Task
Class AbstractTask

java.lang.Object
  Task.AbstractTask

Direct Known Subclasses:

NetworkTask, SimpleTask

public abstract class AbstractTask
extends java.lang.Object

AbstractTask is a super class that encapsulates some common functionality between various types of tasks:

1. SimpleTask
2. NetworkTask
3. RecurringNetworkTask

Since:

Jun 29, 2007, 1:10:10 PM

Version:

1.0

Author:

Nazmul Idris

Nested Class Summary

static class	AbstractTask.PropertyNames enumeration that holds list of properties that you can attach property change listeners for, right now there's only one, but you can add more in the future.
static class	AbstractTask.State List of all the possible states that any kind of Task (Network, non network, etc) may have.
static class	AbstractTask.Type identifies the type of the task

Field Summary

protected AutoShutdownSignals[]	_autoShutdownRay this holds all the AutoShutdownSignals types that this task will respond to
protected java.beans.PropertyChangeSupport	_boundProperties
protected java.util.concurrent.locks.Lock	_boundPropertiesLock
protected boolean	_shutdownCalled
protected AbstractTask.State	_state
protected java.lang.String	_status
protected TaskManager	_taskManager

Constructor Summary

AbstractTask()

Method Summary

protected void	_assertIsNotShutdown() makes sure that shutdown() has not been called yet.
protected void	_assertNoSwingWorkerCurrentlyActive() makes sure that an existing SwingWorker is not already in flight. also if cleared for execution (SwingWorker creation).
void	addStatusListener(java.beans.PropertyChangeListener l) PropertyChangeEvent.getNewValue() contains the status message.
void	cancel() This method causes the cancel() method to be called on the underlying SwingWorker object (and thread).
void	clearAllStatusListeners()
abstract 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
abstract void	execute()
java.lang.String	formattedString()
AutoShutdownSignals[]	getAutoShutdownPolicy()
protected java.beans.PropertyChangeSupport	getBoundProperties()
java.lang.String	getDescription()
java.lang.String	getName()
java.lang.Object	getState()
java.lang.String	getStatus()
abstract javax.swing.SwingWorker	getSwingWorker()
protected TaskManager	getTaskManager()
abstract AbstractTask.Type	getType()
SwingUIHookAdapter	getUIHook()
boolean	hasAutoShutdownPolicy(AutoShutdownSignals policy) returns true if this task has an autostop policy that matches the param
boolean	isShutdown()
void	setAutoShutdownPolicy(AutoShutdownSignals... policy)
void	setDescription(java.lang.String descr)
void	setName(java.lang.String name)
void	setState(AbstractTask.State stateValue)
void	setStatus(java.lang.String s)
protected void	setTaskManager(TaskManager container)
void	shutdown()

Methods inherited from class java.lang.Object

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

Field Detail

_autoShutdownRay

protected AutoShutdownSignals[] _autoShutdownRay

this holds all the AutoShutdownSignals types that this task will respond to

_shutdownCalled

protected boolean _shutdownCalled

_taskManager

protected TaskManager _taskManager

_boundPropertiesLock

protected java.util.concurrent.locks.Lock _boundPropertiesLock

_boundProperties

protected java.beans.PropertyChangeSupport _boundProperties

_status

protected java.lang.String _status

_state

protected AbstractTask.State _state

Constructor Detail

AbstractTask

public AbstractTask()

Method Detail

getType

public abstract AbstractTask.Type getType()

getUIHook

public SwingUIHookAdapter getUIHook()

getAutoShutdownPolicy

public AutoShutdownSignals[] getAutoShutdownPolicy()

setAutoShutdownPolicy

public void setAutoShutdownPolicy(AutoShutdownSignals... policy)

isShutdown

public boolean isShutdown()

shutdown

public void shutdown()

hasAutoShutdownPolicy

public boolean hasAutoShutdownPolicy(AutoShutdownSignals policy)
                              throws java.lang.IllegalArgumentException

returns true if this task has an autostop policy that matches the param

Throws:

java.lang.IllegalArgumentException

doShutdown

public abstract 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

getTaskManager

protected TaskManager getTaskManager()

setTaskManager

protected void setTaskManager(TaskManager container)

getStatus

public java.lang.String getStatus()

getState

public java.lang.Object getState()

getBoundProperties

protected java.beans.PropertyChangeSupport getBoundProperties()

setStatus

public void setStatus(java.lang.String s)

setState

public void setState(AbstractTask.State stateValue)

addStatusListener

public void addStatusListener(java.beans.PropertyChangeListener l)

PropertyChangeEvent.getNewValue() contains the status message. Here's an example:

 public void propertyChange(PropertyChangeEvent evt) {
   _setStatus(evt.getNewValue().toString());
 }
 

clearAllStatusListeners

public void clearAllStatusListeners()

getSwingWorker

public abstract javax.swing.SwingWorker getSwingWorker()

execute

public abstract void execute()
                      throws TaskException

Throws:

TaskException

cancel

public void cancel()

This method causes the cancel() method to be called on the underlying SwingWorker object (and thread). The implementation of the TaskExecutorIF needs to check SwingWorker.isCancelled() in order for this to work. The InterruptedException will be thrown when this method is called, if need be.

_assertNoSwingWorkerCurrentlyActive

protected void _assertNoSwingWorkerCurrentlyActive()
                                            throws TaskException

makes sure that an existing SwingWorker is not already in flight. also if cleared for execution (SwingWorker creation).

the cancel flag is cleared on the SwingUIHookAdapter.resetCancelFlag(). if a task was cancelled previously, then that cancellation is not longer active, since the getUIHook() is about to be bound to a new execution environment (thread/swingworker).

Throws:

TaskException - TaskException.Type.ExecutionAttemptAfterTaskIsShutdown

_assertIsNotShutdown

protected void _assertIsNotShutdown()
                             throws TaskException

makes sure that shutdown() has not been called yet.

Throws:

TaskException - TaskException.Type.ExecutionAttemptAfterTaskIsShutdown

getName

public java.lang.String getName()

getDescription

public java.lang.String getDescription()

setName

public void setName(java.lang.String name)

setDescription

public void setDescription(java.lang.String descr)

formattedString

public java.lang.String formattedString()