Aus Javadoc zu InstantKlasse
An instantaneous point on the time-line.
(https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html)
Damit ist Instant inetwa sowas wie java.util.Date
Period
A date-based amount of time in the ISO-8601 calendar system, such as ‘2 years, 3 months and 4 days’. This class models a quantity or amount of time in terms of years, months and days. See Duration for the time-based equivalent to this class.
(https://docs.oracle.com/javase/8/docs/api/java/time/Period.html)
Duration
A time-based amount of time, such as ‘34.5 seconds’. This class models a quantity or amount of time in terms of seconds and nanoseconds.
(https://docs.oracle.com/javase/8/docs/api/java/time/Duration.html)
Ein Monat (Period) kann eine Duration zwischen 2886400s = 2419200s und 3186400=2678400s haben (Schalt-Stunden nicht berücksichtigt).
Instant.now();
Instant.ofEpochSecond(120000)
Umwandlung von java.util.Date in Instant und umgekehrt geht mit folgenden Methoden:
java.util.Date.toInstant()
java.util.Date.from(Instant)
Duration duration = Duration.between(Instant.ofEpochSecond(0L), Instant.ofEpochSecond(120000));
System.out.println(duration.toHours()); // 33
Duration duration2 = duration.multipliedBy(2).minusDays(10);
System.out.println(duration2.toHours()); // -173
System.out.println(duration2.isNegative()); // true
In der Klasse Duration gibt es Methoden zum addieren, subtrahieren, multiplizieren von Durations (es wird immer eine neues Duration Objekt erzeugt - Duration ist immutable)
Aus Javadoc zu LocalDate
A date without a time-zone in the ISO-8601 calendar system, such as 2007-12-03.
(https://docs.oracle.com/javase/8/docs/api/java/time/LocalDate.html)
Anders als java.util.Date hat LocalDate
Damit eigenet sich LocalDate deutlich besser für Datumsangaben, z.B. Geburtsdatum
LocalTime
A time without time-zone in the ISO-8601 calendar system, such as 10:15:30.
(https://docs.oracle.com/javase/8/docs/api/java/time/LocalTime.html)
LocalDateTime
A date-time without a time-zone in the ISO-8601 calendar system, such as 2007-12-03T10:15:30.
(https://docs.oracle.com/javase/8/docs/api/java/time/LocalDateTime.html)
LocalDate today = LocalDate.now(); // 2014-07-01
System.out.println(today);
LocalDate date_1 = LocalDate.of(2010, 1, 1); // 2010-01-01
System.out.println(date_1);
LocalDate date_2 = LocalDate.ofYearDay(2010, 100); // 2010-04-10
System.out.println(date_2);
LocalDate date_3 = LocalDate.ofYearDay(2012, 100); // 2012-04-09 (Schaltjahr)
System.out.println(date_3);
LocalDate date_4 = LocalDate.of(2010, Month.FEBRUARY, 10);
System.out.println(date_4);
// java.time.DateTimeException: Invalid date 'FEBRUARY 30'
// LocalDate.of(2010, Month.FEBRUARY, 30);
LocalTime time_1 = LocalTime.now(); // 11:04:35.113
LocalTime time_2 = LocalTime.of(22, 30); // 22:30
LocalTime time_3 = time_2.plusHours(8); // 06:30
System.out.println(time_3.isAfter(time_2)); // false
System.out.println(time_3.isBefore(time_2)); // true
LocalDate date_1 = LocalDate.of(2010, Month.JANUARY, 10); // 2010-03-10
LocalDate date_2 = LocalDate.of(2011, Month.APRIL, 23); // 2011-04-23
Period period = date_1.until(date_2);
System.out.println(period); // P1Y3M13D = 1 Year 3 Month 13 Days
long periodInDays = date_1.until(date_2, ChronoUnit.DAYS);
System.out.println(periodInDays); // 468
Dasselbe in einem Schaltjahr:
LocalDate date_1 = LocalDate.of(2012, Month.JANUARY, 10); // 2012-03-10
LocalDate date_2 = LocalDate.of(2013, Month.APRIL, 23); // 2013-04-23
Period period = date_1.until(date_2);
System.out.println(period); // P1Y3M13D = 1 Year 3 Month 13 Days
long periodInDays = date_1.until(date_2, ChronoUnit.DAYS);
System.out.println(periodInDays); // 469
In diesem Beispiel sieht man sehr schön den Unterschied Period und die Zeitdifferenz in Tagen. Geht die Differenz über den 29. Februar eines Schaltjahres, so bleibt die die Period gleich, die Differenz in Tagen wird aber eins größer (um den 29. Februar).
Javadoc DateTimeFormatter
Formatter for printing and parsing date-time objects. … A formatter created from a pattern can be used as many times as necessary, it is immutable and is thread-safe.
From https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html
Man beachte die Unterschiede bei ZonedDateTime und LocalDateTime!
DateTimeFormatter.ISO_DATE_TIME.format(LocalDateTime.now()); // 2014-07-22T15:18:47.328
DateTimeFormatter.ISO_DATE_TIME.format(ZonedDateTime.now()); // 2014-07-22T15:18:47.328+02:00[Europe/Berlin]
DateTimeFormatter.ISO_ZONED_DATE_TIME.format(ZonedDateTime.now()); // 2014-07-22T15:18:47.328+02:00[Europe/Berlin]
DateTimeFormatter.ISO_LOCAL_DATE.format(LocalDate.now()); // 2014-07-22
DateTimeFormatter.ISO_DATE.format(ZonedDateTime.now()); // 2014-07-22+02:00
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL);
formatter.format(ZonedDateTime.now()); // Dienstag, 22. Juli 2014 15:24 Uhr MESZ
// LocalDateTime nur SHORT, MEDIUM, für Long, FULL kann keine Zeitzone bestimmt werden ;
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM);
formatter.format(LocalDateTime.now()); // 22.07.2014 15:24:56
DateTimeFormatter.ofPattern("dd.MM.yyyy", Locale.GERMANY).format(LocalDate.now()); // 22.07.2014
DateTimeFormatter.ofPattern("dd.MM.yyyy", Locale.GERMANY).format(ZonedDateTime.now()); // 2014-07-22+02:00
LocalDate date = LocalDate.parse("22.07.2014", DateTimeFormatter.ofPattern("dd.MM.yyyy")); // 2014-07-22
Adjusters are a key tool for modifying temporal objects.
(https://docs.oracle.com/javase/8/docs/api/java/time/temporal/TemporalAdjuster.html)
Man kann damit neue temporale Objekte erzeugen, die in Beziehung zum Ausgangsobjet stehen, z.B.
LocalDate date_1 = LocalDate.of(2010, Month.FEBRUARY, 10); // 2010-02-10
LocalDate date_2 = date_1.with(TemporalAdjusters.nextOrSame(DayOfWeek.MONDAY)); // 2010-02-15
LocalDate date_3 = date_1.with(TemporalAdjusters.firstDayOfNextMonth()); // 2010-03-01