Module java.base
Package java.nio.file.attribute

Class FileTime

java.lang.Object
java.nio.file.attribute.FileTime
All Implemented Interfaces:
Comparable<FileTime>
public final class FileTime extends Object implements Comparable<FileTime>
Represents the value of a file's time stamp attribute. For example, it may represent the time that the file was last modified, accessed, or created.

Instances of this class are immutable.

Since:
1.7
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    compareTo(FileTime other)
    Compares the value of two FileTime objects for order.
    boolean
    equals(Object obj)
    Tests this FileTime for equality with the given object.
    static FileTime
    from(long value, TimeUnit unit)
    Returns a FileTime representing a value at the given unit of granularity.
    static FileTime
    from(Instant instant)
    Returns a FileTime representing the same point of time value on the time-line as the provided Instant object.
    static FileTime
    fromMillis(long value)
    Returns a FileTime representing the given value in milliseconds.
    int
    hashCode()
    Computes a hash code for this file time.
    long
    to(TimeUnit unit)
    Returns the value at the given unit of granularity.
    Instant
    toInstant()
    Converts this FileTime object to an Instant.
    long
    toMillis()
    Returns the value in milliseconds.
    String
    toString()
    Returns the string representation of this FileTime.

    Methods declared in class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Method Details

    • from

      public static FileTime from(long value, TimeUnit unit)
      Returns a FileTime representing a value at the given unit of granularity.
      Parameters:
      value - the value since the epoch (1970-01-01T00:00:00Z); can be negative
      unit - the unit of granularity to interpret the value
      Returns:
      a FileTime representing the given value

    • fromMillis

      public static FileTime fromMillis(long value)
      Returns a FileTime representing the given value in milliseconds.
      Parameters:
      value - the value, in milliseconds, since the epoch (1970-01-01T00:00:00Z); can be negative
      Returns:
      a FileTime representing the given value

    • from

      public static FileTime from(Instant instant)
      Returns a FileTime representing the same point of time value on the time-line as the provided Instant object.
      Parameters:
      instant - the instant to convert
      Returns:
      a FileTime representing the same point on the time-line as the provided instant
      Since:
      1.8

    • to

      public long to(TimeUnit unit)
      Returns the value at the given unit of granularity.

      Conversion from a coarser granularity that would numerically overflow saturate to Long.MIN_VALUE if negative or Long.MAX_VALUE if positive.

      Parameters:
      unit - the unit of granularity for the return value
      Returns:
      value in the given unit of granularity, since the epoch since the epoch (1970-01-01T00:00:00Z); can be negative

    • toMillis

      public long toMillis()
      Returns the value in milliseconds.

      Conversion from a coarser granularity that would numerically overflow saturate to Long.MIN_VALUE if negative or Long.MAX_VALUE if positive.

      Returns:
      the value in milliseconds, since the epoch (1970-01-01T00:00:00Z)

    • toInstant

      public Instant toInstant()
      Converts this FileTime object to an Instant.

      The conversion creates an Instant that represents the same point on the time-line as this FileTime.

      FileTime can store points on the time-line further in the future and further in the past than Instant. Conversion from such further time points saturates to Instant.MIN if earlier than Instant.MIN or Instant.MAX if later than Instant.MAX.

      Returns:
      an instant representing the same point on the time-line as this FileTime object
      Since:
      1.8

    • equals

      public boolean equals(Object obj)
      Tests this FileTime for equality with the given object.

      The result is true if and only if the argument is not null and is a FileTime that represents the same time. This method satisfies the general contract of the Object.equals method.

      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare with
      Returns:
      true if, and only if, the given object is a FileTime that represents the same time
      See Also:

    • hashCode

      public int hashCode()
      Computes a hash code for this file time.

      The hash code is based upon the value represented, and satisfies the general contract of the Object.hashCode() method.

      Overrides:
      hashCode in class Object
      Returns:
      the hash-code value
      See Also:

    • compareTo

      public int compareTo(FileTime other)
      Compares the value of two FileTime objects for order.
      Specified by:
      compareTo in interface Comparable<FileTime>
      Parameters:
      other - the other FileTime to be compared
      Returns:
      0 if this FileTime is equal to other, a value less than 0 if this FileTime represents a time that is before other, and a value greater than 0 if this FileTime represents a time that is after other

    • toString

      public String toString()
      Returns the string representation of this FileTime. The string is returned in the ISO 8601 format: 
           YYYY-MM-DDThh:mm:ss[.s+]Z
      where "[.s+]" represents a dot followed by one of more digits for the decimal fraction of a second. It is only present when the decimal fraction of a second is not zero. For example, FileTime.fromMillis(1234567890000L).toString() yields "2009-02-13T23:31:30Z", and FileTime.fromMillis(1234567890123L).toString() yields "2009-02-13T23:31:30.123Z".

      A FileTime is primarily intended to represent the value of a file's time stamp. Where used to represent extreme values, where the year is less than "0001" or greater than "9999" then this method deviates from ISO 8601 in the same manner as the XML Schema language. That is, the year may be expanded to more than four digits and may be negative-signed. If more than four digits then leading zeros are not present. The year before "0001" is "-0001".

      Overrides:
      toString in class Object
      Returns:
      the string representation of this file time