Class PromiseImpl<T>

    • Field Detail

      • factory

        private final PromiseFactory factory
        The factory to use for callbacks and scheduled operations.
      • callbacks

        private final java.util.concurrent.ConcurrentLinkedQueue<java.lang.Runnable> callbacks
        A ConcurrentLinkedQueue to hold the callbacks for this Promise, so no additional synchronization is required to write to or read from the queue.
    • Constructor Detail

      • PromiseImpl

        PromiseImpl​(PromiseFactory factory)
        Initialize this Promise.
        Parameters:
        factory - The factory to use for callbacks and scheduled operations.
    • Method Detail

      • failed

        <V> FailedPromiseImpl<V> failed​(java.lang.Throwable f)
        Return a new FailedPromiseImpl using the PromiseFactory of this PromiseImpl.
        Parameters:
        f - Failure for the FailedPromiseImpl.
        Returns:
        A new FailedPromiseImpl.
        Since:
        1.1
      • onResolve

        public Promise<T> onResolve​(java.lang.Runnable callback)
        Register a callback to be called when this Promise is resolved.

        The specified callback is called when this Promise is resolved either successfully or with a failure.

        This method may be called at any time including before and after this Promise has been resolved.

        Resolving this Promise happens-before any registered callback is called. That is, in a registered callback, Promise.isDone() must return true and Promise.getValue() and Promise.getFailure() must not block.

        A callback may be called on a different thread than the thread which registered the callback. So the callback must be thread safe but can rely upon that the registration of the callback happens-before the registered callback is called.

        Specified by:
        onResolve in interface Promise<T>
        Parameters:
        callback - The callback to be called when this Promise is resolved. Must not be null.
        Returns:
        This Promise.
      • notifyCallbacks

        void notifyCallbacks()
        Call any registered callbacks if this Promise is resolved.
      • schedule

        java.util.concurrent.ScheduledFuture<?> schedule​(java.lang.Runnable operation,
                                                         long delay,
                                                         java.util.concurrent.TimeUnit unit)
        Schedule a operation on the scheduled executor.
        Since:
        1.1
      • uncaughtException

        static void uncaughtException​(java.lang.Throwable t)
        Handle an uncaught exception from a Runnable.
        Parameters:
        t - The uncaught exception.
        Since:
        1.1
      • chain

        static <V> void chain​(Promise<V> promise,
                              java.lang.Runnable chain)
        Run the specified chain when the specified promise is resolved.
        Parameters:
        promise - The promise associated with the chain.
        chain - The chain to run when the promise is resolved.
      • onSuccess

        public Promise<T> onSuccess​(Consumer<? super T> success)
        Register a callback to be called with the result of this Promise when this Promise is resolved successfully. The callback will not be called if this Promise is resolved with a failure.

        This method may be called at any time including before and after this Promise has been resolved.

        Resolving this Promise happens-before any registered callback is called. That is, in a registered callback, Promise.isDone() must return true and Promise.getValue() and Promise.getFailure() must not block.

        A callback may be called on a different thread than the thread which registered the callback. So the callback must be thread safe but can rely upon that the registration of the callback happens-before the registered callback is called.

        Specified by:
        onSuccess in interface Promise<T>
        Parameters:
        success - The Consumer callback that receives the value of this Promise. Must not be null.
        Returns:
        This Promise.
      • onFailure

        public Promise<T> onFailure​(Consumer<? super java.lang.Throwable> failure)
        Register a callback to be called with the failure for this Promise when this Promise is resolved with a failure. The callback will not be called if this Promise is resolved successfully.

        This method may be called at any time including before and after this Promise has been resolved.

        Resolving this Promise happens-before any registered callback is called. That is, in a registered callback, Promise.isDone() must return true and Promise.getValue() and Promise.getFailure() must not block.

        A callback may be called on a different thread than the thread which registered the callback. So the callback must be thread safe but can rely upon that the registration of the callback happens-before the registered callback is called.

        Specified by:
        onFailure in interface Promise<T>
        Parameters:
        failure - The Consumer callback that receives the failure of this Promise. Must not be null.
        Returns:
        This Promise.
      • then

        public <R> Promise<R> then​(Success<? super T,​? extends R> success,
                                   Failure failure)
        Chain a new Promise to this Promise with Success and Failure callbacks.

        The specified Success callback is called when this Promise is successfully resolved and the specified Failure callback is called when this Promise is resolved with a failure.

        This method returns a new Promise which is chained to this Promise. The returned Promise must be resolved when this Promise is resolved after the specified Success or Failure callback is executed. The result of the executed callback must be used to resolve the returned Promise. Multiple calls to this method can be used to create a chain of promises which are resolved in sequence.

        If this Promise is successfully resolved, the Success callback is executed and the result Promise, if any, or thrown exception is used to resolve the returned Promise from this method. If this Promise is resolved with a failure, the Failure callback is executed and the returned Promise from this method is failed.

        This method may be called at any time including before and after this Promise has been resolved.

        Resolving this Promise happens-before any registered callback is called. That is, in a registered callback, Promise.isDone() must return true and Promise.getValue() and Promise.getFailure() must not block.

        A callback may be called on a different thread than the thread which registered the callback. So the callback must be thread safe but can rely upon that the registration of the callback happens-before the registered callback is called.

        Specified by:
        then in interface Promise<T>
        Type Parameters:
        R - The value type associated with the returned Promise.
        Parameters:
        success - The Success callback to be called when this Promise is successfully resolved. May be null if no Success callback is required. In this case, the returned Promise must be resolved with the value null when this Promise is successfully resolved.
        failure - The Failure callback to be called when this Promise is resolved with a failure. May be null if no Failure callback is required.
        Returns:
        A new Promise which is chained to this Promise. The returned Promise must be resolved when this Promise is resolved after the specified Success or Failure callback, if any, is executed.
      • then

        public <R> Promise<R> then​(Success<? super T,​? extends R> success)
        Chain a new Promise to this Promise with a Success callback.

        This method performs the same function as calling Promise.then(Success, Failure) with the specified Success callback and null for the Failure callback.

        Specified by:
        then in interface Promise<T>
        Type Parameters:
        R - The value type associated with the returned Promise.
        Parameters:
        success - The Success callback to be called when this Promise is successfully resolved. May be null if no Success callback is required. In this case, the returned Promise must be resolved with the value null when this Promise is successfully resolved.
        Returns:
        A new Promise which is chained to this Promise. The returned Promise must be resolved when this Promise is resolved after the specified Success, if any, is executed.
        See Also:
        Promise.then(Success, Failure)
      • thenAccept

        public Promise<T> thenAccept​(Consumer<? super T> consumer)
        Chain a new Promise to this Promise with a Consumer callback that receives the value of this Promise when it is successfully resolved.

        The specified Consumer is called when this Promise is resolved successfully.

        This method returns a new Promise which is chained to this Promise. The returned Promise must be resolved when this Promise is resolved after the specified callback is executed. If the callback throws an exception, the returned Promise is failed with that exception. Otherwise the returned Promise is resolved with the success value from this Promise.

        This method may be called at any time including before and after this Promise has been resolved.

        Resolving this Promise happens-before any registered callback is called. That is, in a registered callback, Promise.isDone() must return true and Promise.getValue() and Promise.getFailure() must not block.

        A callback may be called on a different thread than the thread which registered the callback. So the callback must be thread safe but can rely upon that the registration of the callback happens-before the registered callback is called.

        Specified by:
        thenAccept in interface Promise<T>
        Parameters:
        consumer - The Consumer callback that receives the value of this Promise. Must not be null.
        Returns:
        A new Promise which is chained to this Promise. The returned Promise must be resolved when this Promise is resolved after the specified Consumer is executed.
      • filter

        public Promise<T> filter​(Predicate<? super T> predicate)
        Filter the value of this Promise.

        If this Promise is successfully resolved, the returned Promise must either be resolved with the value of this Promise, if the specified Predicate accepts that value, or failed with a NoSuchElementException, if the specified Predicate does not accept that value. If the specified Predicate throws an exception, the returned Promise must be failed with the exception.

        If this Promise is resolved with a failure, the returned Promise must be failed with that failure.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        filter in interface Promise<T>
        Parameters:
        predicate - The Predicate to evaluate the value of this Promise. Must not be null.
        Returns:
        A Promise that filters the value of this Promise.
      • map

        public <R> Promise<R> map​(Function<? super T,​? extends R> mapper)
        Map the value of this Promise.

        If this Promise is successfully resolved, the returned Promise must be resolved with the value of specified Function as applied to the value of this Promise. If the specified Function throws an exception, the returned Promise must be failed with the exception.

        If this Promise is resolved with a failure, the returned Promise must be failed with that failure.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        map in interface Promise<T>
        Type Parameters:
        R - The value type associated with the returned Promise.
        Parameters:
        mapper - The Function that must map the value of this Promise to the value that must be used to resolve the returned Promise. Must not be null.
        Returns:
        A Promise that returns the value of this Promise as mapped by the specified Function.
      • flatMap

        public <R> Promise<R> flatMap​(Function<? super T,​Promise<? extends R>> mapper)
        FlatMap the value of this Promise.

        If this Promise is successfully resolved, the returned Promise must be resolved with the Promise from the specified Function as applied to the value of this Promise. If the specified Function throws an exception, the returned Promise must be failed with the exception.

        If this Promise is resolved with a failure, the returned Promise must be failed with that failure.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        flatMap in interface Promise<T>
        Type Parameters:
        R - The value type associated with the returned Promise.
        Parameters:
        mapper - The Function that must flatMap the value of this Promise to a Promise that must be used to resolve the returned Promise. Must not be null.
        Returns:
        A Promise that returns the value of this Promise as mapped by the specified Function.
      • recover

        public Promise<T> recover​(Function<Promise<?>,​? extends T> recovery)
        Recover from a failure of this Promise with a recovery value.

        If this Promise is successfully resolved, the returned Promise must be resolved with the value of this Promise.

        If this Promise is resolved with a failure, the specified Function is applied to this Promise to produce a recovery value.

        • If the recovery value is not null, the returned Promise must be resolved with the recovery value.
        • If the recovery value is null, the returned Promise must be failed with the failure of this Promise.
        • If the specified Function throws an exception, the returned Promise must be failed with that exception.

        To recover from a failure of this Promise with a recovery value of null, the Promise.recoverWith(Function) method must be used. The specified Function for Promise.recoverWith(Function) can return Promises.resolved(null) to supply the desired null value.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        recover in interface Promise<T>
        Parameters:
        recovery - If this Promise resolves with a failure, the specified Function is called to produce a recovery value to be used to resolve the returned Promise. Must not be null.
        Returns:
        A Promise that resolves with the value of this Promise or recovers from the failure of this Promise.
      • recoverWith

        public Promise<T> recoverWith​(Function<Promise<?>,​Promise<? extends T>> recovery)
        Recover from a failure of this Promise with a recovery Promise.

        If this Promise is successfully resolved, the returned Promise must be resolved with the value of this Promise.

        If this Promise is resolved with a failure, the specified Function is applied to this Promise to produce a recovery Promise.

        • If the recovery Promise is not null, the returned Promise must be resolved with the recovery Promise.
        • If the recovery Promise is null, the returned Promise must be failed with the failure of this Promise.
        • If the specified Function throws an exception, the returned Promise must be failed with that exception.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        recoverWith in interface Promise<T>
        Parameters:
        recovery - If this Promise resolves with a failure, the specified Function is called to produce a recovery Promise to be used to resolve the returned Promise. Must not be null.
        Returns:
        A Promise that resolves with the value of this Promise or recovers from the failure of this Promise.
      • fallbackTo

        public Promise<T> fallbackTo​(Promise<? extends T> fallback)
        Fall back to the value of the specified Promise if this Promise fails.

        If this Promise is successfully resolved, the returned Promise must be resolved with the value of this Promise.

        If this Promise is resolved with a failure, the successful result of the specified Promise is used to resolve the returned Promise. If the specified Promise is resolved with a failure, the returned Promise must be failed with the failure of this Promise rather than the failure of the specified Promise.

        This method may be called at any time including before and after this Promise has been resolved.

        Specified by:
        fallbackTo in interface Promise<T>
        Parameters:
        fallback - The Promise whose value must be used to resolve the returned Promise if this Promise resolves with a failure. Must not be null.
        Returns:
        A Promise that returns the value of this Promise or falls back to the value of the specified Promise.
      • timeout

        public Promise<T> timeout​(long millis)
        Time out the resolution of this Promise.

        If this Promise is successfully resolved before the timeout, the returned Promise is resolved with the value of this Promise. If this Promise is resolved with a failure before the timeout, the returned Promise is resolved with the failure of this Promise. If the timeout is reached before this Promise is resolved, the returned Promise is failed with a TimeoutException.

        Specified by:
        timeout in interface Promise<T>
        Parameters:
        millis - The time to wait in milliseconds. Zero and negative time is treated as an immediate timeout.
        Returns:
        A Promise that is resolved when either this Promise is resolved or the specified timeout is reached.
      • delay

        public Promise<T> delay​(long millis)
        Delay after the resolution of this Promise.

        Once this Promise is resolved, resolve the returned Promise with this Promise after the specified delay.

        Specified by:
        delay in interface Promise<T>
        Parameters:
        millis - The time to delay in milliseconds. Zero and negative time is treated as no delay.
        Returns:
        A Promise that is resolved with this Promise after this Promise is resolved and the specified delay has elapsed.
      • collect

        abstract PromiseImpl.Result<T> collect()
        Return a holder of the result of this PromiseImpl.
        Since:
        1.1
      • collect

        static <R> PromiseImpl.Result<R> collect​(Promise<? extends R> promise)
        Return a holder of the result of the specified Promise.
        Since:
        1.1