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Date and Time API

HadjshellLess than 1 minuteNoteLanguageJava
  • Starting time: 1 Jan 1970; starting year for a calendar: 1900
  • Old APIs in java.util
    • Keep timestamp in a long value in milliseconds
    • Is mutable
    • java.util.Date is deprecated
    • java.util.Calendar
      • An abstract class
      • The standard calendar: GregorianCalendar
    • java.util.TimeZone
      • An abstract class
  • New APIs: Joda Date and Time APIs in java.time
    • Date and time are separated
    • Keep timestamp in seconds and nano seconds
    • Is immutable
    • Instant
      • A timestamp
    • LocalDate, LocalTime, LocalDateTime, ZonedDateTime, ZoneID
    • Duration, Period
      • A Duration is a simple measure of time along the time-line in nanoseconds
      • A Period expresses an amount of time in units meaningful to humans, such as years or days
      • between()
    • Month, DayOfWeek, Year, YearMonth, MonthDay, OffsetTime, OffsetDateTime, ZoneOffset
    • Methods
      • of - static factory method
      • now - static factory method
      • parse - static factory method focused on parsing
      • get - gets the value of something
      • is - checks if something is true
      • with - the immutable equivalent of a setter
      • plus - adds an amount to an object
      • minus - subtracts an amount from an object
      • to - converts this object to another type
      • at - combines this object with another
    • All calculations should check for numeric overflow and throw either an ArithmeticException or a DateTimeException
    • DateTimeFormatter
      • ofPattern(String pattern)
      • doc
    • ChronoField