com.sun.sgs.impl.nio
Class IoFutureTask<R,A>

java.lang.Object
  java.util.concurrent.FutureTask<R>
      com.sun.sgs.impl.nio.IoFutureTask<R,A>

Type Parameters:

R - the result type

A - the attachment type

All Implemented Interfaces:

IoFuture<R,A>, Runnable, Future<R>, RunnableFuture<R>

Direct Known Subclasses:

DelegatingCompletionHandler

public class IoFutureTask<R,A>
extends FutureTask<R>
implements IoFuture<R,A>

An implementation of IoFuture that adds an object attachment to a FutureTask.

Constructor Summary

IoFutureTask(Callable<R> callable, A attachment)
Creates an instance of this class for running the specified Callable and including the specified attachment.

Method Summary

A	attach(A newAttachment) Attaches the given object to this channel future.
A	attachment() Retrieves the current attachment.
R	getNow() Retrieves the result of a completed operation.
static <R,A> IoFuture	newInstance(Callable<R> callable, A attachment) Creates an instance of this class for running the specified Callable and including the specified attachment.

Methods inherited from class java.util.concurrent.FutureTask

cancel, done, get, get, isCancelled, isDone, run, runAndReset, set, setException

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sun.sgs.nio.channels.IoFuture

cancel

Methods inherited from interface java.util.concurrent.Future

get, get, isCancelled, isDone

Constructor Detail

IoFutureTask

public IoFutureTask(Callable<R> callable,
                    A attachment)

Creates an instance of this class for running the specified Callable and including the specified attachment.

Parameters:

callable - the callable task

attachment - the attachment; may be null

Method Detail

newInstance

public static <R,A> IoFuture newInstance(Callable<R> callable,
                                         A attachment)

Creates an instance of this class for running the specified Callable and including the specified attachment.

Type Parameters:

R - the result type

A - the attachment type

Parameters:

callable - the callable task

attachment - the attachment; may be null

Returns:

a new IoFuture

getNow

public R getNow()
         throws ExecutionException

Retrieves the result of a completed operation.

The method is intended to be invoked from a CompletionHandler to retrieve the result of a completed operation. It is equivalent to invoking the get method to retrieve the result except that the method does not wait for the result.

Specified by:

getNow in interface IoFuture<R,A>

Returns:

the completed result

Throws:

ExecutionException - if the operation threw an exception

attachment

public A attachment()

Retrieves the current attachment.

Specified by:

attachment in interface IoFuture<R,A>

Returns:

the object currently attached to this channel future or null if there is no attachment

attach

public A attach(A newAttachment)

Attaches the given object to this channel future.

An attached object may later be retrieved via the attachment method. Only one object may be attached at a time; invoking this method causes any previous attachment to be discarded. The current attachment may be discarded by attaching null.

Specified by:

attach in interface IoFuture<R,A>

Parameters:

newAttachment - the object to be attached; may be null

Returns:

the previously-attached object, if any, otherwise null