com.devexperts.util

Class TimeUtil

java.lang.Object

com.devexperts.util.TimeUtil

public class TimeUtil
extends Object

A collection of static utility methods for manipulation of Java long time.

See Also:

System.currentTimeMillis()

Field Summary

Fields

Modifier and Type	Field and Description
static long	DAY Number of milliseconds in an day.
static long	HOUR Number of milliseconds in an hour.
static long	MINUTE Number of milliseconds in a minute.
static long	SECOND Number of milliseconds in a second.

Method Summary

Modifier and Type	Method and Description
static long	computeDailyTime(long currentTime, LocalTime localTime, ZoneId zoneId) Calculating the daily time relative to the current timestamp, taking into account the time zone.
static int	getMillisFromTime(long timeMillis) Returns correct number of milliseconds with proper handling negative values.
static int	getSecondsFromTime(long timeMillis) Returns correct number of seconds with proper handling negative values and overflows.
static TimeZone	getTimeZone(String tz) Gets the TimeZone for the given ID similar same as TimeZone.getTimeZone(String) but throwing IllegalArgumentException if the time-zone cannot be parsed.
static TimeZone	getTimeZoneGmt() Returns GMT time-zone.
static LocalTime	parseLocalTime(String localTime) Parse the string representing the local time in string format DateTimeFormatter.ISO_LOCAL_TIME.

Methods inherited from class java.lang.Object

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

Field Detail

SECOND

public static final long SECOND

Number of milliseconds in a second.

See Also:

Constant Field Values

MINUTE

public static final long MINUTE

Number of milliseconds in a minute.

See Also:

Constant Field Values

HOUR

public static final long HOUR

Number of milliseconds in an hour.

See Also:

Constant Field Values

DAY

public static final long DAY

Number of milliseconds in an day.

See Also:

Constant Field Values

Method Detail

getSecondsFromTime

public static int getSecondsFromTime(long timeMillis)

Returns correct number of seconds with proper handling negative values and overflows. Idea is that number of milliseconds shall be within [0..999] interval so that the following equation always holds getSecondsFromTime(timeMillis) * 1000L + getMillisFromTime(timeMillis) == timeMillis as as long the time in seconds fits into int.

See Also:

getMillisFromTime(long)

getMillisFromTime

public static int getMillisFromTime(long timeMillis)

Returns correct number of milliseconds with proper handling negative values. Idea is that number of milliseconds shall be within [0..999] interval so that the following equation always holds getSecondsFromTime(timeMillis) * 1000L + getMillisFromTime(timeMillis) == timeMillis as as long the time in seconds fits into int.

See Also:

getSecondsFromTime(long)

getTimeZoneGmt

public static TimeZone getTimeZoneGmt()

Returns GMT time-zone.

Returns:

GMT time-zone.

getTimeZone

public static TimeZone getTimeZone(String tz)

Gets the TimeZone for the given ID similar same as TimeZone.getTimeZone(String) but throwing IllegalArgumentException if the time-zone cannot be parsed. Also note that shortened custom IDs are not allowed, e.g. "GMT-8:00" instead of "GMT-08:00" would throw an exception.

Parameters:

tz - the ID for a TimeZone, either an abbreviation such as "PST", a full name such as "America/Los_Angeles", or a custom ID such as "GMT-08:00". Note that the support of abbreviations is for compatibility only and full names should be used.

Returns:

the specified TimeZone.

Throws:

IllegalArgumentException - if the given ID cannot be understood.

computeDailyTime

public static long computeDailyTime(long currentTime,
                                    LocalTime localTime,
                                    ZoneId zoneId)

Calculating the daily time relative to the current timestamp, taking into account the time zone. If the current time is less than localTime result will be localTime in current day. If the current time is more or equal than localTime result will be localTime in the next day in that time. All results are calculated for the zoneId time zone.

We have two special cases of season time shifting:

• Transition day from summer to winter contains additional hour but result is predictable and will correspond with time in that timezone.
• Transition day from winter to summer has less than 24 hours per day and if localTime points to nonexistent time the nearest exist time in future will be chosen

Parameters:

currentTime - current epoch millis

localTime - desired daily time in LocalTime format

zoneId - time zone for calculating daily time

Returns:

the next daily time for the specified timezone in unix format in ms

parseLocalTime

public static LocalTime parseLocalTime(String localTime)

Parse the string representing the local time in string format DateTimeFormatter.ISO_LOCAL_TIME. A null or empty string interpreted as null.

Parameters:

localTime - in string format.

Returns:

LocalTime or null

Throws:

DateTimeParseException - if the text cannot be parsed