org.apache.commons.compress.utils

Class TimeUtils

java.lang.Object

org.apache.commons.compress.utils.TimeUtils

public final class TimeUtils
extends Object

Utility class for handling time-related types and conversions.

Understanding Unix vs NTFS timestamps:

• A Unix timestamp is a primitive long starting at the Unix Epoch on January 1st, 1970 at Coordinated Universal Time (UTC)
• An NTFS timestamp is a file time is a 64-bit value that represents the number of 100-nanosecond intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated Universal Time (UTC).

Since:

1.23

Method Summary

Modifier and Type	Method and Description
static boolean	isUnixTime(FileTime time) Tests whether a FileTime can be safely represented in the standard UNIX time.
static boolean	isUnixTime(long seconds) Tests whether a given number of seconds (since Epoch) can be safely represented in the standard UNIX time.
static Date	ntfsTimeToDate(long ntfsTime) Converts NTFS time (100 nanosecond units since 1 January 1601) to Java time.
static FileTime	ntfsTimeToFileTime(long ntfsTime) Converts NTFS time (100-nanosecond units since 1 January 1601) to a FileTime.
static Date	toDate(FileTime fileTime) Converts FileTime to a Date.
static FileTime	toFileTime(Date date) Converts Date to a FileTime.
static long	toNtfsTime(Date date) Converts a Date to NTFS time.
static long	toNtfsTime(FileTime fileTime) Converts a FileTime to NTFS time (100-nanosecond units since 1 January 1601).
static long	toNtfsTime(long javaTime) Converts Java time (milliseconds since Epoch) to NTFS time.
static long	toUnixTime(FileTime fileTime) Converts FileTime to standard UNIX time.
static FileTime	truncateToHundredNanos(FileTime fileTime) Truncates a FileTime to 100-nanosecond precision.
static FileTime	unixTimeToFileTime(long time) Converts standard UNIX time (in seconds, UTC/GMT) to FileTime.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isUnixTime

public static boolean isUnixTime(FileTime time)

Tests whether a FileTime can be safely represented in the standard UNIX time.

TODO ? If the FileTime is null, this method always returns true.

Parameters:

time - the FileTime to evaluate, can be null

Returns:

true if the time exceeds the minimum or maximum UNIX time, false otherwise

isUnixTime

public static boolean isUnixTime(long seconds)

Tests whether a given number of seconds (since Epoch) can be safely represented in the standard UNIX time.

Parameters:

seconds - the number of seconds (since Epoch) to evaluate

Returns:

true if the time can be represented in the standard UNIX time, false otherwise

ntfsTimeToDate

public static Date ntfsTimeToDate(long ntfsTime)

Converts NTFS time (100 nanosecond units since 1 January 1601) to Java time.

Parameters:

ntfsTime - the NTFS time in 100 nanosecond units

Returns:

the Date

ntfsTimeToFileTime

public static FileTime ntfsTimeToFileTime(long ntfsTime)

Converts NTFS time (100-nanosecond units since 1 January 1601) to a FileTime.

Parameters:

ntfsTime - the NTFS time in 100-nanosecond units

Returns:

the FileTime

See Also:

WINDOWS_EPOCH_OFFSET, toNtfsTime(FileTime)

toDate

public static Date toDate(FileTime fileTime)

Converts FileTime to a Date. If the provided FileTime is null, the returned Date is also null.

Parameters:

fileTime - the file time to be converted.

Returns:

a Date which corresponds to the supplied time, or null if the time is null.

See Also:

toFileTime(Date)

toFileTime

public static FileTime toFileTime(Date date)

Converts Date to a FileTime. If the provided Date is null, the returned FileTime is also null.

Parameters:

date - the date to be converted.

Returns:

a FileTime which corresponds to the supplied date, or null if the date is null.

See Also:

toDate(FileTime)

toNtfsTime

public static long toNtfsTime(Date date)

Converts a Date to NTFS time.

Parameters:

date - the Date

Returns:

the NTFS time

toNtfsTime

public static long toNtfsTime(FileTime fileTime)

Converts a FileTime to NTFS time (100-nanosecond units since 1 January 1601).

Parameters:

fileTime - the FileTime

Returns:

the NTFS time in 100-nanosecond units

See Also:

WINDOWS_EPOCH_OFFSET, ntfsTimeToFileTime(long)

toNtfsTime

public static long toNtfsTime(long javaTime)

Converts Java time (milliseconds since Epoch) to NTFS time.

Parameters:

javaTime - the Java time

Returns:

the NTFS time

toUnixTime

public static long toUnixTime(FileTime fileTime)

Converts FileTime to standard UNIX time.

Parameters:

fileTime - the original FileTime

Returns:

the UNIX timestamp

truncateToHundredNanos

public static FileTime truncateToHundredNanos(FileTime fileTime)

Truncates a FileTime to 100-nanosecond precision.

Parameters:

fileTime - the FileTime to be truncated

Returns:

the truncated FileTime

unixTimeToFileTime

public static FileTime unixTimeToFileTime(long time)

Converts standard UNIX time (in seconds, UTC/GMT) to FileTime.

Parameters:

time - UNIX timestamp

Returns:

the corresponding FileTime