T
- The result type associated with the Promise.abstract class PromiseImpl<T> extends java.lang.Object implements Promise<T>
This class is not used directly by clients. Clients should use
PromiseFactory
to create a Promise
.
Modifier and Type | Class and Description |
---|---|
private class |
PromiseImpl.OnFailure
A callback used for the
onFailure(Consumer) method. |
private class |
PromiseImpl.OnSuccess
A callback used for the
onSuccess(Consumer) method. |
(package private) static class |
PromiseImpl.Result<P>
A holder of the result of a Promise.
|
Modifier and Type | Field and Description |
---|---|
private 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.
|
private PromiseFactory |
factory
The factory to use for callbacks and scheduled operations.
|
Constructor and Description |
---|
PromiseImpl(PromiseFactory factory)
Initialize this Promise.
|
Modifier and Type | Method and Description |
---|---|
(package private) static <V> void |
chain(Promise<V> promise,
java.lang.Runnable chain)
Run the specified chain when the specified promise is resolved.
|
(package private) abstract PromiseImpl.Result<T> |
collect()
Return a holder of the result of this PromiseImpl.
|
(package private) static <R> PromiseImpl.Result<R> |
collect(Promise<? extends R> promise)
Return a holder of the result of the specified Promise.
|
(package private) <V> DeferredPromiseImpl<V> |
deferred()
Return a new
DeferredPromiseImpl using the PromiseFactory
of this PromiseImpl. |
Promise<T> |
delay(long millis)
Delay after the resolution of this Promise.
|
(package private) <V> FailedPromiseImpl<V> |
failed(java.lang.Throwable f)
Return a new
FailedPromiseImpl using the PromiseFactory
of this PromiseImpl. |
Promise<T> |
fallbackTo(Promise<? extends T> fallback)
Fall back to the value of the specified Promise if this Promise fails.
|
Promise<T> |
filter(Predicate<? super T> predicate)
Filter the value of this Promise.
|
<R> Promise<R> |
flatMap(Function<? super T,Promise<? extends R>> mapper)
FlatMap the value of this Promise.
|
<R> Promise<R> |
map(Function<? super T,? extends R> mapper)
Map the value of this Promise.
|
(package private) void |
notifyCallbacks()
Call any registered callbacks if this Promise is resolved.
|
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.
|
Promise<T> |
onResolve(java.lang.Runnable callback)
Register a callback to be called when this Promise is resolved.
|
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.
|
Promise<T> |
recover(Function<Promise<?>,? extends T> recovery)
Recover from a failure of this Promise with a recovery value.
|
Promise<T> |
recoverWith(Function<Promise<?>,Promise<? extends T>> recovery)
Recover from a failure of this Promise with a recovery Promise.
|
(package private) <V> ResolvedPromiseImpl<V> |
resolved(V v)
Return a new
ResolvedPromiseImpl using the PromiseFactory
of this PromiseImpl. |
(package private) java.util.concurrent.ScheduledFuture<?> |
schedule(java.lang.Runnable operation,
long delay,
java.util.concurrent.TimeUnit unit)
Schedule a operation on the scheduled executor.
|
<R> Promise<R> |
then(Success<? super T,? extends R> success)
Chain a new Promise to this Promise with a Success callback.
|
<R> Promise<R> |
then(Success<? super T,? extends R> success,
Failure failure)
Chain a new Promise to this Promise with Success and Failure callbacks.
|
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.
|
Promise<T> |
timeout(long millis)
Time out the resolution of this Promise.
|
(package private) static void |
uncaughtException(java.lang.Throwable t)
Handle an uncaught exception from a Runnable.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getFailure, getValue, isDone
private final PromiseFactory factory
private final java.util.concurrent.ConcurrentLinkedQueue<java.lang.Runnable> callbacks
PromiseImpl(PromiseFactory factory)
factory
- The factory to use for callbacks and scheduled
operations.<V> DeferredPromiseImpl<V> deferred()
DeferredPromiseImpl
using the PromiseFactory
of this PromiseImpl.<V> ResolvedPromiseImpl<V> resolved(V v)
ResolvedPromiseImpl
using the PromiseFactory
of this PromiseImpl.v
- Value for the ResolvedPromiseImpl.<V> FailedPromiseImpl<V> failed(java.lang.Throwable f)
FailedPromiseImpl
using the PromiseFactory
of this PromiseImpl.f
- Failure for the FailedPromiseImpl.public Promise<T> onResolve(java.lang.Runnable callback)
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.
void notifyCallbacks()
java.util.concurrent.ScheduledFuture<?> schedule(java.lang.Runnable operation, long delay, java.util.concurrent.TimeUnit unit)
static void uncaughtException(java.lang.Throwable t)
t
- The uncaught exception.static <V> void chain(Promise<V> promise, java.lang.Runnable chain)
promise
- The promise associated with the chain.chain
- The chain to run when the promise is resolved.public Promise<T> onSuccess(Consumer<? super T> success)
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.
public Promise<T> onFailure(Consumer<? super java.lang.Throwable> 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.
public <R> Promise<R> then(Success<? super T,? extends R> success, Failure failure)
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.
then
in interface Promise<T>
R
- The value type associated with the returned Promise.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.public <R> Promise<R> then(Success<? super T,? extends R> success)
This method performs the same function as calling
Promise.then(Success, Failure)
with the specified Success callback and
null
for the Failure callback.
then
in interface Promise<T>
R
- The value type associated with the returned Promise.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.Promise.then(Success, Failure)
public Promise<T> thenAccept(Consumer<? super T> consumer)
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.
thenAccept
in interface Promise<T>
consumer
- The Consumer callback that receives the value of this
Promise. Must not be null
.public Promise<T> filter(Predicate<? super T> predicate)
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.
public <R> Promise<R> map(Function<? super T,? extends R> mapper)
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.
map
in interface Promise<T>
R
- The value type associated with the returned Promise.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
.public <R> Promise<R> flatMap(Function<? super T,Promise<? extends R>> mapper)
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.
flatMap
in interface Promise<T>
R
- The value type associated with the returned Promise.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
.public Promise<T> recover(Function<Promise<?>,? extends T> recovery)
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.
null
, the returned Promise must
be resolved with the recovery value.null
, the returned Promise must be
failed with the failure of this Promise.
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.
recover
in interface Promise<T>
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
.public Promise<T> recoverWith(Function<Promise<?>,Promise<? extends T>> recovery)
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.
null
, the returned Promise
must be resolved with the recovery Promise.null
, the returned Promise must be
failed with the failure of this Promise.This method may be called at any time including before and after this Promise has been resolved.
recoverWith
in interface Promise<T>
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
.public Promise<T> fallbackTo(Promise<? extends T> fallback)
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.
fallbackTo
in interface Promise<T>
fallback
- The Promise whose value must be used to resolve the
returned Promise if this Promise resolves with a failure. Must not
be null
.public Promise<T> timeout(long millis)
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
.
public Promise<T> delay(long millis)
Once this Promise is resolved, resolve the returned Promise with this Promise after the specified delay.
abstract PromiseImpl.Result<T> collect()
static <R> PromiseImpl.Result<R> collect(Promise<? extends R> promise)