Flow.Subscription

  • Flow.Subscription manages the flow of messages between a Flow.Publisher and a Flow.Subscriber, enabling controlled message delivery and cancellation.

  • Subscribers use request(long n) to signal their demand for n additional messages, while cancel() initiates the termination of message delivery.

  • Although cancel() aims to halt message delivery, it's best-effort and subscribers might still receive some messages afterward, and termination signals like onComplete or onError are not guaranteed.

  • Requesting a non-positive number of items through request will result in an onError signal with an IllegalArgumentException.
public static interface Flow.Subscription

Message control linking a Flow.Publisher and Flow.Subscriber. Subscribers receive items only when requested, and may cancel at any time. The methods in this interface are intended to be invoked only by their Subscribers; usages in other contexts have undefined effects.

Public Method Summary

abstract void
cancel()
Causes the Subscriber to (eventually) stop receiving messages.
abstract void
request(long n)
Adds the given number n of items to the current unfulfilled demand for this subscription.

Public Methods

public abstract void cancel ()

Causes the Subscriber to (eventually) stop receiving messages. Implementation is best-effort -- additional messages may be received after invoking this method. A cancelled subscription need not ever receive an onComplete or onError signal.

public abstract void request (long n)

Adds the given number n of items to the current unfulfilled demand for this subscription. If n is less than or equal to zero, the Subscriber will receive an onError signal with an IllegalArgumentException argument. Otherwise, the Subscriber will receive up to n additional onNext invocations (or fewer if terminated).

Parameters
n the increment of demand; a value of Long.MAX_VALUE may be considered as effectively unbounded