Package org.threeten.bp.chrono

Interface Era

  • All Superinterfaces:
    TemporalAccessor, TemporalAdjuster
    All Known Implementing Classes:
    DefaultInterfaceEra, HijrahEra, IsoEra, JapaneseEra, MinguoEra, ThaiBuddhistEra
    public interface Era
extends TemporalAccessor, TemporalAdjuster
    An era of the time-line.

    Most calendar systems have a single epoch dividing the time-line into two eras. However, some calendar systems, have multiple eras, such as one for the reign of each leader. In all cases, the era is conceptually the largest division of the time-line. Each chronology defines the Era's that are known Eras and a Chrono.eras to get the valid eras.

    For example, the Thai Buddhist calendar system divides time into two eras, before and after a single date. By contrast, the Japanese calendar system has one era for the reign of each Emperor.

    Instances of Era may be compared using the == operator.

    Specification for implementors

    This interface must be implemented with care to ensure other classes operate correctly. All implementations must be singletons - final, immutable and thread-safe. It is recommended to use an enum whenever possible.

    • Method Detail

      • getValue

        int getValue()
        Gets the numeric value associated with the era as defined by the chronology. Each chronology defines the predefined Eras and methods to list the Eras of the chronology.

        All fields, including eras, have an associated numeric value. The meaning of the numeric value for era is determined by the chronology according to these principles:

        • The era in use at the epoch 1970-01-01 (ISO) has the value 1.
        • Later eras have sequentially higher values.
        • Earlier eras have sequentially lower values, which may be negative.

        Returns:
        the numeric era value

      • getDisplayName

        String getDisplayName​(TextStyle style,
                      Locale locale)
        Gets the textual representation of this era.

        This returns the textual name used to identify the era. The parameters control the style of the returned text and the locale.

        If no textual mapping is found then the numeric value is returned.

        Parameters:
        style - the style of the text required, not null
        locale - the locale to use, not null
        Returns:
        the text value of the era, not null