io.atlassian.util.concurrent

Class SettableFuture<T>

java.lang.Object

io.atlassian.util.concurrent.SettableFuture<T>

All Implemented Interfaces:

Future<T>

@ThreadSafe
public class SettableFuture<T>
extends Object
implements Future<T>

SettableFuture is a Future implementation where the responsibility for producing the result is external to the future instance, unlike FutureTask where the future holds the operation (a Callable or Runnable instance) and the first thread that calls FutureTask.run() executes the operation.

This is useful in situations where all the inputs may not be available at construction time.

Constructor Summary

Constructors

Constructor and Description
SettableFuture()

Method Summary

Modifier and Type	Method and Description
boolean	cancel(boolean mayInterruptIfRunning)
T	get() Get the value of the future.
T	get(long timeout, TimeUnit unit)
boolean	isCancelled()
boolean	isDone()
SettableFuture<T>	set(T value) Set the value returned by get() and get(long, TimeUnit)
SettableFuture<T>	setException(Throwable throwable) Set the exception thrown as the causal exception of an ExecutionException by get() and get(long, TimeUnit)

Methods inherited from class java.lang.Object

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

Constructor Detail

SettableFuture

public SettableFuture()

Method Detail

set

public final SettableFuture<T> set(T value)

Set the value returned by get() and get(long, TimeUnit)

Note that this can only be done once unless the value of the second set equals the first value otherwise an exception will be thrown. It also cannot be set if this future has been cancelled or an exception has been set.

Parameters:

value - the value to be set.

Returns:

a SettableFuture object.

setException

public final SettableFuture<T> setException(Throwable throwable)

Set the exception thrown as the causal exception of an ExecutionException by get() and get(long, TimeUnit)

Note that this can only be done once unless the value of the second setException(Throwable) equals the first value otherwise an exception will be thrown (as most exceptions do not implement equals this effectively means the same reference). It also cannot be set if this future has been cancelled or a a value has been set.

Parameters:

throwable - a Throwable.

Returns:

a SettableFuture.

get

public final T get()
            throws InterruptedException,
                   ExecutionException

Get the value of the future. Blocking

Specified by:

get in interface Future<T>

Returns:

a T.

Throws:

InterruptedException - if any.

ExecutionException - if any.

get

public final T get(long timeout,
                   TimeUnit unit)
            throws InterruptedException,
                   ExecutionException,
                   TimeoutException

Specified by:

get in interface Future<T>

Throws:

InterruptedException

ExecutionException

TimeoutException

isDone

public final boolean isDone()

Specified by:

isDone in interface Future<T>

isCancelled

public final boolean isCancelled()

Specified by:

isCancelled in interface Future<T>

cancel

public final boolean cancel(boolean mayInterruptIfRunning)

Specified by:

cancel in interface Future<T>