IFuture Interface

Definition

[Android.Runtime.Register("java/util/concurrent/Future", "", "Java.Util.Concurrent.IFutureInvoker")]
[Java.Interop.JavaTypeParameters(new System.String[] { "V" })]
public interface IFuture : Android.Runtime.IJavaObject, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("java/util/concurrent/Future", "", "Java.Util.Concurrent.IFutureInvoker")>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "V" })>]
type IFuture = interface
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Derived

Java.Util.Concurrent.CompletableFuture

Java.Util.Concurrent.ForkJoinTask

Java.Util.Concurrent.FutureTask

Java.Util.Concurrent.IRunnableFuture

Java.Util.Concurrent.IRunnableScheduledFuture

More…

Attributes

RegisterAttribute JavaTypeParametersAttribute

Implements

IJavaObject IJavaPeerable IDisposable

Remarks

A Future represents the result of an asynchronous computation. Methods are provided to check if the computation is complete, to wait for its completion, and to retrieve the result of the computation. The result can only be retrieved using method get when the computation has completed, blocking if necessary until it is ready. Cancellation is performed by the cancel method. Additional methods are provided to determine if the task completed normally or was cancelled. Once a computation has completed, the computation cannot be cancelled. If you would like to use a Future for the sake of cancellability but not provide a usable result, you can declare types of the form Future<?> and return null as a result of the underlying task.

<b>Sample Usage</b> (Note that the following classes are all made-up.)

{@code
            interface ArchiveSearcher { String search(String target); }
            class App {
              ExecutorService executor = ...;
              ArchiveSearcher searcher = ...;
              void showSearch(String target) throws InterruptedException {
                Callable<String> task = () -> searcher.search(target);
                Future<String> future = executor.submit(task);
                displayOtherThings(); // do other things while searching
                try {
                  displayText(future.get()); // use future
                } catch (ExecutionException ex) { cleanup(); return; }
              }
            }}

The FutureTask class is an implementation of Future that implements Runnable, and so may be executed by an Executor. For example, the above construction with submit could be replaced by:

{@code
            FutureTask<String> future = new FutureTask<>(task);
            executor.execute(future);}

Memory consistency effects: Actions taken by the asynchronous computation <i>happen-before</i> actions following the corresponding Future.get() in another thread.

Added in 1.5.

Java documentation for java.util.concurrent.Future.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Properties

Methods

Extension Methods

Applies to