oracle.ifs.share

Class Task

java.lang.Object

oracle.ifs.share.Task

Direct Known Subclasses:

ClonedLibrarySessionManager.IncreasePoolTask, ClonedLibrarySessionManager.RequestSessionCreationTask, ClonedLibrarySessionManager.RequestShutdownTask, ClonedLibrarySessionManager.ReserveSessionTask, ClonedLibrarySessionManager.SessionCreationAcknowledgementTask, ClonedLibrarySessionManager.UnreserveSessionTask, TimerTask

public abstract class Task
extends Object

Represents a unit of execution to be performed by an Executor.

Author:

Dave Long

Constructor Summary

Constructors

Constructor and Description
Task()

Method Summary

Modifier and Type	Method and Description
abstract Object	call() Compute the value to be returned by the get method.
protected void	complete(Object returnValue, Throwable error) Notification by the ExecutionService that the call is complete.
void	finish() Allow event dispatching thread to complete the task after the call method has returned.
Object	get() Return the value created by the call method.
protected Executor	getDefaultExecutor() Get default executor for this task.
protected Executor	getExecutor() Get current active executor for this task.
Throwable	getThrowable() Return the value created by the call method.
protected long	getTimeoutPeriod() Get the timeout period for this task.
boolean	isDone() Return true if call has completed.
boolean	isFailed() Return true if call failed.
protected void	markCompleted(Object returnValue, Throwable error) mark this task as completed.
void	start() Submit the task for execution.
void	start(Executor executor) Submit the task for execution on the specified Executor.
void	timeout() Allow timeout to be performed.

Methods inherited from class java.lang.Object

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

Constructor Detail

Task

public Task()

Method Detail

start

public void start()

Submit the task for execution.

start

public void start(Executor executor)

Submit the task for execution on the specified Executor.

Parameters:

executor - the Executor on which to submit the task

getDefaultExecutor

protected Executor getDefaultExecutor()

Get default executor for this task.

Subclasses are expected to implement this if the zero-arg variant of start is used.

Returns:

the standard Executor used by this task

getTimeoutPeriod

protected long getTimeoutPeriod()

Get the timeout period for this task.

Generally this returns 0, but subclasses may override to indicate the amount of time to wait for the next task to be submitted to the Executor. If more than the specified time elapses before a subsequent task is submitted, the Executor will invoke timeout on this task.

Returns:

the timeout period (in milliseconds) in effect for this task

getExecutor

protected Executor getExecutor()

Get current active executor for this task.

Returns null if the Task has not been started.

Returns:

the current active executor for this task

complete

protected void complete(Object returnValue,
                        Throwable error)

Notification by the ExecutionService that the call is complete.

This posts an invokeLater for the finish operation.

Parameters:

returnValue - the result of the call method

error - any error that occurred during call

markCompleted

protected void markCompleted(Object returnValue,
                             Throwable error)

mark this task as completed.

Called as part of complete, and performs all actions except ensureing finish is called.

Parameters:

returnValue - the result of the call method

error - any error that occurred during call

call

public abstract Object call()
                     throws Exception

Compute the value to be returned by the get method.

This is analgous to construct in the SwingWorker class.

Returns:

the result of the call

Throws:

Exception - if the operation fails

finish

public void finish()

Allow event dispatching thread to complete the task after the call method has returned.

This is analgous to finished in the SwingWorker class.

timeout

public void timeout()

Allow timeout to be performed.

Executes in executor's thread, and is called for tasks that return a positive value for getTimeoutPeriod and when the subsequent task submitted to the Executor does not occur within the specified period.

get

public Object get()

Return the value created by the call method.

Returns null if an exception occurred in the call method.

Returns:

the value created by the call method

getThrowable

public Throwable getThrowable()

Return the value created by the call method.

Returns null if no exception occurred in the call method.

Returns:

the value created by the call method

isFailed

public boolean isFailed()

Return true if call failed.

Returns:

true if the call method has failed; false otherwise

isDone

public boolean isDone()

Return true if call has completed.

Returns:

true if the call method has completed; false otherwise