Package org.cometd.bayeux
Interface Promise<C>
- Type Parameters:
C- the type of the result value
- All Known Implementing Classes:
Promise.Completable
public interface Promise<C>
The future result of an operation, either a value if the operation succeeded, or a failure if the operation failed.
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Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic classA CompletableFuture that is also a Promise. -
Field Summary
Fields -
Method Summary
Modifier and TypeMethodDescriptiondefault BiConsumer<C,Throwable> complete()Returns aBiConsumerthat, when invoked, completes this Promise.static <T> Promise<T>complete(BiConsumer<T, Throwable> fn) Returns a Promise that, when completed, invokes the givenBiConsumerfunction.default voidCallback to invoke when the operation fails.static <T> Promise<T>static <T> Promise<T>noop()default voidCallback to invoke when the operation succeeds.
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Field Details
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NOOP
Shared instance whose methods are implemented empty,
use
noop()to ease type inference.
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Method Details
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succeed
Callback to invoke when the operation succeeds.
- Parameters:
result- the result- See Also:
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fail
Callback to invoke when the operation fails.
- Parameters:
failure- the operation failure
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complete
Returns a
BiConsumerthat, when invoked, completes this Promise.Typical usage is with
CompletableFuture:public void process(ServerMessage message, Promise<Boolean> promise) { CompletableFuture.supplyAsync(() -> asyncOperation(message)) .whenComplete(promise.complete()); }- Returns:
- a BiConsumer that completes this Promise
- See Also:
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noop
- Type Parameters:
T- the type of the empty result- Returns:
- a Promise whose methods are implemented empty.
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from
- Type Parameters:
T- the type of the result value- Parameters:
succeed- the Consumer to call in case of successful completionfail- the Consumer to call in case of failed completion- Returns:
- a Promise from the given consumers
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complete
Returns a Promise that, when completed, invokes the given
BiConsumerfunction.- Type Parameters:
T- the type of the result value- Parameters:
fn- the function to invoke when the Promise is completed- Returns:
- a Promise that invokes the BiConsumer function
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