Package org.joda.time

Class Instant

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<ReadableInstant>, ReadableInstant
    public final class Instant
extends AbstractInstant
implements ReadableInstant, java.io.Serializable
    Instant is the standard implementation of a fully immutable instant in time.

    Instant is an implementation of ReadableInstant. As with all instants, it represents an exact point on the time-line, but limited to the precision of milliseconds. An Instant should be used to represent a point in time irrespective of any other factor, such as chronology or time zone.

    Internally, the class holds one piece of data, the instant as milliseconds from the Java epoch of 1970-01-01T00:00:00Z.

    For example, an Instant can be used to compare two DateTime objects irrespective of chronology or time zone. 

     boolean sameInstant = dt1.toInstant().equals(dt2.toInstant());
    Note that the following code will also perform the same check: 
     boolean sameInstant = dt1.isEqual(dt2);

    Instant is thread-safe and immutable.

    Since:
    1.0
    See Also:
    Serialized Form

    • Field Detail

      • EPOCH

        public static final Instant EPOCH
        The Java epoch of 1970-01-01T00:00:00Z.
        Since:
        2.10

    • Constructor Detail

      • Instant

        public Instant()
        Constructs an instance set to the current system millisecond time.
        See Also:
        now()

      • Instant

        public Instant​(long instant)
        Constructs an instance set to the milliseconds from 1970-01-01T00:00:00Z.
        Parameters:
        instant - the milliseconds from 1970-01-01T00:00:00Z

      • Instant

        public Instant​(java.lang.Object instant)
        Constructs an instance from an Object that represents a datetime.

        The recognised object types are defined in ConverterManager and include String, Calendar and Date.

        Parameters:
        instant - the datetime object, null means now
        Throws:
        java.lang.IllegalArgumentException - if the instant is invalid

    • Method Detail

      • now

        public static Instant now()
        Obtains an Instant set to the current system millisecond time.
        Returns:
        the current instant, not null
        Since:
        2.0

      • ofEpochMilli

        public static Instant ofEpochMilli​(long epochMilli)
        Obtains an Instant set to the milliseconds from 1970-01-01T00:00:00Z.
        Parameters:
        epochMilli - the milliseconds from 1970-01-01T00:00:00Z
        Since:
        2.10

      • ofEpochSecond

        public static Instant ofEpochSecond​(long epochSecond)
        Obtains an Instant set to the seconds from 1970-01-01T00:00:00Z.
        Parameters:
        epochSecond - the seconds from 1970-01-01T00:00:00Z
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long
        Since:
        2.10

      • parse

        public static Instant parse​(java.lang.String str)
        Parses an Instant from the specified string.

        This uses ISODateTimeFormat.dateTimeParser().

        Parameters:
        str - the string to parse, not null
        Since:
        2.0

      • parse

        public static Instant parse​(java.lang.String str,
                            DateTimeFormatter formatter)
        Parses an Instant from the specified string using a formatter.
        Parameters:
        str - the string to parse, not null
        formatter - the formatter to use, not null
        Since:
        2.0

      • withMillis

        public Instant withMillis​(long newMillis)
        Gets a copy of this instant with different millis.

        The returned object will be either be a new Instant or this.

        Note that this replaces the entire state of the Instant. To manage the sub-second part of the instant, use toDateTime() and DateTime.withMillisOfSecond(int).

        Parameters:
        newMillis - the new millis, from 1970-01-01T00:00:00Z
        Returns:
        a copy of this instant with different millis

      • withDurationAdded

        public Instant withDurationAdded​(long durationToAdd,
                                 int scalar)
        Gets a copy of this instant with the specified duration added.

        If the addition is zero, then this is returned.

        Parameters:
        durationToAdd - the duration to add to this one
        scalar - the amount of times to add, such as -1 to subtract once
        Returns:
        a copy of this instant with the duration added
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • withDurationAdded

        public Instant withDurationAdded​(ReadableDuration durationToAdd,
                                 int scalar)
        Gets a copy of this instant with the specified duration added.

        If the addition is zero, then this is returned.

        Parameters:
        durationToAdd - the duration to add to this one, null means zero
        scalar - the amount of times to add, such as -1 to subtract once
        Returns:
        a copy of this instant with the duration added
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • plus

        public Instant plus​(long duration)
        Gets a copy of this instant with the specified duration added.

        If the amount is zero or null, then this is returned.

        Parameters:
        duration - the duration to add to this one
        Returns:
        a copy of this instant with the duration added
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • plus

        public Instant plus​(ReadableDuration duration)
        Gets a copy of this instant with the specified duration added.

        If the amount is zero or null, then this is returned.

        Parameters:
        duration - the duration to add to this one, null means zero
        Returns:
        a copy of this instant with the duration added
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • minus

        public Instant minus​(long duration)
        Gets a copy of this instant with the specified duration taken away.

        If the amount is zero or null, then this is returned.

        Parameters:
        duration - the duration to reduce this instant by
        Returns:
        a copy of this instant with the duration taken away
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • minus

        public Instant minus​(ReadableDuration duration)
        Gets a copy of this instant with the specified duration taken away.

        If the amount is zero or null, then this is returned.

        Parameters:
        duration - the duration to reduce this instant by
        Returns:
        a copy of this instant with the duration taken away
        Throws:
        java.lang.ArithmeticException - if the new instant exceeds the capacity of a long

      • getMillis

        public long getMillis()
        Gets the milliseconds of the instant.
        Specified by:
        getMillis in interface ReadableInstant
        Returns:
        the number of milliseconds since 1970-01-01T00:00:00Z

      • toDateTime

        public DateTime toDateTime()
        Get this object as a DateTime using ISOChronology in the default zone.

        This method returns a DateTime object in the default zone. This differs from the similarly named method on DateTime, DateMidnight or MutableDateTime which retains the time zone. The difference is because Instant really represents a time without a zone, thus calling this method we really have no zone to 'retain' and hence expect to switch to the default zone.

        This method definition preserves compatibility with earlier versions of Joda-Time.

        Overrides:
        toDateTime in class AbstractInstant
        Returns:
        a DateTime using the same millis

      • toDateTimeISO

        @Deprecated
public DateTime toDateTimeISO()
        Deprecated.
        Use toDateTime() as it is identical
        Get this object as a DateTime using ISOChronology in the default zone. This method is identical to toDateTime().

        This method returns a DateTime object in the default zone. This differs from the similarly named method on DateTime, DateMidnight or MutableDateTime which retains the time zone. The difference is because Instant really represents a time without a zone, thus calling this method we really have no zone to 'retain' and hence expect to switch to the default zone.

        This method is deprecated because it is a duplicate of toDateTime(). However, removing it would cause the superclass implementation to be used, which would create silent bugs in any caller depending on this implementation. As such, the method itself is not currently planned to be removed.

        This method definition preserves compatibility with earlier versions of Joda-Time.

        Overrides:
        toDateTimeISO in class AbstractInstant
        Returns:
        a DateTime using the same millis with ISOChronology

      • toMutableDateTime

        public MutableDateTime toMutableDateTime()
        Get this object as a MutableDateTime using ISOChronology in the default zone.

        This method returns a MutableDateTime object in the default zone. This differs from the similarly named method on DateTime, DateMidnight or MutableDateTime which retains the time zone. The difference is because Instant really represents a time without a zone, thus calling this method we really have no zone to 'retain' and hence expect to switch to the default zone.

        This method definition preserves compatibility with earlier versions of Joda-Time.

        Overrides:
        toMutableDateTime in class AbstractInstant
        Returns:
        a MutableDateTime using the same millis

      • toMutableDateTimeISO

        @Deprecated
public MutableDateTime toMutableDateTimeISO()
        Deprecated.
        Use toMutableDateTime() as it is identical
        Get this object as a MutableDateTime using ISOChronology in the default zone. This method is identical to toMutableDateTime().

        This method returns a MutableDateTime object in the default zone. This differs from the similarly named method on DateTime, DateMidnight or MutableDateTime which retains the time zone. The difference is because Instant really represents a time without a zone, thus calling this method we really have no zone to 'retain' and hence expect to switch to the default zone.

        This method is deprecated because it is a duplicate of toMutableDateTime(). However, removing it would cause the superclass implementation to be used, which would create silent bugs in any caller depending on this implementation. As such, the method itself is not currently planned to be removed.

        This method definition preserves compatibility with earlier versions of Joda-Time.

        Overrides:
        toMutableDateTimeISO in class AbstractInstant
        Returns:
        a MutableDateTime using the same millis with ISOChronology