public classCompletableFuture<T>extendsObjectimplementsFuture<T>,CompletionStage<T>
Future that may be explicitly completed (setting its value and status), and may be used as aCompletionStage, supporting dependent functions and actions that trigger upon its completion.When two or more threads attempt tocomplete,completeExceptionally, orcancel a CompletableFuture, only one of them succeeds.
In addition to these and related methods for directly manipulating status and results, CompletableFuture implements interfaceCompletionStage with the following policies:
ForkJoinPool.commonPool() (unless it does not support a parallelism level of at least two, in which case, a new Thread is created to run each task). To simplify monitoring, debugging, and tracking, all generated asynchronous tasks are instances of the marker interfaceCompletableFuture.AsynchronousCompletionTask.CompletableFuture also implementsFuture with the following policies:
FutureTask) this class has no direct control over the computation that causes it to be completed, cancellation is treated as just another form of exceptional completion. Methodcancel has the same effect ascompleteExceptionally(new CancellationException()). MethodisCompletedExceptionally() can be used to determine if a CompletableFuture completed in any exceptional fashion.get() andget(long, TimeUnit) throw anExecutionException with the same cause as held in the corresponding CompletionException. To simplify usage in most contexts, this class also defines methodsjoin() andgetNow(T) that instead throw the CompletionException directly in these cases.| Modifier and Type | Class | Description |
|---|---|---|
static interface | CompletableFuture.AsynchronousCompletionTask | A marker interface identifying asynchronous tasks produced by async methods. |
| Constructor | Description |
|---|---|
CompletableFuture() | Creates a new incomplete CompletableFuture. |
| Modifier and Type | Method | Description |
|---|---|---|
CompletableFuture<Void> | acceptEither(CompletionStage<? extendsT> other,Consumer<? superT> action) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed with the corresponding result as argument to the supplied action. |
CompletableFuture<Void> | acceptEitherAsync(CompletionStage<? extendsT> other,Consumer<? superT> action) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using this stage's default asynchronous execution facility, with the corresponding result as argument to the supplied action. |
CompletableFuture<Void> | acceptEitherAsync(CompletionStage<? extendsT> other,Consumer<? superT> action,Executor executor) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using the supplied executor, with the corresponding result as argument to the supplied function. |
staticCompletableFuture<Void> | allOf(CompletableFuture<?>... cfs) | Returns a new CompletableFuture that is completed when all of the given CompletableFutures complete. |
staticCompletableFuture<Object> | anyOf(CompletableFuture<?>... cfs) | Returns a new CompletableFuture that is completed when any of the given CompletableFutures complete, with the same result. |
<U> CompletableFuture<U> | applyToEither(CompletionStage<? extendsT> other,Function<? superT,U> fn) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed with the corresponding result as argument to the supplied function. |
<U> CompletableFuture<U> | applyToEitherAsync(CompletionStage<? extendsT> other,Function<? superT,U> fn) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using this stage's default asynchronous execution facility, with the corresponding result as argument to the supplied function. |
<U> CompletableFuture<U> | applyToEitherAsync(CompletionStage<? extendsT> other,Function<? superT,U> fn,Executor executor) | Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using the supplied executor, with the corresponding result as argument to the supplied function. |
boolean | cancel(boolean mayInterruptIfRunning) | If not already completed, completes this CompletableFuture with a CancellationException. |
boolean | complete(T value) | If not already completed, sets the value returned by get() and related methods to the given value. |
static <U> CompletableFuture<U> | completedFuture(U value) | Returns a new CompletableFuture that is already completed with the given value. |
boolean | completeExceptionally(Throwable ex) | If not already completed, causes invocations of get() and related methods to throw the given exception. |
CompletableFuture<T> | exceptionally(Function<Throwable,? extendsT> fn) | Returns a new CompletableFuture that is completed when this CompletableFuture completes, with the result of the given function of the exception triggering this CompletableFuture's completion when it completes exceptionally; otherwise, if this CompletableFuture completes normally, then the returned CompletableFuture also completes normally with the same value. |
T | get() | Waits if necessary for this future to complete, and then returns its result. |
T | get(long timeout,TimeUnit unit) | Waits if necessary for at most the given time for this future to complete, and then returns its result, if available. |
T | getNow(T valueIfAbsent) | Returns the result value (or throws any encountered exception) if completed, else returns the given valueIfAbsent. |
int | getNumberOfDependents() | Returns the estimated number of CompletableFutures whose completions are awaiting completion of this CompletableFuture. |
<U> CompletableFuture<U> | handle(BiFunction<? superT,Throwable,? extends U> fn) | Returns a new CompletionStage that, when this stage completes either normally or exceptionally, is executed with this stage's result and exception as arguments to the supplied function. |
<U> CompletableFuture<U> | handleAsync(BiFunction<? superT,Throwable,? extends U> fn) | Returns a new CompletionStage that, when this stage completes either normally or exceptionally, is executed using this stage's default asynchronous execution facility, with this stage's result and exception as arguments to the supplied function. |
<U> CompletableFuture<U> | handleAsync(BiFunction<? superT,Throwable,? extends U> fn,Executor executor) | Returns a new CompletionStage that, when this stage completes either normally or exceptionally, is executed using the supplied executor, with this stage's result and exception as arguments to the supplied function. |
boolean | isCancelled() | Returns true if this CompletableFuture was cancelled before it completed normally. |
boolean | isCompletedExceptionally() | Returns true if this CompletableFuture completed exceptionally, in any way. |
boolean | isDone() | Returns true if completed in any fashion: normally, exceptionally, or via cancellation. |
T | join() | Returns the result value when complete, or throws an (unchecked) exception if completed exceptionally. |
void | obtrudeException(Throwable ex) | Forcibly causes subsequent invocations of method get() and related methods to throw the given exception, whether or not already completed. |
void | obtrudeValue(T value) | Forcibly sets or resets the value subsequently returned by method get() and related methods, whether or not already completed. |
CompletableFuture<Void> | runAfterBoth(CompletionStage<?> other,Runnable action) | Returns a new CompletionStage that, when this and the other given stage both complete normally, executes the given action. |
CompletableFuture<Void> | runAfterBothAsync(CompletionStage<?> other,Runnable action) | Returns a new CompletionStage that, when this and the other given stage complete normally, executes the given action using this stage's default asynchronous execution facility. |
CompletableFuture<Void> | runAfterBothAsync(CompletionStage<?> other,Runnable action,Executor executor) | Returns a new CompletionStage that, when this and the other given stage complete normally, executes the given action using the supplied executor. |
CompletableFuture<Void> | runAfterEither(CompletionStage<?> other,Runnable action) | Returns a new CompletionStage that, when either this or the other given stage complete normally, executes the given action. |
CompletableFuture<Void> | runAfterEitherAsync(CompletionStage<?> other,Runnable action) | Returns a new CompletionStage that, when either this or the other given stage complete normally, executes the given action using this stage's default asynchronous execution facility. |
CompletableFuture<Void> | runAfterEitherAsync(CompletionStage<?> other,Runnable action,Executor executor) | Returns a new CompletionStage that, when either this or the other given stage complete normally, executes the given action using the supplied executor. |
staticCompletableFuture<Void> | runAsync(Runnable runnable) | Returns a new CompletableFuture that is asynchronously completed by a task running in the ForkJoinPool.commonPool() after it runs the given action. |
staticCompletableFuture<Void> | runAsync(Runnable runnable,Executor executor) | Returns a new CompletableFuture that is asynchronously completed by a task running in the given executor after it runs the given action. |
static <U> CompletableFuture<U> | supplyAsync(Supplier<U> supplier) | Returns a new CompletableFuture that is asynchronously completed by a task running in the ForkJoinPool.commonPool() with the value obtained by calling the given Supplier. |
static <U> CompletableFuture<U> | supplyAsync(Supplier<U> supplier,Executor executor) | Returns a new CompletableFuture that is asynchronously completed by a task running in the given executor with the value obtained by calling the given Supplier. |
CompletableFuture<Void> | thenAccept(Consumer<? superT> action) | Returns a new CompletionStage that, when this stage completes normally, is executed with this stage's result as the argument to the supplied action. |
CompletableFuture<Void> | thenAcceptAsync(Consumer<? superT> action) | Returns a new CompletionStage that, when this stage completes normally, is executed using this stage's default asynchronous execution facility, with this stage's result as the argument to the supplied action. |
CompletableFuture<Void> | thenAcceptAsync(Consumer<? superT> action,Executor executor) | Returns a new CompletionStage that, when this stage completes normally, is executed using the supplied Executor, with this stage's result as the argument to the supplied action. |
<U> CompletableFuture<Void> | thenAcceptBoth(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action) | Returns a new CompletionStage that, when this and the other given stage both complete normally, is executed with the two results as arguments to the supplied action. |
<U> CompletableFuture<Void> | thenAcceptBothAsync(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action) | Returns a new CompletionStage that, when this and the other given stage complete normally, is executed using this stage's default asynchronous execution facility, with the two results as arguments to the supplied action. |
<U> CompletableFuture<Void> | thenAcceptBothAsync(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action,Executor executor) | Returns a new CompletionStage that, when this and the other given stage complete normally, is executed using the supplied executor, with the two results as arguments to the supplied function. |
<U> CompletableFuture<U> | thenApply(Function<? superT,? extends U> fn) | Returns a new CompletionStage that, when this stage completes normally, is executed with this stage's result as the argument to the supplied function. |
<U> CompletableFuture<U> | thenApplyAsync(Function<? superT,? extends U> fn) | Returns a new CompletionStage that, when this stage completes normally, is executed using this stage's default asynchronous execution facility, with this stage's result as the argument to the supplied function. |
<U> CompletableFuture<U> | thenApplyAsync(Function<? superT,? extends U> fn,Executor executor) | Returns a new CompletionStage that, when this stage completes normally, is executed using the supplied Executor, with this stage's result as the argument to the supplied function. |
<U,V> CompletableFuture<V> | thenCombine(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn) | Returns a new CompletionStage that, when this and the other given stage both complete normally, is executed with the two results as arguments to the supplied function. |
<U,V> CompletableFuture<V> | thenCombineAsync(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn) | Returns a new CompletionStage that, when this and the other given stage complete normally, is executed using this stage's default asynchronous execution facility, with the two results as arguments to the supplied function. |
<U,V> CompletableFuture<V> | thenCombineAsync(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn,Executor executor) | Returns a new CompletionStage that, when this and the other given stage complete normally, is executed using the supplied executor, with the two results as arguments to the supplied function. |
<U> CompletableFuture<U> | thenCompose(Function<? superT,? extendsCompletionStage<U>> fn) | Returns a new CompletionStage that, when this stage completes normally, is executed with this stage as the argument to the supplied function. |
<U> CompletableFuture<U> | thenComposeAsync(Function<? superT,? extendsCompletionStage<U>> fn) | Returns a new CompletionStage that, when this stage completes normally, is executed using this stage's default asynchronous execution facility, with this stage as the argument to the supplied function. |
<U> CompletableFuture<U> | thenComposeAsync(Function<? superT,? extendsCompletionStage<U>> fn,Executor executor) | Returns a new CompletionStage that, when this stage completes normally, is executed using the supplied Executor, with this stage's result as the argument to the supplied function. |
CompletableFuture<Void> | thenRun(Runnable action) | Returns a new CompletionStage that, when this stage completes normally, executes the given action. |
CompletableFuture<Void> | thenRunAsync(Runnable action) | Returns a new CompletionStage that, when this stage completes normally, executes the given action using this stage's default asynchronous execution facility. |
CompletableFuture<Void> | thenRunAsync(Runnable action,Executor executor) | Returns a new CompletionStage that, when this stage completes normally, executes the given action using the supplied Executor. |
CompletableFuture<T> | toCompletableFuture() | Returns this CompletableFuture. |
String | toString() | Returns a string identifying this CompletableFuture, as well as its completion state. |
CompletableFuture<T> | whenComplete(BiConsumer<? superT,? superThrowable> action) | Returns a new CompletionStage with the same result or exception as this stage, that executes the given action when this stage completes. |
CompletableFuture<T> | whenCompleteAsync(BiConsumer<? superT,? superThrowable> action) | Returns a new CompletionStage with the same result or exception as this stage, that executes the given action using this stage's default asynchronous execution facility when this stage completes. |
CompletableFuture<T> | whenCompleteAsync(BiConsumer<? superT,? superThrowable> action,Executor executor) | Returns a new CompletionStage with the same result or exception as this stage, that executes the given action using the supplied Executor when this stage completes. |
public CompletableFuture()
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier)
ForkJoinPool.commonPool() with the value obtained by calling the given Supplier.U - the function's return typesupplier - a function returning the value to be used to complete the returned CompletableFuturepublic static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier,Executor executor)
U - the function's return typesupplier - a function returning the value to be used to complete the returned CompletableFutureexecutor - the executor to use for asynchronous executionpublic static CompletableFuture<Void> runAsync(Runnable runnable)
ForkJoinPool.commonPool() after it runs the given action.runnable - the action to run before completing the returned CompletableFuturepublic static CompletableFuture<Void> runAsync(Runnable runnable,Executor executor)
runnable - the action to run before completing the returned CompletableFutureexecutor - the executor to use for asynchronous executionpublic static <U> CompletableFuture<U> completedFuture(U value)
U - the type of the valuevalue - the valuepublic boolean isDone()
true if completed in any fashion: normally, exceptionally, or via cancellation.public T get() throwsInterruptedException,ExecutionException
get in interface Future<T>CancellationException - if this future was cancelledExecutionException - if this future completed exceptionallyInterruptedException - if the current thread was interrupted while waitingpublic T get(long timeout,TimeUnit unit) throwsInterruptedException,ExecutionException,TimeoutException
get in interface Future<T>timeout - the maximum time to waitunit - the time unit of the timeout argumentCancellationException - if this future was cancelledExecutionException - if this future completed exceptionallyInterruptedException - if the current thread was interrupted while waitingTimeoutException - if the wait timed outpublic T join()
CompletionException with the underlying exception as its cause.CancellationException - if the computation was cancelledCompletionException - if this future completed exceptionally or a completion computation threw an exceptionpublic T getNow(T valueIfAbsent)
valueIfAbsent - the value to return if not completedCancellationException - if the computation was cancelledCompletionException - if this future completed exceptionally or a completion computation threw an exceptionpublic boolean complete(T value)
get() and related methods to the given value.value - the result valuetrue if this invocation caused this CompletableFuture to transition to a completed state, elsefalsepublic boolean completeExceptionally(Throwable ex)
get() and related methods to throw the given exception.ex - the exceptiontrue if this invocation caused this CompletableFuture to transition to a completed state, elsefalsepublic <U> CompletableFuture<U> thenApply(Function<? superT,? extends U> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenApply in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> thenApplyAsync(Function<? superT,? extends U> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenApplyAsync in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> thenApplyAsync(Function<? superT,? extends U> fn,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenApplyAsync in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<Void> thenAccept(Consumer<? superT> action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenAccept in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> thenAcceptAsync(Consumer<? superT> action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenAcceptAsync in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> thenAcceptAsync(Consumer<? superT> action,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenAcceptAsync in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<Void> thenRun(Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenRun in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> thenRunAsync(Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenRunAsync in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> thenRunAsync(Runnable action,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenRunAsync in interface CompletionStage<T>action - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic <U,V> CompletableFuture<V> thenCombine(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenCombine in interface CompletionStage<T>U - the type of the other CompletionStage's resultV - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStagepublic <U,V> CompletableFuture<V> thenCombineAsync(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenCombineAsync in interface CompletionStage<T>U - the type of the other CompletionStage's resultV - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStagepublic <U,V> CompletableFuture<V> thenCombineAsync(CompletionStage<? extends U> other,BiFunction<? superT,? super U,? extends V> fn,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenCombineAsync in interface CompletionStage<T>U - the type of the other CompletionStage's resultV - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic <U> CompletableFuture<Void> thenAcceptBoth(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenAcceptBoth in interface CompletionStage<T>U - the type of the other CompletionStage's resultother - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic <U> CompletableFuture<Void> thenAcceptBothAsync(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action)
CompletionStagethenAcceptBothAsync in interface CompletionStage<T>U - the type of the other CompletionStage's resultother - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic <U> CompletableFuture<Void> thenAcceptBothAsync(CompletionStage<? extends U> other,BiConsumer<? superT,? super U> action,Executor executor)
CompletionStagethenAcceptBothAsync in interface CompletionStage<T>U - the type of the other CompletionStage's resultother - the other CompletionStageaction - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<Void> runAfterBoth(CompletionStage<?> other,Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterBoth in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other,Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterBothAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other,Runnable action,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterBothAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic <U> CompletableFuture<U> applyToEither(CompletionStage<? extendsT> other,Function<? superT,U> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.applyToEither in interface CompletionStage<T>U - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> applyToEitherAsync(CompletionStage<? extendsT> other,Function<? superT,U> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.applyToEitherAsync in interface CompletionStage<T>U - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> applyToEitherAsync(CompletionStage<? extendsT> other,Function<? superT,U> fn,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.applyToEitherAsync in interface CompletionStage<T>U - the function's return typeother - the other CompletionStagefn - the function to use to compute the value of the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<Void> acceptEither(CompletionStage<? extendsT> other,Consumer<? superT> action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.acceptEither in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> acceptEitherAsync(CompletionStage<? extendsT> other,Consumer<? superT> action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.acceptEitherAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> acceptEitherAsync(CompletionStage<? extendsT> other,Consumer<? superT> action,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.acceptEitherAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<Void> runAfterEither(CompletionStage<?> other,Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterEither in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other,Runnable action)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterEitherAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStagepublic CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other,Runnable action,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.runAfterEitherAsync in interface CompletionStage<T>other - the other CompletionStageaction - the action to perform before completing the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic <U> CompletableFuture<U> thenCompose(Function<? superT,? extendsCompletionStage<U>> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenCompose in interface CompletionStage<T>U - the type of the returned CompletionStage's resultfn - the function returning a new CompletionStagepublic <U> CompletableFuture<U> thenComposeAsync(Function<? superT,? extendsCompletionStage<U>> fn)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenComposeAsync in interface CompletionStage<T>U - the type of the returned CompletionStage's resultfn - the function returning a new CompletionStagepublic <U> CompletableFuture<U> thenComposeAsync(Function<? superT,? extendsCompletionStage<U>> fn,Executor executor)
CompletionStageCompletionStage documentation for rules covering exceptional completion.thenComposeAsync in interface CompletionStage<T>U - the type of the returned CompletionStage's resultfn - the function returning a new CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<T> whenComplete(BiConsumer<? superT,? superThrowable> action)
CompletionStageWhen this stage is complete, the given action is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments. The returned stage is completed when the action returns. If the supplied action itself encounters an exception, then the returned stage exceptionally completes with this exception unless this stage also completed exceptionally.
whenComplete in interface CompletionStage<T>action - the action to performpublic CompletableFuture<T> whenCompleteAsync(BiConsumer<? superT,? superThrowable> action)
CompletionStageWhen this stage is complete, the given action is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments. The returned stage is completed when the action returns. If the supplied action itself encounters an exception, then the returned stage exceptionally completes with this exception unless this stage also completed exceptionally.
whenCompleteAsync in interface CompletionStage<T>action - the action to performpublic CompletableFuture<T> whenCompleteAsync(BiConsumer<? superT,? superThrowable> action,Executor executor)
CompletionStageWhen this stage is complete, the given action is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments. The returned stage is completed when the action returns. If the supplied action itself encounters an exception, then the returned stage exceptionally completes with this exception unless this stage also completed exceptionally.
whenCompleteAsync in interface CompletionStage<T>action - the action to performexecutor - the executor to use for asynchronous executionpublic <U> CompletableFuture<U> handle(BiFunction<? superT,Throwable,? extends U> fn)
CompletionStageWhen this stage is complete, the given function is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments, and the function's result is used to complete the returned stage.
handle in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> handleAsync(BiFunction<? superT,Throwable,? extends U> fn)
CompletionStageWhen this stage is complete, the given function is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments, and the function's result is used to complete the returned stage.
handleAsync in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStagepublic <U> CompletableFuture<U> handleAsync(BiFunction<? superT,Throwable,? extends U> fn,Executor executor)
CompletionStageWhen this stage is complete, the given function is invoked with the result (ornull if none) and the exception (ornull if none) of this stage as arguments, and the function's result is used to complete the returned stage.
handleAsync in interface CompletionStage<T>U - the function's return typefn - the function to use to compute the value of the returned CompletionStageexecutor - the executor to use for asynchronous executionpublic CompletableFuture<T> toCompletableFuture()
toCompletableFuture in interface CompletionStage<T>public CompletableFuture<T> exceptionally(Function<Throwable,? extendsT> fn)
whenComplete andhandle.exceptionally in interface CompletionStage<T>fn - the function to use to compute the value of the returned CompletableFuture if this CompletableFuture completed exceptionallypublic static CompletableFuture<Void> allOf(CompletableFuture<?>... cfs)
null.Among the applications of this method is to await completion of a set of independent CompletableFutures before continuing a program, as in:CompletableFuture.allOf(c1, c2, c3).join();.
cfs - the CompletableFuturesNullPointerException - if the array or any of its elements arenullpublic static CompletableFuture<Object> anyOf(CompletableFuture<?>... cfs)
cfs - the CompletableFuturesNullPointerException - if the array or any of its elements arenullpublic boolean cancel(boolean mayInterruptIfRunning)
CancellationException. Dependent CompletableFutures that have not already completed will also complete exceptionally, with aCompletionException caused by thisCancellationException.public boolean isCancelled()
true if this CompletableFuture was cancelled before it completed normally.isCancelled in interface Future<T>true if this CompletableFuture was cancelled before it completed normallypublic boolean isCompletedExceptionally()
true if this CompletableFuture completed exceptionally, in any way. Possible causes include cancellation, explicit invocation ofcompleteExceptionally, and abrupt termination of a CompletionStage action.true if this CompletableFuture completed exceptionallypublic void obtrudeValue(T value)
get() and related methods, whether or not already completed. This method is designed for use only in error recovery actions, and even in such situations may result in ongoing dependent completions using established versus overwritten outcomes.value - the completion valuepublic void obtrudeException(Throwable ex)
get() and related methods to throw the given exception, whether or not already completed. This method is designed for use only in error recovery actions, and even in such situations may result in ongoing dependent completions using established versus overwritten outcomes.ex - the exceptionNullPointerException - if the exception is nullpublic int getNumberOfDependents()
public String toString()
"Completed Normally" or the String"Completed Exceptionally", or the String"Not completed" followed by the number of CompletableFutures dependent upon its completion, if any.