Package org.forgerock.util.promise

Class PromiseImpl<V,E extends Exception>

java.lang.Object
org.forgerock.util.promise.PromiseImpl<V,E>
Type Parameters:
V - The type of the task's result, or Void if the task does not return anything (i.e. it only has side-effects).
E - The type of the exception thrown by the task if it fails, or NeverThrowsException if the task cannot fail.
All Implemented Interfaces:
ExceptionHandler<E>, Promise<V,E>, ResultHandler<V>, RuntimeExceptionHandler
public class PromiseImpl<V,E extends Exception> extends Object implements Promise<V,E>, ResultHandler<V>, ExceptionHandler<E>, RuntimeExceptionHandler
An implementation of Promise which can be used as is, or as the basis for more complex asynchronous behavior. A PromiseImpl must be completed by invoking one of:
  • handleResult(V) - marks the promise as having succeeded with the provide result
  • handleException(E) - marks the promise as having failed with the provided exception
  • cancel(boolean) - requests cancellation of the asynchronous task represented by the promise. Cancellation is only supported if the tryCancel(boolean) is overridden and returns an exception.
See Also:

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    PromiseImpl()
    Creates a new pending Promise implementation.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    cancel(boolean mayInterruptIfRunning)
    Attempts to cancel the asynchronous task associated with this Promise.
    static <V, E extends Exception>
    PromiseImpl<V,E>
    create()
    Creates a new pending Promise implementation.
    final V
    get()
    Waits if necessary for this Promise to complete, and then returns the result if it completed successfully, or throws an ExecutionException containing the cause of the failure.
    final V
    get(long timeout, TimeUnit unit)
    Waits if necessary for at most the given time for this Promise to complete, and then returns the result if it completed successfully, or throws an ExecutionException containing the cause of the failure.
    final V
    getOrThrow()
    Waits if necessary for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.
    final V
    getOrThrow(long timeout, TimeUnit unit)
    Waits if necessary for at most the given time for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.
    final V
    getOrThrowUninterruptibly()
    Deprecated.
    final V
    getOrThrowUninterruptibly(long timeout, TimeUnit unit)
    Deprecated.
    final void
    handleException(E exception)
    Signals that the asynchronous task represented by this promise has failed.
    final void
    handleResult(V result)
    Signals that the asynchronous task represented by this promise has succeeded.
    void
    handleRuntimeException(RuntimeException exception)
    Invoked when the asynchronous task has failed with a runtime exception.
    final boolean
    isCancelled()
    Returns true if this Promise was cancelled before it completed normally.
    final boolean
    isDone()
    Returns true if this Promise has completed.
    final boolean
    isResult()
    Returns true if this Promise has completed and contains a value.
    final <VOUT> Promise<VOUT,E>
    then(Function<? super V,VOUT,E> onResult)
    Submits the provided function for execution once this Promise has completed with a result, and returns a new Promise representing the outcome of the function.
    final <VOUT, EOUT extends Exception>
    Promise<VOUT,EOUT>
    then(Function<? super V,VOUT,EOUT> onResult, Function<? super E,VOUT,EOUT> onException)
    Submits the provided functions for execution once this Promise has completed (with a result or an exception), and returns a new Promise representing the outcome of the invoked function.
    final <VOUT, EOUT extends Exception>
    Promise<VOUT,EOUT>
    then(Function<? super V,VOUT,EOUT> onResult, Function<? super E,VOUT,EOUT> onException, Function<? super RuntimeException,VOUT,EOUT> onRuntimeException)
    Submits the provided functions for execution once this Promise has completed (with a result or an exception or a RuntimeException), and returns a new Promise representing the outcome of the invoked function.
    final Promise<V,E>
    thenAlways(Runnable always)
    Submits the provided runnable for execution once this Promise has completed, and regardless of whether it has a result or an exception.
    final <VOUT> Promise<VOUT,E>
    thenAsync(AsyncFunction<? super V,VOUT,E> onResult)
    Submits the provided asynchronous function for execution once this Promise has completed with a result, and returns a new Promise representing the outcome of the function.
    final <VOUT, EOUT extends Exception>
    Promise<VOUT,EOUT>
    thenAsync(AsyncFunction<? super V,VOUT,EOUT> onResult, AsyncFunction<? super E,VOUT,EOUT> onException)
    Submits the provided asynchronous functions for execution once this Promise has completed, and returns a new Promise representing the outcome of the invoked function.
    final <VOUT, EOUT extends Exception>
    Promise<VOUT,EOUT>
    thenAsync(AsyncFunction<? super V,VOUT,EOUT> onResult, AsyncFunction<? super E,VOUT,EOUT> onException, AsyncFunction<? super RuntimeException,VOUT,EOUT> onRuntimeException)
    Submits the provided asynchronous functions for execution once this Promise has completed, and returns a new Promise representing the outcome of the invoked function.
    <EOUT extends Exception>
    Promise<V,EOUT>
    thenCatch(Function<? super E,V,EOUT> onException)
    Submits the provided function for execution once this Promise has not completed with a result (has completed with an exception), and returns a new Promise representing the outcome of the function.
    final <EOUT extends Exception>
    Promise<V,EOUT>
    thenCatchAsync(AsyncFunction<? super E,V,EOUT> onException)
    Submits the provided asynchronous function for execution once this Promise has completed with an exception, and returns a new Promise representing the outcome of the function.
    Promise<V,E>
    thenCatchRuntimeException(Function<? super RuntimeException,V,E> onRuntimeException)
    Submits the provided function for execution once this Promise has not completed with a result nor with an exception but with a RuntimeException, and returns a new Promise representing the outcome of the function.
    final Promise<V,E>
    thenCatchRuntimeExceptionAsync(AsyncFunction<? super RuntimeException,V,E> onRuntimeException)
    Submits the provided asynchronous function for execution once this Promise has completed with a RuntimeException, and returns a new Promise representing the outcome of the function.
    final Promise<V,E>
    thenFinally(Runnable onFinally)
    Submits the provided runnable for execution once this Promise has completed, and regardless of whether of its outcome.
    final <T extends ResultHandler<? super V> & ExceptionHandler<? super E> & RuntimeExceptionHandler>
    Promise<V,E>
    thenOnCompletion(T handler)
    Registers the provided completion handler for notification for all completion cases of this Promise.
    final Promise<V,E>
    thenOnException(ExceptionHandler<? super E> onException)
    Registers the provided completion handler for notification if this Promise cannot be completed due to an exception.
    final Promise<V,E>
    thenOnResult(ResultHandler<? super V> onResult)
    Registers the provided completion handler for notification once this Promise has completed with a result.
    final Promise<V,E>
    thenOnResultOrException(Runnable onResultOrException)
    Submits the provided runnable for execution once this Promise has completed, and regardless of whether it has a result or an exception.
    final Promise<V,E>
    thenOnResultOrException(ResultHandler<? super V> onResult, ExceptionHandler<? super E> onException)
    Registers the provided completion handlers for notification once this Promise has completed (with a result or an exception).
    final Promise<V,E>
    thenOnRuntimeException(RuntimeExceptionHandler onRuntimeException)
    Registers the provided completion handler for notification if this Promise cannot be completed due to an runtime exception.
    protected E
    tryCancel(boolean mayInterruptIfRunning)
    Invoked when the client attempts to cancel the asynchronous task represented by this promise.
    final boolean
    tryHandleException(E exception)
    Attempts to signal that the asynchronous task represented by this promise has failed.
    final boolean
    tryHandleResult(V result)
    Attempts to signal that the asynchronous task represented by this promise has succeeded.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface org.forgerock.util.promise.Promise

    getOrThrowIfInterrupted, thenDiscardResult

  • Constructor Details

    • PromiseImpl

      protected PromiseImpl()
      Creates a new pending Promise implementation. This constructor is protected to allow for sub-classing.

  • Method Details

    • create

      public static <V, E extends Exception> PromiseImpl<V,E> create()
      Creates a new pending Promise implementation.
      Type Parameters:
      V - The type of the task's result, or Void if the task does not return anything (i.e. it only has side-effects).
      E - The type of the exception thrown by the task if it fails, or NeverThrowsException if the task cannot fail.
      Returns:
      A new pending Promise implementation.

    • cancel

      public final boolean cancel(boolean mayInterruptIfRunning)
      Description copied from interface: Promise
      Attempts to cancel the asynchronous task associated with this Promise. Cancellation will fail if this Promise has already completed or has already been cancelled. If successful, then cancellation will complete this Promise with an appropriate exception and notify any registered functions and completion handlers.

      After this method returns, subsequent calls to Promise.isDone() will always return true. Subsequent calls to Promise.isCancelled() will always return true if this method returned true.

      Specified by:
      cancel in interface Promise<V,E extends Exception>
      Parameters:
      mayInterruptIfRunning - true if the thread executing executing the response handler should be interrupted; otherwise, in-progress response handlers are allowed to complete.
      Returns:
      false if Promise could not be cancelled, typically because it has already completed normally; true otherwise.

    • get

      public final V get() throws InterruptedException, ExecutionException
      Description copied from interface: Promise
      Waits if necessary for this Promise to complete, and then returns the result if it completed successfully, or throws an ExecutionException containing the cause of the failure.
      Specified by:
      get in interface Promise<V,E extends Exception>
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      InterruptedException - If the current thread was interrupted while waiting.
      ExecutionException - If this Promise was cancelled or did not complete successfully. The ExecutionException will contain the cause of the failure.

    • get

      public final V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException
      Description copied from interface: Promise
      Waits if necessary for at most the given time for this Promise to complete, and then returns the result if it completed successfully, or throws an ExecutionException containing the cause of the failure.
      Specified by:
      get in interface Promise<V,E extends Exception>
      Parameters:
      timeout - The maximum time to wait.
      unit - The time unit of the timeout argument.
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      InterruptedException - If the current thread was interrupted while waiting.
      ExecutionException - If this Promise was cancelled or did not complete successfully. The ExecutionException will contain the cause of the failure.
      TimeoutException - If the wait timed out.

    • getOrThrow

      public final V getOrThrow() throws InterruptedException, E
      Description copied from interface: Promise
      Waits if necessary for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.
      Specified by:
      getOrThrow in interface Promise<V,E extends Exception>
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      InterruptedException - If the current thread was interrupted while waiting.
      E - If this Promise was cancelled or did not complete successfully.

    • getOrThrow

      public final V getOrThrow(long timeout, TimeUnit unit) throws InterruptedException, E, TimeoutException
      Description copied from interface: Promise
      Waits if necessary for at most the given time for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.
      Specified by:
      getOrThrow in interface Promise<V,E extends Exception>
      Parameters:
      timeout - The maximum time to wait.
      unit - The time unit of the timeout argument.
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      InterruptedException - If the current thread was interrupted while waiting.
      E - If this Promise was cancelled or did not complete successfully.
      TimeoutException - If the wait timed out.

    • getOrThrowUninterruptibly

      @Deprecated public final V getOrThrowUninterruptibly() throws E
      Deprecated.
      Description copied from interface: Promise
      Waits if necessary for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.

      This method is similar to Promise.getOrThrow() except that it will ignore thread interrupts. When this method returns the status of the current thread will be interrupted if an interrupt was received while waiting.

      Specified by:
      getOrThrowUninterruptibly in interface Promise<V,E extends Exception>
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      E - If this Promise was cancelled or did not complete successfully.

    • getOrThrowUninterruptibly

      @Deprecated public final V getOrThrowUninterruptibly(long timeout, TimeUnit unit) throws E, TimeoutException
      Deprecated.
      Description copied from interface: Promise
      Waits if necessary for at most the given time for this Promise to complete, and then returns the result if it completed successfully, or throws an exception representing the cause of the failure.

      This method is similar to Promise.getOrThrow(long, TimeUnit) except that it will ignore thread interrupts. When this method returns the status of the current thread will be interrupted if an interrupt was received while waiting.

      Specified by:
      getOrThrowUninterruptibly in interface Promise<V,E extends Exception>
      Parameters:
      timeout - The maximum time to wait.
      unit - The time unit of the timeout argument.
      Returns:
      The result, but only if this Promise completed successfully.
      Throws:
      E - If this Promise was cancelled or did not complete successfully.
      TimeoutException - If the wait timed out.

    • handleException

      public final void handleException(E exception)
      Signals that the asynchronous task represented by this promise has failed. If the task has already completed (i.e. isDone() == true) then calling this method has no effect and the provided result will be discarded.
      Specified by:
      handleException in interface ExceptionHandler<V>
      Parameters:
      exception - The exception indicating why the task failed.
      See Also:

    • handleRuntimeException

      public void handleRuntimeException(RuntimeException exception)
      Description copied from interface: RuntimeExceptionHandler
      Invoked when the asynchronous task has failed with a runtime exception.
      Specified by:
      handleRuntimeException in interface RuntimeExceptionHandler
      Parameters:
      exception - The runtime exception indicating why the asynchronous task has failed.

    • handleResult

      public final void handleResult(V result)
      Signals that the asynchronous task represented by this promise has succeeded. If the task has already completed (i.e. isDone() == true) then calling this method has no effect and the provided result will be discarded.
      Specified by:
      handleResult in interface ResultHandler<V>
      Parameters:
      result - The result of the asynchronous task (may be null).
      See Also:

    • tryHandleException

      public final boolean tryHandleException(E exception)
      Attempts to signal that the asynchronous task represented by this promise has failed. If the task has already completed (i.e. isDone() == true) then calling this method has no effect and false is returned.

      This method should be used in cases where multiple threads may concurrently attempt to complete a promise and need to release resources if the completion attempt fails. For example, an asynchronous TCP connect attempt may complete after a timeout has expired. In this case the connection should be immediately closed because it is never going to be used.

      Parameters:
      exception - The exception indicating why the task failed.
      Returns:
      false if this promise has already been completed, either due to normal termination, an exception, or cancellation (i.e. isDone() == true).
      See Also:

    • tryHandleResult

      public final boolean tryHandleResult(V result)
      Attempts to signal that the asynchronous task represented by this promise has succeeded. If the task has already completed (i.e. isDone() == true) then calling this method has no effect and false is returned.

      This method should be used in cases where multiple threads may concurrently attempt to complete a promise and need to release resources if the completion attempt fails. For example, an asynchronous TCP connect attempt may complete after a timeout has expired. In this case the connection should be immediately closed because it is never going to be used.

      Parameters:
      result - The result of the asynchronous task (may be null).
      Returns:
      false if this promise has already been completed, either due to normal termination, an exception, or cancellation (i.e. isDone() == true).
      See Also:

    • isCancelled

      public final boolean isCancelled()
      Description copied from interface: Promise
      Returns true if this Promise was cancelled before it completed normally.
      Specified by:
      isCancelled in interface Promise<V,E extends Exception>
      Returns:
      true if this Promise was cancelled before it completed normally, otherwise false.

    • isDone

      public final boolean isDone()
      Description copied from interface: Promise
      Returns true if this Promise has completed.

      Completion may be due to normal termination, an exception, or cancellation. In all of these cases, this method will return true.

      Specified by:
      isDone in interface Promise<V,E extends Exception>
      Returns:
      true if this Promise has completed, otherwise false.

    • isResult

      public final boolean isResult()
      Description copied from interface: Promise
      Returns true if this Promise has completed and contains a value.
      Specified by:
      isResult in interface Promise<V,E extends Exception>
      Returns:
      true if this Promise has completed with a value.

    • thenOnException

      public final Promise<V,E> thenOnException(ExceptionHandler<? super E> onException)
      Description copied from interface: Promise
      Registers the provided completion handler for notification if this Promise cannot be completed due to an exception. If this Promise completes with a result then the completion handler will not be notified.

      This method can be used for asynchronous completion notification.

      Specified by:
      thenOnException in interface Promise<V,E extends Exception>
      Parameters:
      onException - The completion handler which will be notified upon failure completion of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • thenOnResult

      public final Promise<V,E> thenOnResult(ResultHandler<? super V> onResult)
      Description copied from interface: Promise
      Registers the provided completion handler for notification once this Promise has completed with a result. If this Promise completes with an exception then the completion handler will not be notified.

      This method can be used for asynchronous completion notification and is equivalent to Promise.then(Function).

      Specified by:
      thenOnResult in interface Promise<V,E extends Exception>
      Parameters:
      onResult - The completion handler which will be notified upon successful completion of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • thenOnResultOrException

      public final Promise<V,E> thenOnResultOrException(ResultHandler<? super V> onResult, ExceptionHandler<? super E> onException)
      Description copied from interface: Promise
      Registers the provided completion handlers for notification once this Promise has completed (with a result or an exception). If this Promise completes with a result then onResult will be notified with the result, otherwise onException will be notified with the exception that occurred.

      This method can be used for asynchronous completion notification.

      Specified by:
      thenOnResultOrException in interface Promise<V,E extends Exception>
      Parameters:
      onResult - The completion handler which will be notified upon completion with a result of this Promise.
      onException - The completion handler which will be notified upon failure of this Promise.
      Returns:
      A Promise that is guaranted to be completed once the provided callback has been executed.

    • thenOnResultOrException

      public final Promise<V,E> thenOnResultOrException(Runnable onResultOrException)
      Description copied from interface: Promise
      Submits the provided runnable for execution once this Promise has completed, and regardless of whether it has a result or an exception.

      This method can be used for resource cleanup after a series of asynchronous tasks have completed. More specifically, this method should be used in a similar manner to finally statements in try...catch expressions.

      This method is equivalent to Promise.thenAlways(Runnable).

      Specified by:
      thenOnResultOrException in interface Promise<V,E extends Exception>
      Parameters:
      onResultOrException - The runnable which will be notified regardless of the final outcome of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • then

      public final <VOUT> Promise<VOUT,E> then(Function<? super V,VOUT,E> onResult)
      Description copied from interface: Promise
      Submits the provided function for execution once this Promise has completed with a result, and returns a new Promise representing the outcome of the function. If this Promise does not complete with a result then the function will not be invoked and the exception will be forwarded to the returned Promise.

      This method can be used for transforming the result of an asynchronous task.

      Specified by:
      then in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the function's result, or Void if the function does not return anything (i.e. it only has side-effects). Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The function which will be executed upon successful completion of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • thenCatch

      public <EOUT extends Exception> Promise<V,EOUT> thenCatch(Function<? super E,V,EOUT> onException)
      Description copied from interface: Promise
      Submits the provided function for execution once this Promise has not completed with a result (has completed with an exception), and returns a new Promise representing the outcome of the function. If this Promise completes with a result then the function will not be invoked and the result notification will be forwarded to the returned Promise.

      This method can be used for transforming the result of an asynchronous task.

      Specified by:
      thenCatch in interface Promise<V,E extends Exception>
      Type Parameters:
      EOUT - The type of the exception thrown by the function if it fails, or NeverThrowsException if it cannot fails. Note that the type may be different to the type of this Promise.
      Parameters:
      onException - The function which will be executed upon failure completion of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • thenCatchRuntimeException

      public Promise<V,E> thenCatchRuntimeException(Function<? super RuntimeException,V,E> onRuntimeException)
      Description copied from interface: Promise
      Submits the provided function for execution once this Promise has not completed with a result nor with an exception but with a RuntimeException, and returns a new Promise representing the outcome of the function. If this Promise completes with a result or an exception then the function will not be invoked and the result notification will be forwarded to the returned Promise.

      This method can be used for transforming the result of an asynchronous task.

      Specified by:
      thenCatchRuntimeException in interface Promise<V,E extends Exception>
      Parameters:
      onRuntimeException - The function which will be executed upon failure completion of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • then

      public final <VOUT, EOUT extends Exception> Promise<VOUT,EOUT> then(Function<? super V,VOUT,EOUT> onResult, Function<? super E,VOUT,EOUT> onException)
      Description copied from interface: Promise
      Submits the provided functions for execution once this Promise has completed (with a result or an exception), and returns a new Promise representing the outcome of the invoked function. If this Promise completes with a result then onResult will be invoked with the result, otherwise onException will be invoked with the exception that occurred.

      This method can be used for transforming the outcome of an asynchronous task.

      Specified by:
      then in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the functions' result, or Void if the functions do not return anything (i.e. they only have side-effects). Note that the type may be different to the type of this Promise.
      EOUT - The type of the exception thrown by the functions if they fail, or NeverThrowsException if they cannot fail. Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The function which will be executed upon successful completion of this Promise.
      onException - The function which will be executed upon failure of this Promise.
      Returns:
      A new Promise representing the outcome of the invoked function.

    • then

      public final <VOUT, EOUT extends Exception> Promise<VOUT,EOUT> then(Function<? super V,VOUT,EOUT> onResult, Function<? super E,VOUT,EOUT> onException, Function<? super RuntimeException,VOUT,EOUT> onRuntimeException)
      Description copied from interface: Promise
      Submits the provided functions for execution once this Promise has completed (with a result or an exception or a RuntimeException), and returns a new Promise representing the outcome of the invoked function. If this Promise completes with a result then onResult will be invoked with the result, with a RuntimeException then onRuntimeException will be invoked with the runtime exception that occurred, otherwise onException will be invoked with the exception that occurred.

      This method can be used for transforming the outcome of an asynchronous task.

      Specified by:
      then in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the functions' result, or Void if the functions do not return anything (i.e. they only have side-effects). Note that the type may be different to the type of this Promise.
      EOUT - The type of the exception thrown by the functions if they fail, or NeverThrowsException if they cannot fail. Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The function which will be executed upon successful completion of this Promise.
      onException - The function which will be executed upon failure of this Promise.
      onRuntimeException - The function which will be executed upon failure with RuntimeException of this Promise.
      Returns:
      A new Promise representing the outcome of the invoked function.

    • thenAlways

      public final Promise<V,E> thenAlways(Runnable always)
      Description copied from interface: Promise
      Submits the provided runnable for execution once this Promise has completed, and regardless of whether it has a result or an exception.

      This method can be used for resource cleanup after a series of asynchronous tasks have completed. More specifically, this method should be used in a similar manner to finally statements in try...catch expressions.

      This method is equivalent to Promise.thenOnResultOrException(Runnable).

      Specified by:
      thenAlways in interface Promise<V,E extends Exception>
      Parameters:
      always - The runnable which will be notified regardless of the final outcome of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • thenFinally

      public final Promise<V,E> thenFinally(Runnable onFinally)
      Description copied from interface: Promise
      Submits the provided runnable for execution once this Promise has completed, and regardless of whether of its outcome.

      This method can be used for resource cleanup after a series of asynchronous tasks have completed. More specifically, this method should be used in a similar manner to finally statements in try...catch expressions.

      This method is equivalent to Promise.thenAlways(Runnable).

      Specified by:
      thenFinally in interface Promise<V,E extends Exception>
      Parameters:
      onFinally - The runnable which will be notified regardless of the final outcome of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • thenAsync

      public final <VOUT> Promise<VOUT,E> thenAsync(AsyncFunction<? super V,VOUT,E> onResult)
      Description copied from interface: Promise
      Submits the provided asynchronous function for execution once this Promise has completed with a result, and returns a new Promise representing the outcome of the function. If this Promise complete with an exception then the function will not be invoked and the error will be forwarded to the returned Promise.

      This method may be used for chaining together a series of asynchronous tasks.

      Specified by:
      thenAsync in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the function's result, or Void if the function does not return anything (i.e. it only has side-effects). Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The asynchronous function which will be executed upon successful completion of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • thenCatchAsync

      public final <EOUT extends Exception> Promise<V,EOUT> thenCatchAsync(AsyncFunction<? super E,V,EOUT> onException)
      Description copied from interface: Promise
      Submits the provided asynchronous function for execution once this Promise has completed with an exception, and returns a new Promise representing the outcome of the function. If this Promise completes with a result then the function will not be invoked and the exception will be forwarded to the returned Promise.

      This method may be used for chaining together a series of asynchronous tasks.

      Specified by:
      thenCatchAsync in interface Promise<V,E extends Exception>
      Type Parameters:
      EOUT - The type of the exception thrown by the function if it fails, or NeverThrowsException if it cannot fails. Note that the type may be different to the type of this Promise.
      Parameters:
      onException - The asynchronous function which will be executed upon failure completion of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • thenCatchRuntimeExceptionAsync

      public final Promise<V,E> thenCatchRuntimeExceptionAsync(AsyncFunction<? super RuntimeException,V,E> onRuntimeException)
      Description copied from interface: Promise
      Submits the provided asynchronous function for execution once this Promise has completed with a RuntimeException, and returns a new Promise representing the outcome of the function. If this Promise completes with a result or the typed exception then the completion asynchronous function will not be called.

      This method may be used for chaining together a series of asynchronous tasks.

      Specified by:
      thenCatchRuntimeExceptionAsync in interface Promise<V,E extends Exception>
      Parameters:
      onRuntimeException - The asynchronous function which will be executed upon failure completion with a RuntimeException of this Promise.
      Returns:
      A new Promise representing the outcome of the function.

    • thenAsync

      public final <VOUT, EOUT extends Exception> Promise<VOUT,EOUT> thenAsync(AsyncFunction<? super V,VOUT,EOUT> onResult, AsyncFunction<? super E,VOUT,EOUT> onException)
      Description copied from interface: Promise
      Submits the provided asynchronous functions for execution once this Promise has completed, and returns a new Promise representing the outcome of the invoked function. If this Promise completes with a result then onResult will be invoked with the result, otherwise onException will be invoked with the exception that occurred.

      This method may be used for chaining together a series of asynchronous tasks.

      Specified by:
      thenAsync in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the functions' result, or Void if the functions do not return anything (i.e. they only have side-effects). Note that the type may be different to the type of this Promise.
      EOUT - The type of the exception thrown by the functions if they fail, or NeverThrowsException if they cannot fail. Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The asynchronous function which will be executed upon successful completion of this Promise.
      onException - The asynchronous function which will be executed upon failure of this Promise.
      Returns:
      A new Promise representing the outcome of the invoked function.

    • thenAsync

      public final <VOUT, EOUT extends Exception> Promise<VOUT,EOUT> thenAsync(AsyncFunction<? super V,VOUT,EOUT> onResult, AsyncFunction<? super E,VOUT,EOUT> onException, AsyncFunction<? super RuntimeException,VOUT,EOUT> onRuntimeException)
      Description copied from interface: Promise
      Submits the provided asynchronous functions for execution once this Promise has completed, and returns a new Promise representing the outcome of the invoked function. If this Promise completes with a result then onResult will be invoked with the result, otherwise onException will be invoked with the exception that occurred, or onRuntimeException will be invoked with the runtime exception that occurred.

      This method may be used for chaining together a series of asynchronous tasks.

      Specified by:
      thenAsync in interface Promise<V,E extends Exception>
      Type Parameters:
      VOUT - The type of the functions' result, or Void if the functions do not return anything (i.e. they only have side-effects). Note that the type may be different to the type of this Promise.
      EOUT - The type of the exception thrown by the functions if they fail, or NeverThrowsException if they cannot fail. Note that the type may be different to the type of this Promise.
      Parameters:
      onResult - The asynchronous function which will be executed upon successful completion of this Promise.
      onException - The asynchronous function which will be executed upon failure of this Promise.
      onRuntimeException - The asynchronous function which will be executed upon failure with RuntimeException of this Promise.
      Returns:
      A new Promise representing the outcome of the invoked function.

    • thenOnRuntimeException

      public final Promise<V,E> thenOnRuntimeException(RuntimeExceptionHandler onRuntimeException)
      Description copied from interface: Promise
      Registers the provided completion handler for notification if this Promise cannot be completed due to an runtime exception. If this Promise completes with a result or the typed exception then the completion handler will not be notified.

      This method can be used for asynchronous completion notification.

      Specified by:
      thenOnRuntimeException in interface Promise<V,E extends Exception>
      Parameters:
      onRuntimeException - The completion handler which will be notified upon an uncaught runtime exception completion of this Promise.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • thenOnCompletion

      public final <T extends ResultHandler<? super V> & ExceptionHandler<? super E> & RuntimeExceptionHandler> Promise<V,E> thenOnCompletion(T handler)
      Description copied from interface: Promise
      Registers the provided completion handler for notification for all completion cases of this Promise.

      This method can be used for asynchronous completion notification.

      Specified by:
      thenOnCompletion in interface Promise<V,E extends Exception>
      Type Parameters:
      T - the composite type of the handler for handling all completion cases
      Parameters:
      handler - The handler that will be called once this Promise is completed.
      Returns:
      A Promise that is guaranteed to be completed once the provided callback has been executed.

    • tryCancel

      protected E tryCancel(boolean mayInterruptIfRunning)
      Invoked when the client attempts to cancel the asynchronous task represented by this promise. Implementations which support cancellation should override this method to cancel the asynchronous task and, if successful, return an appropriate exception which can be used to signal that the task has failed.

      By default cancellation is not supported and this method returns null.

      Parameters:
      mayInterruptIfRunning - true if the thread executing this task should be interrupted; otherwise, in-progress tasks are allowed to complete.
      Returns:
      null if cancellation was not supported or not possible, otherwise an appropriate exception.