io.timeandspace.cronscheduler

Class CronSchedulerBuilder

java.lang.Object

io.timeandspace.cronscheduler.CronSchedulerBuilder

public class CronSchedulerBuilder
extends Object

A builder for CronScheduler. Create one using CronScheduler.newBuilder method.

Method Summary

Modifier and Type	Method and Description
CronScheduler	build() Creates and returns a new CronScheduler using this builder.
CronSchedulerBuilder	setBackwardTimeShiftLogger(Consumer<String> logger) Sets the logger to log detected backward time shift events.
CronSchedulerBuilder	setThreadFactory(ThreadFactory factory) Sets the thread factory to be used to create the CronScheduler's thread.
CronSchedulerBuilder	setThreadName(String threadName) Sets the name for the CronScheduler's thread.
CronSchedulerBuilder	setThreadPriority(int priority) Sets the thread priority for the CronScheduler's thread.
CronSchedulerBuilder	setTimeProvider(Clock timeProvider) Sets the time provider to be used in CronScheduler(s) created with this builder.

Methods inherited from class java.lang.Object

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

Method Detail

setThreadPriority

public CronSchedulerBuilder setThreadPriority(int priority)

Sets the thread priority for the CronScheduler's thread. If specified, overwrites the priority set by the ThreadFactory if any is set via setThreadFactory(ThreadFactory). By default, a thread of normal priority is created.

Parameters:

priority - the priority for the CronScheduler's thread

Returns:

this builder back

Throws:

IllegalArgumentException - if the given priority is less than Thread.MIN_PRIORITY or greater than Thread.MAX_PRIORITY.

setThreadName

public CronSchedulerBuilder setThreadName(String threadName)

Sets the name for the CronScheduler's thread. If specified, overwrites the name set by the ThreadFactory if any is set via setThreadFactory(ThreadFactory). By default, a name like "cron-scheduler-N" is used, where N is a global sequence number.

Parameters:

threadName - the name for the CronScheduler's thread

Returns:

this builder back

Throws:

NullPointerException - if the given name is null

setThreadFactory

public CronSchedulerBuilder setThreadFactory(ThreadFactory factory)

Sets the thread factory to be used to create the CronScheduler's thread. The default thread factory creates daemon threads of normal priority, not tied to any ThreadGroup, with a name of the form "cron-scheduler-N" where N is a global sequence number. If setThreadName(java.lang.String) or setThreadPriority(int) are explicitly specified they overwrite the values set by the thread factory.

Parameters:

factory - the thread factory to be used to create the CronScheduler's thread.

Returns:

this builder back

Throws:

NullPointerException - if the given factory is null

setTimeProvider

public CronSchedulerBuilder setTimeProvider(Clock timeProvider)

Sets the time provider to be used in CronScheduler(s) created with this builder. By default, Clock.systemUTC() is used, which in turn delegates to currentTimeMillis. Note that the time zone embedded into the Clock is not used by CronScheduler. Time zone-sensitive methods such as scheduleAtRoundTimesInDay accept ZoneId as a parameter.

Parameters:

timeProvider - a Clock instance used to provide the instant time

Returns:

this builder back

Throws:

NullPointerException - if the given time provider is null

build

public CronScheduler build()

Creates and returns a new CronScheduler using this builder.

Returns:

a new CronScheduler using parameters configured in this builder

setBackwardTimeShiftLogger

public CronSchedulerBuilder setBackwardTimeShiftLogger(Consumer<String> logger)

Sets the logger to log detected backward time shift events. "Backward time shift" means that two calls A and B to Clock.instant() with a happens-before relation between them return instantA and instantB where instantA is later than instantB. This may be caused by NTP server-initiated adjustments of the system time on the machine, manual adjustments of the system time on the machine, or leap seconds. Note that local time zone offset changes (e. g. daylight saving time changes) don't cause such time shifts because they affect wall clock representation of the instant times, not the instant times themselves.

By default, a lambda equivalent to message -> System.err.println(message) is used.

Example usage: setBackwardTimeShiftLogger(LoggerFactory.getLogger(CronScheduler.class)::info).

Parameters:

logger - the logger to log backward time shift events detected by the CronScheduler.

Returns:

this builder back

Throws:

NullPointerException - if the given logger is null