Task
Class RecurringNetworkTask<ReturnValueType>

java.lang.Object
  Task.AbstractTask
      Task.NetworkTask<ReturnValueType>
          Task.RecurringNetworkTask<ReturnValueType>

public class RecurringNetworkTask<ReturnValueType>
extends NetworkTask<ReturnValueType>

This task is a subclass of NetworkTask. It adds the abillty to perform recurring tasks on top of the implementation of NetworkTask.

You can specify a refresh delay to define the schedule that will be used to run the TaskExecutor. You can change this at any time as well.

Since:

May 30, 2007, 1:33:23 PM

Version:

1.0

Author:

Nazmul Idris

Nested Class Summary

Nested classes/interfaces inherited from class Task.AbstractTask

AbstractTask.PropertyNames, AbstractTask.State, AbstractTask.Type

Field Summary

protected java.util.concurrent.ScheduledExecutorService	_execService
protected int	_refreshDelayInSec
protected java.util.concurrent.ScheduledFuture	_scheduledFuture

Fields inherited from class Task.NetworkTask

_exec, _swingWorker, _taskHandler, testMode_Enabled, testMode_isOnline

Fields inherited from class Task.AbstractTask

_autoShutdownRay, _boundProperties, _boundPropertiesLock, _shutdownCalled, _state, _status, _taskManager

Constructor Summary

RecurringNetworkTask(TaskExecutorIF<ReturnValueType> exec)

RecurringNetworkTask(TaskManager container, TaskExecutorIF<ReturnValueType> exec, java.lang.String name, java.lang.String descr, AutoShutdownSignals... policy)

Method Summary

protected void	_cancelScheduledFuture() This will cancel any Runnables that are being scheduled by the executor service.
protected void	_initScheduledFuture() This method actually attaches a Runnable object + delay with the _execService.
void	doShutdown() subclass should implement this method as is appropriate for them. this is called when the task is stopped, based on the AutoShutdownSignals policy
AbstractTask.Type	getType()
void	restartWithNewDelay(int refreshDelayInSec) After start(int) is called, this method can be used to change the refreshDelayInSec ...
void	setRefreshDelay(int refreshDelayInSec) Set the time delay between running TaskExecutorIF continually.
void	start() Start the recurring network task... it will use the default refresh delay...
void	start(int refreshDelayInSec) Start the recurring network task... it will periodically run the TaskExecutorIF in the background.
void	stopRecurring() Stop the recurring network task... this will stop the network task from running TaskExecutorIF in the background.

Methods inherited from class Task.NetworkTask

_createSwingWorker, _openGate, execute, executeAndWait, getSwingWorker, setTaskHandler, setTestMode_isOnline

Methods inherited from class Task.AbstractTask

_assertIsNotShutdown, _assertNoSwingWorkerCurrentlyActive, addStatusListener, cancel, clearAllStatusListeners, formattedString, getAutoShutdownPolicy, getBoundProperties, getDescription, getName, getState, getStatus, getTaskManager, getUIHook, hasAutoShutdownPolicy, isShutdown, setAutoShutdownPolicy, setDescription, setName, setState, setStatus, setTaskManager, shutdown

Methods inherited from class java.lang.Object

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

Field Detail

_refreshDelayInSec

protected int _refreshDelayInSec

_execService

protected java.util.concurrent.ScheduledExecutorService _execService

_scheduledFuture

protected java.util.concurrent.ScheduledFuture _scheduledFuture

Constructor Detail

RecurringNetworkTask

public RecurringNetworkTask(TaskManager container,
                            TaskExecutorIF<ReturnValueType> exec,
                            java.lang.String name,
                            java.lang.String descr,
                            AutoShutdownSignals... policy)
                     throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

RecurringNetworkTask

public RecurringNetworkTask(TaskExecutorIF<ReturnValueType> exec)

Method Detail

getType

public AbstractTask.Type getType()

Overrides:

getType in class NetworkTask<ReturnValueType>

doShutdown

public void doShutdown()

subclass should implement this method as is appropriate for them. this is called when the task is stopped, based on the AutoShutdownSignals policy

Overrides:

doShutdown in class NetworkTask<ReturnValueType>

start

public void start(int refreshDelayInSec)
           throws TaskException

Start the recurring network task... it will periodically run the TaskExecutorIF in the background.

Throws:

TaskException

start

public void start()
           throws TaskException

Start the recurring network task... it will use the default refresh delay...

Throws:

TaskException

restartWithNewDelay

public void restartWithNewDelay(int refreshDelayInSec)
                         throws TaskException

After start(int) is called, this method can be used to change the refreshDelayInSec ...

Throws:

TaskException

_initScheduledFuture

protected void _initScheduledFuture()
                             throws TaskException

This method actually attaches a Runnable object + delay with the _execService.

The way this scheduler works is that it creates a new task at a delay. As long as a task is running, it will not create another one. So, the NetworkTask.executeAndWait() method just creates a new SwingWorker, and then waits for it to complete. The reason not to use NetworkTask.execute() is simply to keep new tasks from getting created until the first one finishes. That's why there is a gate to block the currently executing Runnable below until the underlying SwingWorker is complete!

So really, the total delay between these SwingWorkers being spawned is: Time required by the SwingWorker to execute to completion (err, ok, interrupted) + delay

Throws:

TaskException

_cancelScheduledFuture

protected void _cancelScheduledFuture()

This will cancel any Runnables that are being scheduled by the executor service. Additionally, if any SwingWorkers are currently running, they are cancelled as well.

See Also:

AbstractTask.cancel(), NetworkTask.executeAndWait()

stopRecurring

public void stopRecurring()

Stop the recurring network task... this will stop the network task from running TaskExecutorIF in the background. Also, stop any currently executing tasks:

1. Thread: NetworkTask.getSwingWorker() - Method to kill it:AbstractTask.cancel()
2. Thread: _scheduledFuture - Method to kill it:_cancelScheduledFuture()

setRefreshDelay

public void setRefreshDelay(int refreshDelayInSec)

Set the time delay between running TaskExecutorIF continually.

Parameters:

refreshDelayInSec - the time delay is in TimeUnit.SECONDS