edu.luc.cs.trull.task
Class DefaultTaskWorker

java.lang.Object
  edu.luc.cs.trull.EmptyComponent
      edu.luc.cs.trull.TerminatingComponent
          edu.luc.cs.trull.task.DefaultTaskWorker

All Implemented Interfaces:

Component, PropertyChangeSource, Startable, Suspendable, Terminating, java.beans.PropertyChangeListener, java.util.EventListener

public class DefaultTaskWorker
extends TerminatingComponent

A Worker for the step-by-step execution of a Task using Trull's default scheduling mechanism. If this Worker does not provide sufficient responsiveness, consider making the task finer-grained or using a Worker implementation that carries out the task in one or more separate threads.

See Also:

Task, QueuedTaskWorker, PooledTaskWorker

Field Summary

protected boolean	firstTime A flag indicating whether the task is being executed for the first time.
private static org.apache.log4j.Logger	logger
protected java.lang.Runnable	repeat A Runnable that executes one step of the task and reschedules itself for execution as long as the worker has not been suspended.
protected static int	RUNNING The running state.
protected int	state The variable holding the current state.
protected static int	STOPPED The stopped state.
protected static int	SUSPENDED The suspended state.
protected Task	task The task executed by this worker.

Constructor Summary

DefaultTaskWorker(Task task)
Constructs a worker for the given task.

Method Summary

void	resume() Resumes this suspendable component.
void	setTask(Task task) Sets the task to be performed.
void	start(java.beans.PropertyChangeEvent incoming) Restarts the task if necessary and schedules the repeat Runnable for executing the task step-by-step.
void	stop() Stops this startable component.
void	suspend() Suspends this suspendable component.

Methods inherited from class edu.luc.cs.trull.TerminatingComponent

fireTermination, getParent, getTermEvent, scheduleTermination, setTerminationListener

Methods inherited from class edu.luc.cs.trull.EmptyComponent

addPropertyChangeListener, getPropertyChangeListeners, getTerminationListener, propertyChange, removePropertyChangeListener

Methods inherited from class java.lang.Object

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

Field Detail

firstTime

protected boolean firstTime

A flag indicating whether the task is being executed for the first time.

logger

private static org.apache.log4j.Logger logger

repeat

protected final java.lang.Runnable repeat

A Runnable that executes one step of the task and reschedules itself for execution as long as the worker has not been suspended.

RUNNING

protected static final int RUNNING

The running state.

See Also:

Constant Field Values

state

protected int state

The variable holding the current state.

STOPPED

protected static final int STOPPED

The stopped state.

See Also:

Constant Field Values

SUSPENDED

protected static final int SUSPENDED

The suspended state.

See Also:

Constant Field Values

task

protected Task task

The task executed by this worker.

Constructor Detail

DefaultTaskWorker

public DefaultTaskWorker(Task task)

Constructs a worker for the given task.

Parameters:

task - the task to be performed.

Throws:

java.lang.IllegalArgumentException - if the task is null.

Method Detail

resume

public void resume()

Description copied from interface: Suspendable

Resumes this suspendable component.

Specified by:

resume in interface Suspendable

Overrides:

resume in class EmptyComponent

setTask

public void setTask(Task task)

Sets the task to be performed.

Parameters:

task - the task to be performed.

Throws:

java.lang.IllegalArgumentException - if the task is null.

start

public void start(java.beans.PropertyChangeEvent incoming)

Restarts the task if necessary and schedules the repeat Runnable for executing the task step-by-step.

Specified by:

start in interface Startable

Overrides:

start in class EmptyComponent

Parameters:

incoming - the event that triggered the invocation of this method. May be null.

stop

public void stop()

Description copied from interface: Startable

Stops this startable component.

Specified by:

stop in interface Startable

Overrides:

stop in class EmptyComponent

suspend

public void suspend()

Description copied from interface: Suspendable

Suspends this suspendable component.

Specified by:

suspend in interface Suspendable

Overrides:

suspend in class EmptyComponent