Source Code Cross Referenced for DateValue.java in  » XML » XPath-Saxon » net » sf » saxon » value » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Java Source Code / Java Documentation
1. 6.0 JDK Core
2. 6.0 JDK Modules
3. 6.0 JDK Modules com.sun
4. 6.0 JDK Modules com.sun.java
5. 6.0 JDK Modules sun
6. 6.0 JDK Platform
7. Ajax
8. Apache Harmony Java SE
9. Aspect oriented
10. Authentication Authorization
11. Blogger System
12. Build
13. Byte Code
14. Cache
15. Chart
16. Chat
17. Code Analyzer
18. Collaboration
19. Content Management System
20. Database Client
21. Database DBMS
22. Database JDBC Connection Pool
23. Database ORM
24. Development
25. EJB Server geronimo
26. EJB Server GlassFish
27. EJB Server JBoss 4.2.1
28. EJB Server resin 3.1.5
29. ERP CRM Financial
30. ESB
31. Forum
32. GIS
33. Graphic Library
34. Groupware
35. HTML Parser
36. IDE
37. IDE Eclipse
38. IDE Netbeans
39. Installer
40. Internationalization Localization
41. Inversion of Control
42. Issue Tracking
43. J2EE
44. JBoss
45. JMS
46. JMX
47. Library
48. Mail Clients
49. Net
50. Parser
51. PDF
52. Portal
53. Profiler
54. Project Management
55. Report
56. RSS RDF
57. Rule Engine
58. Science
59. Scripting
60. Search Engine
61. Security
62. Sevlet Container
63. Source Control
64. Swing Library
65. Template Engine
66. Test Coverage
67. Testing
68. UML
69. Web Crawler
70. Web Framework
71. Web Mail
72. Web Server
73. Web Services
74. Web Services apache cxf 2.0.1
75. Web Services AXIS2
76. Wiki Engine
77. Workflow Engines
78. XML
79. XML UI
Java
Java Tutorial
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Source Code / Java Documentation » XML » XPath Saxon » net.sf.saxon.value 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        package net.sf.saxon.value;
002:
003:        import net.sf.saxon.Err;
004:        import net.sf.saxon.expr.XPathContext;
005:        import net.sf.saxon.functions.Component;
006:        import net.sf.saxon.om.FastStringBuffer;
007:        import net.sf.saxon.trans.DynamicError;
008:        import net.sf.saxon.trans.IndependentContext;
009:        import net.sf.saxon.trans.XPathException;
010:        import net.sf.saxon.type.*;
011:
012:        import java.util.*;
013:
014:        /**
015:         * A value of type Date. Note that a Date may include a TimeZone.
016:         */
017:
018:        public class DateValue extends CalendarValue {
019:
020:            protected int year; // unlike the lexical representation, includes a year zero
021:            protected byte month;
022:            protected byte day;
023:
024:            /**
025:             * Default constructor needed for subtyping
026:             */
027:
028:            protected DateValue() {
029:            }
030:
031:            /**
032:             * Constructor given a year, month, and day. Performs no validation.
033:             */
034:
035:            protected DateValue(int year, byte month, byte day) {
036:                this .year = year;
037:                this .month = month;
038:                this .day = day;
039:            }
040:
041:            /**
042:             * Constructor given a year, month, and day, and timezone. Performs no validation.
043:             */
044:
045:            protected DateValue(int year, byte month, byte day, int tz) {
046:                this .year = year;
047:                this .month = month;
048:                this .day = day;
049:                setTimezoneInMinutes(tz);
050:            }
051:
052:            /**
053:             * Constructor: create a dateTime value from a supplied string, in
054:             * ISO 8601 format
055:             */
056:            public DateValue(CharSequence s) throws XPathException {
057:                setLexicalValue(s);
058:            }
059:
060:            /**
061:             * Create a DateValue
062:             * @param calendar the absolute date/time value
063:             * @param tz the timezone offset from UTC in minutes
064:             */
065:            public DateValue(GregorianCalendar calendar, int tz) {
066:                int era = calendar.get(GregorianCalendar.ERA);
067:                year = calendar.get(Calendar.YEAR);
068:                if (era == GregorianCalendar.BC) {
069:                    year = -year;
070:                }
071:                month = (byte) (calendar.get(Calendar.MONTH) + 1);
072:                day = (byte) (calendar.get(Calendar.DATE));
073:                setTimezoneInMinutes(tz);
074:            }
075:
076:            /**
077:             * Initialize the DateValue using a character string in the format yyyy-mm-dd and an optional time zone.
078:             * Input must have format [+|-]yyyy-mm-dd[([+|-]hh:mm | Z)]
079:             * @param s the supplied string value
080:             * @throws net.sf.saxon.trans.XPathException
081:             */
082:            public void setLexicalValue(CharSequence s) throws XPathException {
083:                StringTokenizer tok = new StringTokenizer(trimWhitespace(s)
084:                        .toString(), "-:+Z", true);
085:                try {
086:                    if (!tok.hasMoreElements())
087:                        badDate("Too short", s);
088:                    String part = (String) tok.nextElement();
089:                    int era = +1;
090:                    if ("+".equals(part)) {
091:                        part = (String) tok.nextElement();
092:                    } else if ("-".equals(part)) {
093:                        era = -1;
094:                        part = (String) tok.nextElement();
095:                    }
096:
097:                    if (part.length() < 4)
098:                        badDate("Year is less than four digits", s);
099:                    year = Integer.parseInt(part) * era;
100:                    if (year == 0)
101:                        badDate("Year zero is not allowed", s);
102:                    if (era < 0) {
103:                        year++; // internal representation allows a year zero.
104:                    }
105:                    if (!tok.hasMoreElements())
106:                        badDate("Too short", s);
107:                    if (!"-".equals(tok.nextElement()))
108:                        badDate("Wrong delimiter after year", s);
109:
110:                    if (!tok.hasMoreElements())
111:                        badDate("Too short", s);
112:                    part = (String) tok.nextElement();
113:                    if (part.length() != 2)
114:                        badDate("Month must be two digits", s);
115:                    month = (byte) Integer.parseInt(part);
116:                    if (month < 1 || month > 12)
117:                        badDate("Month is out of range", s);
118:                    if (!tok.hasMoreElements())
119:                        badDate("Too short", s);
120:                    if (!"-".equals(tok.nextElement()))
121:                        badDate("Wrong delimiter after month", s);
122:
123:                    if (!tok.hasMoreElements())
124:                        badDate("Too short", s);
125:                    part = (String) tok.nextElement();
126:                    if (part.length() != 2)
127:                        badDate("Day must be two digits", s);
128:                    day = (byte) Integer.parseInt(part);
129:                    if (day < 1 || day > 31)
130:                        badDate("Day is out of range", s);
131:
132:                    int tzOffset;
133:                    if (tok.hasMoreElements()) {
134:
135:                        String delim = (String) tok.nextElement();
136:
137:                        if ("Z".equals(delim)) {
138:                            tzOffset = 0;
139:                            if (tok.hasMoreElements())
140:                                badDate("Continues after 'Z'", s);
141:                            setTimezoneInMinutes(tzOffset);
142:
143:                        } else if (!(!"+".equals(delim) && !"-".equals(delim))) {
144:                            if (!tok.hasMoreElements())
145:                                badDate("Missing timezone", s);
146:                            part = (String) tok.nextElement();
147:                            int tzhour = Integer.parseInt(part);
148:                            if (part.length() != 2)
149:                                badDate("Timezone hour must be two digits", s);
150:                            if (tzhour > 14)
151:                                badDate("Timezone hour is out of range", s);
152:                            //if (tzhour > 12) badDate("Because of Java limitations, Saxon currently limits the timezone to +/- 12 hours", s);
153:                            if (!tok.hasMoreElements())
154:                                badDate("No minutes in timezone", s);
155:                            if (!":".equals(tok.nextElement()))
156:                                badDate("Wrong delimiter after timezone hour",
157:                                        s);
158:
159:                            if (!tok.hasMoreElements())
160:                                badDate("No minutes in timezone", s);
161:                            part = (String) tok.nextElement();
162:                            int tzminute = Integer.parseInt(part);
163:                            if (part.length() != 2)
164:                                badDate("Timezone minute must be two digits", s);
165:                            if (tzminute > 59)
166:                                badDate("Timezone minute is out of range", s);
167:                            if (tok.hasMoreElements())
168:                                badDate("Continues after timezone", s);
169:
170:                            tzOffset = (tzhour * 60 + tzminute);
171:                            if ("-".equals(delim))
172:                                tzOffset = -tzOffset;
173:                            setTimezoneInMinutes(tzOffset);
174:
175:                        } else {
176:                            badDate("Timezone format is incorrect", s);
177:                        }
178:                    }
179:
180:                    if (!isValidDate(year, month, day)) {
181:                        badDate("Non-existent date", s);
182:                    }
183:
184:                } catch (NumberFormatException err) {
185:                    badDate("Non-numeric component", s);
186:                }
187:            }
188:
189:            private void badDate(String msg, CharSequence value)
190:                    throws ValidationException {
191:                ValidationException err = new ValidationException(
192:                        "Invalid date " + Err.wrap(value, Err.VALUE) + ". "
193:                                + msg);
194:                err.setErrorCode("FORG0001");
195:                throw err;
196:            }
197:
198:            /**
199:             * Get the year component of the date (in local form)
200:             */
201:
202:            public int getYear() {
203:                return year;
204:            }
205:
206:            /**
207:             * Get the month component of the date (in local form)
208:             */
209:
210:            public byte getMonth() {
211:                return month;
212:            }
213:
214:            /**
215:             * Get the day component of the date (in local form)
216:             */
217:
218:            public byte getDay() {
219:                return day;
220:            }
221:
222:            /**
223:             * Test whether a candidate date is actually a valid date in the proleptic Gregorian calendar
224:             */
225:
226:            private static byte[] daysPerMonth = { 31, 28, 31, 30, 31, 30, 31,
227:                    31, 30, 31, 30, 31 };
228:
229:            public static boolean isValidDate(int year, int month, int day) {
230:                if (month > 0 && month <= 12 && day > 0
231:                        && day <= daysPerMonth[month - 1]) {
232:                    return true;
233:                }
234:                if (month == 2 && day == 29) {
235:                    return isLeapYear(year);
236:                }
237:                return false;
238:            }
239:
240:            /**
241:             * Test whether a year is a leap year
242:             */
243:
244:            public static boolean isLeapYear(int year) {
245:                return (year % 4 == 0)
246:                        && !(year % 100 == 0 && !(year % 400 == 0));
247:            }
248:
249:            /**
250:             * Get the date that immediately follows a given date
251:             * @return a new DateValue with no timezone information
252:             */
253:
254:            public static DateValue tomorrow(int year, byte month, byte day) {
255:                if (DateValue.isValidDate(year, month, day + 1)) {
256:                    return new DateValue(year, month, (byte) (day + 1));
257:                } else if (month < 12) {
258:                    return new DateValue(year, (byte) (month + 1), (byte) 1);
259:                } else {
260:                    return new DateValue(year + 1, (byte) 1, (byte) 1);
261:                }
262:            }
263:
264:            /**
265:             * Get the date that immediately precedes a given date
266:             * @return a new DateValue with no timezone information
267:             */
268:
269:            public static DateValue yesterday(int year, byte month, byte day) {
270:                if (day > 1) {
271:                    return new DateValue(year, month, (byte) (day - 1));
272:                } else if (month > 1) {
273:                    if (month == 3 && isLeapYear(year)) {
274:                        return new DateValue(year, (byte) 2, (byte) 29);
275:                    } else {
276:                        return new DateValue(year, (byte) (month - 1),
277:                                daysPerMonth[month - 2]);
278:                    }
279:                } else {
280:                    return new DateValue(year - 1, (byte) 12, (byte) 31);
281:                }
282:            }
283:
284:            /**
285:             * Convert to target data type
286:             * @param requiredType an integer identifying the required atomic type
287:             * @param context
288:             * @return an AtomicValue, a value of the required type; or an ErrorValue
289:             */
290:
291:            public AtomicValue convertPrimitive(BuiltInAtomicType requiredType,
292:                    boolean validate, XPathContext context) {
293:                switch (requiredType.getPrimitiveType()) {
294:                case Type.DATE:
295:                case Type.ANY_ATOMIC:
296:                case Type.ITEM:
297:                    return this ;
298:                case Type.DATE_TIME:
299:                    return toDateTime();
300:
301:                case Type.STRING:
302:                    return new StringValue(getStringValueCS());
303:
304:                case Type.UNTYPED_ATOMIC:
305:                    return new UntypedAtomicValue(getStringValueCS());
306:
307:                case Type.G_YEAR: {
308:                    return new GYearValue(year, getTimezoneInMinutes());
309:                }
310:                case Type.G_YEAR_MONTH: {
311:                    return new GYearMonthValue(year, month,
312:                            getTimezoneInMinutes());
313:                }
314:                case Type.G_MONTH: {
315:                    return new GMonthValue(month, getTimezoneInMinutes());
316:                }
317:                case Type.G_MONTH_DAY: {
318:                    return new GMonthDayValue(month, day,
319:                            getTimezoneInMinutes());
320:                }
321:                case Type.G_DAY: {
322:                    return new GDayValue(day, getTimezoneInMinutes());
323:                }
324:
325:                default:
326:                    ValidationException err = new ValidationException(
327:                            "Cannot convert date to "
328:                                    + requiredType.getDisplayName());
329:                    err.setErrorCode("XPTY0004");
330:                    err.setIsTypeError(true);
331:                    return new ValidationErrorValue(err);
332:                }
333:            }
334:
335:            /**
336:             * Convert to DateTime
337:             */
338:
339:            public DateTimeValue toDateTime() {
340:                return new DateTimeValue(year, month, day, (byte) 0, (byte) 0,
341:                        (byte) 0, 0, getTimezoneInMinutes());
342:            }
343:
344:            /**
345:             * Convert to string
346:             * @return ISO 8601 representation.
347:             */
348:
349:            public CharSequence getStringValueCS() {
350:
351:                FastStringBuffer sb = new FastStringBuffer(16);
352:                int yr = year;
353:                if (year <= 0) {
354:                    sb.append('-');
355:                    yr = -yr + 1; // no year zero in lexical space
356:                }
357:                appendString(sb, yr, (yr > 9999 ? (yr + "").length() : 4));
358:                sb.append('-');
359:                appendTwoDigits(sb, month);
360:                sb.append('-');
361:                appendTwoDigits(sb, day);
362:
363:                if (hasTimezone()) {
364:                    appendTimezone(sb);
365:                }
366:
367:                return sb;
368:
369:            }
370:
371:            public GregorianCalendar getCalendar() {
372:
373:                int tz = (hasTimezone() ? getTimezoneInMinutes() : 0);
374:                TimeZone zone = new SimpleTimeZone(tz * 60000, "LLL");
375:                GregorianCalendar calendar = new GregorianCalendar(zone);
376:                calendar.clear();
377:                calendar.setLenient(false);
378:                calendar.set(Math.abs(year), month - 1, day);
379:                calendar.set(Calendar.ZONE_OFFSET, tz * 60000);
380:                calendar.set(Calendar.DST_OFFSET, 0);
381:                if (year < 0) {
382:                    calendar.set(Calendar.ERA, GregorianCalendar.BC);
383:                }
384:                calendar.getTime();
385:                return calendar;
386:            }
387:
388:            /**
389:             * Determine the data type of the expression
390:             * @return Type.DATE_TYPE,
391:             * @param th
392:             */
393:
394:            public ItemType getItemType(TypeHierarchy th) {
395:                return Type.DATE_TYPE;
396:            }
397:
398:            /**
399:             * Make a copy of this date, time, or dateTime value
400:             */
401:
402:            public CalendarValue copy() {
403:                return new DateValue(year, month, day, getTimezoneInMinutes());
404:            }
405:
406:            /**
407:             * Return a new date with the same normalized value, but
408:             * in a different timezone. This is called only for a DateValue that has an explicit timezone
409:             * @param timezone the new timezone offset, in minutes
410:             * @return the time in the new timezone. This will be a new TimeValue unless no change
411:             * was required to the original value
412:             */
413:
414:            public CalendarValue adjustTimezone(int timezone) {
415:                DateTimeValue dt = (DateTimeValue) toDateTime().adjustTimezone(
416:                        timezone);
417:                return new DateValue(dt.getYear(), dt.getMonth(), dt.getDay(),
418:                        dt.getTimezoneInMinutes());
419:            }
420:
421:            /**
422:             * Convert to Java object (for passing to external functions)
423:             */
424:
425:            public Object convertToJava(Class target, XPathContext context)
426:                    throws XPathException {
427:                if (target.isAssignableFrom(Date.class)) {
428:                    return getCalendar().getTime();
429:                } else if (target.isAssignableFrom(GregorianCalendar.class)) {
430:                    return getCalendar();
431:                } else if (target.isAssignableFrom(DateTimeValue.class)) {
432:                    return this ;
433:                } else if (target == String.class
434:                        || target == CharSequence.class) {
435:                    return getStringValue();
436:                } else if (target == Object.class) {
437:                    return getStringValue();
438:                } else {
439:                    Object o = super .convertToJava(target, context);
440:                    if (o == null) {
441:                        throw new DynamicError("Conversion of date to "
442:                                + target.getName() + " is not supported");
443:                    }
444:                    return o;
445:                }
446:            }
447:
448:            /**
449:             * Get a component of the value. Returns null if the timezone component is
450:             * requested and is not present.
451:             */
452:
453:            public AtomicValue getComponent(int component)
454:                    throws XPathException {
455:                switch (component) {
456:                case Component.YEAR:
457:                    return new IntegerValue((year > 0 ? year : year - 1));
458:                case Component.MONTH:
459:                    return new IntegerValue(month);
460:                case Component.DAY:
461:                    return new IntegerValue(day);
462:                case Component.TIMEZONE:
463:                    if (hasTimezone()) {
464:                        return SecondsDurationValue
465:                                .fromMilliseconds(getTimezoneInMinutes() * 60000);
466:                    } else {
467:                        return null;
468:                    }
469:                default:
470:                    throw new IllegalArgumentException(
471:                            "Unknown component for date: " + component);
472:                }
473:            }
474:
475:            /**
476:             * Compare the value to another date value. This method is used only during schema processing,
477:             * and uses XML Schema semantics rather than XPath semantics.
478:             * @param other The other date value. Must be an object of class DateValue.
479:             * @return negative value if this one is the earlier, 0 if they are chronologically equal,
480:             * positive value if this one is the later. For this purpose, dateTime values with an unknown
481:             * timezone are considered to be UTC values (the Comparable interface requires
482:             * a total ordering).
483:             * @throws ClassCastException if the other value is not a DateValue (the parameter
484:             * is declared as Object to satisfy the Comparable interface)
485:             */
486:
487:            public int compareTo(Object other) {
488:                if (!(other instanceof  DateValue)) {
489:                    throw new ClassCastException(
490:                            "Date values are not comparable to "
491:                                    + other.getClass());
492:                }
493:                return compareTo((DateValue) other, new IndependentContext()
494:                        .makeEarlyEvaluationContext());
495:            }
496:
497:            /**
498:             * Compare this value to another value of the same type, using the supplied context object
499:             * to get the implicit timezone if required. This method implements the XPath comparison semantics.
500:             */
501:
502:            public int compareTo(CalendarValue other, XPathContext context) {
503:                final TypeHierarchy th = context.getNamePool()
504:                        .getTypeHierarchy();
505:                if (this .getItemType(th).getPrimitiveType() != other
506:                        .getItemType(th).getPrimitiveType()) {
507:                    throw new ClassCastException(
508:                            "Cannot compare values of different types");
509:                    // covers, for example, comparing a gYear to a gYearMonth
510:                }
511:                // This code allows comparison of a gYear (etc) to a date, but this is prevented at a higher level
512:                return toDateTime().compareTo(other.toDateTime(), context);
513:            }
514:
515:            public boolean equals(Object other) {
516:                return compareTo(other) == 0;
517:            }
518:
519:            public int hashCode() {
520:                // Equality must imply same hashcode, but not vice-versa
521:                return getCalendar().getTime().hashCode()
522:                        + getTimezoneInMinutes();
523:            }
524:
525:            /**
526:             * Add a duration to a date
527:             * @param duration the duration to be added (may be negative)
528:             * @return the new date
529:             * @throws net.sf.saxon.trans.XPathException if the duration is an xs:duration, as distinct from
530:             * a subclass thereof
531:             */
532:
533:            public CalendarValue add(DurationValue duration)
534:                    throws XPathException {
535:                if (duration instanceof  SecondsDurationValue) {
536:                    long microseconds = ((SecondsDurationValue) duration)
537:                            .getLengthInMicroseconds();
538:                    boolean negative = (microseconds < 0);
539:                    microseconds = Math.abs(microseconds);
540:                    int days = (int) Math.floor((double) microseconds
541:                            / (1000000L * 60L * 60L * 24L));
542:                    boolean partDay = (microseconds % (1000000L * 60L * 60L * 24L)) > 0;
543:                    int julian = getJulianDayNumber(year, month, day);
544:                    DateValue d = dateFromJulianDayNumber(julian
545:                            + (negative ? -days : days));
546:                    if (partDay) {
547:                        if (negative) {
548:                            d = yesterday(d.year, d.month, d.day);
549:                        }
550:                    }
551:                    d.setTimezoneInMinutes(getTimezoneInMinutes());
552:                    return d;
553:                } else if (duration instanceof  MonthDurationValue) {
554:                    int months = ((MonthDurationValue) duration)
555:                            .getLengthInMonths();
556:                    int m = (month - 1) + months;
557:                    int y = year + m / 12;
558:                    m = m % 12;
559:                    if (m < 0) {
560:                        m += 12;
561:                        y -= 1;
562:                    }
563:                    m++;
564:                    int d = day;
565:                    while (!isValidDate(y, m, d)) {
566:                        d -= 1;
567:                    }
568:                    return new DateValue(y, (byte) m, (byte) d,
569:                            getTimezoneInMinutes());
570:                } else {
571:                    DynamicError err = new DynamicError(
572:                            "Date arithmetic is not supported on xs:duration, only on its subtypes");
573:                    err.setIsTypeError(true);
574:                    err.setErrorCode("XPTY0004");
575:                    throw err;
576:                }
577:            }
578:
579:            /**
580:             * Determine the difference between two points in time, as a duration
581:             * @param other the other point in time
582:             * @param context
583:             * @return the duration as an xdt:dayTimeDuration
584:             * @throws net.sf.saxon.trans.XPathException for example if one value is a date and the other is a time
585:             */
586:
587:            public SecondsDurationValue subtract(CalendarValue other,
588:                    XPathContext context) throws XPathException {
589:                if (!(other instanceof  DateValue)) {
590:                    DynamicError err = new DynamicError(
591:                            "First operand of '-' is a date, but the second is not");
592:                    err.setIsTypeError(true);
593:                    err.setErrorCode("XPTY0004");
594:                    throw err;
595:                }
596:                return super .subtract(other, context);
597:            }
598:
599:            /**
600:             * Calculate the Julian day number at 00:00 on a given date. This algorithm is taken from
601:             * http://vsg.cape.com/~pbaum/date/jdalg.htm and
602:             * http://vsg.cape.com/~pbaum/date/jdalg2.htm
603:             * (adjusted to handle BC dates correctly)
604:             */
605:
606:            public static int getJulianDayNumber(int year, int month, int day) {
607:                int z = year - (month < 3 ? 1 : 0);
608:                short f = monthData[month - 1];
609:                if (z >= 0) {
610:                    return day + f + 365 * z + z / 4 - z / 100 + z / 400
611:                            + 1721118;
612:                } else {
613:                    // for negative years, add 12000 years and then subtract the days!
614:                    z += 12000;
615:                    int j = day + f + 365 * z + z / 4 - z / 100 + z / 400
616:                            + 1721118;
617:                    return j
618:                            - (365 * 12000 + 12000 / 4 - 12000 / 100 + 12000 / 400); // number of leap years in 12000 years
619:                }
620:            }
621:
622:            /**
623:             * Get the Gregorian date corresponding to a particular Julian day number. The algorithm
624:             * is taken from http://www.hermetic.ch/cal_stud/jdn.htm#comp
625:             * @return a DateValue with no timezone information set
626:             */
627:
628:            public static DateValue dateFromJulianDayNumber(int julianDayNumber) {
629:                if (julianDayNumber >= 0) {
630:                    int L = julianDayNumber + 68569 + 1; // +1 adjustment for days starting at noon
631:                    int n = (4 * L) / 146097;
632:                    L = L - (146097 * n + 3) / 4;
633:                    int i = (4000 * (L + 1)) / 1461001;
634:                    L = L - (1461 * i) / 4 + 31;
635:                    int j = (80 * L) / 2447;
636:                    int d = L - (2447 * j) / 80;
637:                    L = j / 11;
638:                    int m = j + 2 - (12 * L);
639:                    int y = 100 * (n - 49) + i + L;
640:                    return new DateValue(y, (byte) m, (byte) d);
641:                } else {
642:                    // add 12000 years and subtract them again...
643:                    DateValue dt = dateFromJulianDayNumber(julianDayNumber
644:                            + (365 * 12000 + 12000 / 4 - 12000 / 100 + 12000 / 400));
645:                    dt.year -= 12000;
646:                    return dt;
647:                }
648:            }
649:
650:            private static final short[] monthData = { 306, 337, 0, 31, 61, 92,
651:                    122, 153, 184, 214, 245, 275 };
652:
653:            /**
654:             * Get the ordinal day number within the year (1 Jan = 1, 1 Feb = 32, etc)
655:             */
656:
657:            public static final int getDayWithinYear(int year, int month,
658:                    int day) {
659:                int j = getJulianDayNumber(year, month, day);
660:                int k = getJulianDayNumber(year, 1, 1);
661:                return j - k + 1;
662:            }
663:
664:            /**
665:             * Get the day of the week.  The days of the week are numbered from
666:             * 1 (Monday) to 7 (Sunday)
667:             */
668:
669:            public static final int getDayOfWeek(int year, int month, int day) {
670:                int d = getJulianDayNumber(year, month, day);
671:                d -= 2378500; // 1800-01-05 - any Monday would do
672:                while (d <= 0) {
673:                    d += 70000000; // any sufficiently-high multiple of 7 would do
674:                }
675:                return (d - 1) % 7 + 1;
676:            }
677:
678:            /**
679:             * Get the ISO week number for a given date.  The days of the week are numbered from
680:             * 1 (Monday) to 7 (Sunday), and week 1 in any calendar year is the week (from Monday to Sunday)
681:             * that includes the first Thursday of that year
682:             */
683:
684:            public static final int getWeekNumber(int year, int month, int day) {
685:                int d = getDayWithinYear(year, month, day);
686:                int firstDay = getDayOfWeek(year, 1, 1);
687:                if (firstDay > 4 && (firstDay + d) <= 8) {
688:                    // days before week one are part of the last week of the previous year (52 or 53)
689:                    return getWeekNumber(year - 1, 12, 31);
690:                }
691:                int inc = (firstDay < 5 ? 1 : 0); // implements the First Thursday rule
692:                return ((d + firstDay - 2) / 7) + inc;
693:
694:            }
695:
696:            /**
697:             * Get the week number within a month. This is required for the XSLT format-date() function,
698:             * and the rules are not entirely clear. The days of the week are numbered from
699:             * 1 (Monday) to 7 (Sunday), and by analogy with the ISO week number, we consider that week 1
700:             * in any calendar month is the week (from Monday to Sunday) that includes the first Thursday
701:             * of that month. Unlike the ISO week number, we put the previous days in week zero.
702:             */
703:
704:            public static final int getWeekNumberWithinMonth(int year,
705:                    int month, int day) {
706:                int firstDay = getDayOfWeek(year, month, 1);
707:                int inc = (firstDay < 5 ? 1 : 0); // implements the First Thursday rule
708:                return ((day + firstDay - 2) / 7) + inc;
709:            }
710:
711:            /**
712:             * Temporary test rig
713:             */
714:
715:            public static void main(String[] args) throws Exception {
716:                DateValue date = new DateValue(args[0]);
717:                System.out.println(date.getStringValue());
718:                int jd = getJulianDayNumber(date.year, date.month, date.day);
719:                System.out.println(jd);
720:                System.out
721:                        .println(dateFromJulianDayNumber(jd).getStringValue());
722:            }
723:
724:        }
725:
726:        //
727:        // The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
728:        // you may not use this file except in compliance with the License. You may obtain a copy of the
729:        // License at http://www.mozilla.org/MPL/
730:        //
731:        // Software distributed under the License is distributed on an "AS IS" basis,
732:        // WITHOUT WARRANTY OF ANY KIND, either express or implied.
733:        // See the License for the specific language governing rights and limitations under the License.
734:        //
735:        // The Original Code is: all this file.
736:        //
737:        // The Initial Developer of the Original Code is Michael H. Kay
738:        //
739:        // Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
740:        //
741:        // Contributor(s): none.
742:        //
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.