Interface Subscription

Functional Interface:: This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface public interface Subscription

Represents a cancel or cleanup operation for an action that can be cancelled or that allocated resources. Subscriptions can be obtained, for example, as a result of registering a callback, starting a timer, or allocating resources. They provide a convenient way for subscribers to cancel these actions at a later time, without requiring additional information or even access to the source from where they were originally obtained.

 class Publisher {
   public Subscription subscribe(Consumer<NewsLetter> subscriber) {
     register(subscriber);

     // return a Subscription which unregisters the original subscriber
     return () -> unregister(subscriber);
   }
 }

Subscriptions can also be combined using combine(javafx.util.Subscription...) and and(javafx.util.Subscription), which allows for multiple subscriptions to be unsubscribed together. This is useful when they share the same lifecycle, for example, when performing cleanup for the same object.

Since:: 21

Field Summary

Modifier and Type	Field	Description
`static final Subscription`	`EMPTY`	An empty subscription.

Method Summary

Modifier and Type	Method	Description
`default Subscription`	`and(Subscription other)`	Combines this `Subscription` with the given `Subscription` and returns a new `Subscription` which will cancel both when cancelled.
`static Subscription`	`combine(Subscription... subscriptions)`	Returns a `Subscription` which combines all of the given subscriptions.
`void`	`unsubscribe()`	Cancels this subscription, or does nothing if already cancelled.

Field Details

EMPTY

static final Subscription EMPTY

An empty subscription. Does nothing when cancelled.

Method Details

combine

static Subscription combine(Subscription... subscriptions)

Returns a Subscription which combines all of the given subscriptions.

Parameters:: subscriptions - an array of subscriptions to combine, cannot be null or contain null
Returns:: a Subscription, never null
Throws:: NullPointerException - when subscriptions is null or contains null

unsubscribe

void unsubscribe()

Cancels this subscription, or does nothing if already cancelled.

Implementation Requirements:: Implementors must ensure the implementation is idempotent (a no-op if called more than once).

and

default Subscription and(Subscription other)

Combines this Subscription with the given Subscription and returns a new Subscription which will cancel both when cancelled.

This is equivalent to Subscription.combine(this, other).

Parameters:: other - another Subscription, cannot be null
Returns:: a combined Subscription which will cancel both when cancelled, never null
Throws:: NullPointerException - when other is null

© 2008, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from JavaFX API Documentation.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Java, JavaFX and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.