Module org.apache.wicket.util

Package org.apache.wicket.util.thread

Class Task

java.lang.Object

org.apache.wicket.util.thread.Task

public final class Task
extends Object

Runs a block of code periodically. A Task can be started at a given time in the future and can be a daemon. The block of code will be passed a Log object each time it is run through its ICode interface.

If the code block takes longer than the period to run, the next task invocation will occur immediately. In this case, tasks will not occur at precise multiples of the period. For example, if you run a task every 30 seconds, and the first run takes 40 seconds but the second takes 20 seconds, your task will be invoked at 0 seconds, 40 seconds and 70 seconds (40 seconds + 30 seconds), which is not an even multiple of 30 seconds.

In general, this is a simple task class designed for polling activities. If you need precise guarantees, you probably should be using a different task class.

Since:

1.2.6

Author:

Jonathan Locke

Constructor Summary

Constructors

Constructor	Description
Task(String name)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected org.slf4j.Logger	getLog()	Gets the log for this Task.
int	getPriority()	Gets the thread priority
void	interrupt()	Interrupts the Task as soon as it has the opportunity.
final void	run(Duration frequency, ICode code)	Runs this Task at the given frequency.
void	setDaemon(boolean daemon)	Sets daemon or not.
void	setLog(org.slf4j.Logger log)	Sets log for user code to log to when task runs.
void	setPriority(int prio)	Sets the priority of the thread
void	setStartTime(Instant startTime)	Sets start time for this task.
void	stop()	Stops this Task as soon as it has the opportunity.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

Task

public Task(String name)

Constructor.

Parameters:

name - the name of this Task

Method Details

run

public final void run(Duration frequency,
 ICode code)

Runs this Task at the given frequency. You may only call this method if the task has not yet been started. If the task is already running, an IllegalStateException will be thrown.

Parameters:

frequency - the frequency at which to run the code

code - the code to run

Throws:

IllegalStateException - thrown if task is already running

setDaemon

public void setDaemon(boolean daemon)

Sets daemon or not. For obvious reasons, this value can only be set before the task starts running. If you attempt to set this value after the task starts running, an IllegalStateException will be thrown.

Parameters:

daemon - true if this Task's Thread should be a daemon

Throws:

IllegalStateException - thrown if task is already running

setLog

public void setLog(org.slf4j.Logger log)

Sets log for user code to log to when task runs.

Parameters:

log - the log

setStartTime

public void setStartTime(Instant startTime)

Sets start time for this task. You cannot set the start time for a task which is already running. If you attempt to, an IllegalStateException will be thrown.

Parameters:

startTime - The time this task should start running

Throws:

IllegalStateException - Thrown if task is already running

toString

public String toString()

Overrides:

toString in class Object

See Also:

• Object.toString()

getLog

protected org.slf4j.Logger getLog()

Gets the log for this Task.

Returns:

the log

stop

public void stop()

Stops this Task as soon as it has the opportunity.

interrupt

public void interrupt()

Interrupts the Task as soon as it has the opportunity.

setPriority

public void setPriority(int prio)

Sets the priority of the thread

Parameters:

prio -

getPriority

public int getPriority()

Gets the thread priority

Returns:

priority