
i++;
}
if (i <= st + 1)
break syntax;
int k;
for (k = wtb.length; --k >= 0; )
if (wtb[k].regionMatches(true, 0, s, st, i - st)) {
int action = ttb[k];
if (action != 0) {
if (action == 1) { // pm
if (hour > 12 || hour < 1)
break syntax;
else if (hour < 12)
hour += 12;
} else if (action == 14) { // am
if (hour > 12 || hour < 1)
break syntax;
else if (hour == 12)
hour = 0;
} else if (action <= 13) { // month!
if (mon < 0)
mon = (byte) (action - 2);
else
break syntax;
} else {
tzoffset = action - 10000;
}
}
break;
}
if (k < 0)
break syntax;
prevc = 0;
}
}
if (year < 1583 || mon < 0 || mday < 0)
break syntax;
if (sec < 0)
sec = 0;
if (min < 0)
min = 0;
if (hour < 0)
hour = 0;
this.year = year;
month = mon;
day = mday;
this.hour = hour;
this.tzoffset = -tzoffset * 60 * 1000;
minute = min;
second = sec;
milli = 0;
return;
}
// syntax error
throw new IllegalArgumentException();
}
/** A table of valid timezones */
private static Hashtable timezones;
/** Number of days in each month in a non leap year */
private int[] days_in_month = {31, 28, 31, 30, 31, 30, 31,
31, 30, 31, 30, 31};
/** Short versions of the month strings */
private String[] month_shorts = {"Jan", "Feb", "Mar", "Apr",
"May", "Jun", "Jul", "Aug",
"Sep", "Oct", "Nov", "Dec"};
/** Short versions of the weekday strings */
private String[] weekday_shorts = {"Mon", "Tue", "Wed", "Thu",
"Fri", "Sat", "Sun"};
/** Offset from Jan 1, year 1 (Julian) and Jan 1, 1970 */
private static long julianDayOffset = 2440588;
/** Number of milliseconds per hour */
private static int millisPerHour = 60 * 60 * 1000;
/** Number of milliseconds per day */
private static int millisPerDay = 24 * millisPerHour;
/** Jan 1, year 1 (Gregorian) */
private static final int JAN_1_1_JULIAN_DAY = 1721426;
/** All of the valid strings for the date */
private final static String wtb[] = {
"am", "pm",
"monday", "tuesday", "wednesday", "thursday", "friday",
"saturday", "sunday",
"january", "february", "march", "april", "may", "june",
"july", "august", "september", "october", "november", "december",
"gmt", "ut", "utc", "est", "edt", "cst", "cdt",
"mst", "mdt", "pst", "pdt"
// this time zone table needs to be expanded
};
/**
* Used to process date strings. Each value coresponds to a string
* in the wtb variable.
*/
private final static int ttb[] = {
14, 1, 0, 0, 0, 0, 0, 0, 0,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
10000 + 0, 10000 + 0, 10000 + 0, // GMT/UT/UTC
10000 + 5 * 60, 10000 + 4 * 60, // EST/EDT
10000 + 6 * 60, 10000 + 5 * 60,
10000 + 7 * 60, 10000 + 6 * 60,
10000 + 8 * 60, 10000 + 7 * 60
};
/** Cummulative number of days for each month in a non leap year. */
private static final int NUM_DAYS[] = { 0, 31, 59, 90, 120, 151,
181, 212, 243, 273, 304, 334};
/** Cummulative number of days for each month in a leap year. */
private static final int LEAP_NUM_DAYS[] = { 0, 31, 60, 91, 121, 152,
182, 213, 244, 274, 305, 335};
static {
timezones = new Hashtable();
timezones.put("GMT", new Integer(0 * millisPerHour));
timezones.put("UT", new Integer(0 * millisPerHour));
timezones.put("UTC", new Integer(0 * millisPerHour));
timezones.put("PST", new Integer(-8 * millisPerHour));
timezones.put("PDT", new Integer(-7 * millisPerHour));
timezones.put("JST", new Integer(9 * millisPerHour));
local_tz = ((Integer)timezones.get("PST")).intValue();
}
}
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