com.google.common.util.concurrent

Class Futures.ImmediateFuture<V>

java.lang.Object

com.google.common.util.concurrent.Futures.ImmediateFuture<V>

All Implemented Interfaces:

ListenableFuture<V>, java.util.concurrent.Future<V>

Direct Known Subclasses:

Futures.ImmediateCancelledFuture, Futures.ImmediateFailedCheckedFuture, Futures.ImmediateFailedFuture, Futures.ImmediateSuccessfulCheckedFuture, Futures.ImmediateSuccessfulFuture

Enclosing class:

Futures

private abstract static class Futures.ImmediateFuture<V>
extends java.lang.Object
implements ListenableFuture<V>

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.logging.Logger	log

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ImmediateFuture()

Method Summary

Modifier and Type	Method and Description
void	addListener(java.lang.Runnable listener, java.util.concurrent.Executor executor) Registers a listener to be run on the given executor.
boolean	cancel(boolean mayInterruptIfRunning)
abstract V	get()
V	get(long timeout, java.util.concurrent.TimeUnit unit)
boolean	isCancelled()
boolean	isDone()

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final java.util.logging.Logger log

Constructor Detail

ImmediateFuture

private ImmediateFuture()

Method Detail

addListener

public void addListener(java.lang.Runnable listener,
                        java.util.concurrent.Executor executor)

Description copied from interface: ListenableFuture

Registers a listener to be run on the given executor. The listener will run when the Future's computation is complete or, if the computation is already complete, immediately.

There is no guaranteed ordering of execution of listeners, but any listener added through this method is guaranteed to be called once the computation is complete.

Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown during Executor.execute (e.g., a RejectedExecutionException or an exception thrown by direct execution) will be caught and logged.

Note: For fast, lightweight listeners that would be safe to execute in any thread, consider MoreExecutors.directExecutor(). For heavier listeners, directExecutor() carries some caveats. For example, the listener may run on an unpredictable or undesirable thread:

• If this Future is done at the time addListener is called, addListener will execute the listener inline.
• If this Future is not yet done, addListener will schedule the listener to be run by the thread that completes this Future, which may be an internal system thread such as an RPC network thread.

Also note that, regardless of which thread executes the directExecutor() listener, all other registered but unexecuted listeners are prevented from running during its execution, even if those listeners are to run in other executors.

This is the most general listener interface. For common operations performed using listeners, see Futures. For a simplified but general listener interface, see addCallback().

Specified by:

addListener in interface ListenableFuture<V>

Parameters:

listener - the listener to run when the computation is complete

executor - the executor to run the listener in

cancel

public boolean cancel(boolean mayInterruptIfRunning)

Specified by:

cancel in interface java.util.concurrent.Future<V>

get

public abstract V get()
               throws java.util.concurrent.ExecutionException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.util.concurrent.ExecutionException

get

public V get(long timeout,
             java.util.concurrent.TimeUnit unit)
      throws java.util.concurrent.ExecutionException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.util.concurrent.ExecutionException

isCancelled

public boolean isCancelled()

Specified by:

isCancelled in interface java.util.concurrent.Future<V>

isDone

public boolean isDone()

Specified by:

isDone in interface java.util.concurrent.Future<V>