Class 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:
Files.setLastModifiedTime(java.nio.file.Path, java.nio.file.attribute.FileTime), Files.getLastModifiedTime(java.nio.file.Path, java.nio.file.LinkOption...)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
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 Detail

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:
Object.hashCode(), HashMap

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:
Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

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