20230522 java.time.LocalDate

介紹

• java.time.LocalDate
• 類聲明

@jdk.internal.ValueBased
public final class LocalDate implements Temporal, TemporalAdjuster, ChronoLocalDate, Serializable

• 本地日期
• 實現 Temporal ，支持的時間單位( TemporalUnit )有
  • DAYS
  • WEEKS
  • MONTHS
  • YEARS
  • DECADES
    • 10年
  • CENTURIES
    • 100年
  • MILLENNIA
    • 1000年
  • ERAS
    • 時代，10億年
• 實現 TemporalAccessor ，支持的時間域( TemporalField )有
  • DAY_OF_WEEK
  • ALIGNED_DAY_OF_WEEK_IN_MONTH
  • ALIGNED_DAY_OF_WEEK_IN_YEAR
  • DAY_OF_MONTH
  • DAY_OF_YEAR
  • EPOCH_DAY
  • ALIGNED_WEEK_OF_MONTH
  • ALIGNED_WEEK_OF_YEAR
  • MONTH_OF_YEAR
  • PROLEPTIC_MONTH
  • YEAR_OF_ERA
  • YEAR
  • ERA
• 內部存儲是

private final int year;
private final short month;
private final short day;

API

常量

• MIN : -999999999-01-01
• MAX : [phone]
• EPOCH : 1970-01-01

static

• now
• of
  • LocalDate of(int year, Month month, int dayOfMonth
  • LocalDate of(int year, int month, int dayOfMonth)
  • year : 2023 表示 2023年
  • month : 1-12
  • dayOfMonth : 1-31
• ofYearDay
  • LocalDate ofYearDay(int year, int dayOfYear)
• ofInstant
  • LocalDate ofInstant(Instant instant, ZoneId zone)
• ofEpochDay
  • 反 toEpochDay
  • 大紀元日第 0 天是 1970-01-01 (ISO)
• from
  • LocalDate from(TemporalAccessor temporal)
• parse
  • 反 toString
  • 格式示例：2023-06-30

public

• toEpochSecond

• datesUntil

  • Stream<LocalDate> datesUntil(LocalDate endExclusive)
  • Stream<LocalDate> datesUntil(LocalDate endExclusive, Period step)

• toString

  • ISO-8601 格式 uuuu-MM-dd

get

• getYear
• getMonthValue
• getMonth
• getDayOfMonth
• getDayOfYear
• getDayOfWeek

plus

• plusYears
• plusMonths
• plusWeeks
• plusDays
• minusYears
• minusMonths
• minusWeeks
• minusDays

with

with：在複製對象的基礎上修改

• withYear
• withMonth
• withDayOfMonth
• withDayOfYear

at

at：結合入參形成新類型

• atTime
  • LocalDateTime atTime(int hour, int minute)
  • LocalDateTime atTime(int hour, int minute, int second)
  • LocalDateTime atTime(int hour, int minute, int second, int nanoOfSecond)
  • OffsetDateTime atTime(OffsetTime time)
• atStartOfDay
  • LocalDateTime atStartOfDay()
  • ZonedDateTime atStartOfDay(ZoneId zone)