org.threadly.concurrent

Class SchedulingUtils

java.lang.Object

org.threadly.concurrent.SchedulingUtils

public class SchedulingUtils
extends java.lang.Object

Class for helping calculate the offset for scheduling tasks. For example if you want a task to run at 10 minutes after the hour, every hour, you can use getDelayTillMinute(int) to calculate the initial delay needed when scheduling with SubmitterScheduler.scheduleAtFixedRate(Runnable, long, long), and then provide 1 hour in milliseconds for the "period".

Since:

3.5.0

Constructor Summary

Constructors

Constructor and Description
SchedulingUtils()

Method Summary

Modifier and Type	Method and Description
static long	getDelayTillHour(int hour, int minute) Call to calculate how many milliseconds until the provided time.
static long	getDelayTillMinute(int minute) Call to calculate how many milliseconds until the provided minute.
static int	shiftLocalHourToUTC(int hour) This will shift an hour from the local time zone to UTC.

Methods inherited from class java.lang.Object

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

Constructor Detail

SchedulingUtils

public SchedulingUtils()

Method Detail

getDelayTillMinute

public static long getDelayTillMinute(int minute)

Call to calculate how many milliseconds until the provided minute. If we are past the provided minute, it will be the milliseconds until we reach that minute with the NEXT hour.

Because of use of Clock.lastKnownTimeMillis(), this calculation will only be accurate within about 100 milliseconds. Of course if provided to a scheduler, depending on it's work load that variation may be greater.

Parameters:

minute - Minute to calculate too, can not be negative and must be less than 60

Returns:

Time in milliseconds till that minute is reached

getDelayTillHour

public static long getDelayTillHour(int hour,
                                    int minute)

Call to calculate how many milliseconds until the provided time. If we are past the provided hour/minute, it will be the milliseconds until we reach that time with the NEXT day.

It is important to note that the time zone for this hour is UTC. If you want to use this for local time, just pass the hour through shiftLocalHourToUTC(int). This will convert a local time's hour to UTC so that it can be used in this invocation.

Because of use of Clock.lastKnownTimeMillis(), this calculation will only be accurate within about 100 milliseconds. Of course if provided to a scheduler, depending on it's work load that variation may be greater.

Parameters:

hour - Hour in the 24 hour format, can not be negative and must be less than 24

minute - Minute to calculate too, can not be negative and must be less than 60

Returns:

Time in milliseconds till provided time is reached

shiftLocalHourToUTC

public static int shiftLocalHourToUTC(int hour)

This will shift an hour from the local time zone to UTC. This shift will take into account the current local state of daylight savings time. The primary usage of this is so that getDelayTillHour(int, int) can be used with a local time zone hour.

Parameters:

hour - Hour to be shifted in the local time zone in 24 hour format

Returns:

Hour shifted to the UTC time zone in 24 hour format