public abstract class

DisposableSubscriber

extends Object
implements FlowableSubscriber<T> Disposable
java.lang.Object
   ↳ io.reactivex.subscribers.DisposableSubscriber<T>

Class Overview

An abstract Subscriber that allows asynchronous, external cancellation by implementing Disposable.

All pre-implemented final methods are thread-safe.

The default onStart() requests Long.MAX_VALUE by default. Override the method to request a custom positive amount. Use the protected request(long) to request more items and cancel() to cancel the sequence from within an onNext implementation.

Note that calling request(long) from onStart() may trigger an immediate, asynchronous emission of data to onNext(Object). Make sure all initialization happens before the call to request() in onStart(). Calling request(long) inside onNext(Object) can happen at any time because by design, onNext calls from upstream are non-reentrant and non-overlapping.

Like all other consumers, DisposableSubscriber can be subscribed only once. Any subsequent attempt to subscribe it to a new source will yield an IllegalStateException with message "It is not allowed to subscribe with a(n) <class name> multiple times.".

Implementation of onStart(), onNext(Object), onError(Throwable) and onComplete() are not allowed to throw any unchecked exceptions. If for some reason this can't be avoided, use safeSubscribe(org.reactivestreams.Subscriber) instead of the standard subscribe() method.

Example


 Disposable d =
     Flowable.range(1, 5)
     .subscribeWith(new DisposableSubscriber<Integer>() {
         @Override public void onStart() {
             request(1);
         }
         @Override public void onNext(Integer t) {
             if (t == 3) {
                 cancel();
             }
             System.out.println(t);
             request(1);
         }
         @Override public void onError(Throwable t) {
             t.printStackTrace();
         }
         @Override public void onComplete() {
             System.out.println("Done!");
         }
     });
 // ...
 d.dispose();
 

Summary

Public Constructors
DisposableSubscriber()
Public Methods
final void dispose()
Dispose the resource, the operation should be idempotent.
final boolean isDisposed()
Returns true if this resource has been disposed.
final void onSubscribe(Subscription s)
Implementors of this method should make sure everything that needs to be visible in onNext(Object) is established before calling request(long).
Protected Methods
final void cancel()
Cancels the Subscription set via onSubscribe or makes sure a Subscription set asynchronously (later) is cancelled immediately.
void onStart()
Called once the single upstream Subscription is set via onSubscribe.
final void request(long n)
Requests the specified amount from the upstream if its Subscription is set via onSubscribe already.
[Expand]
Inherited Methods
From class java.lang.Object
From interface io.reactivex.FlowableSubscriber
From interface io.reactivex.disposables.Disposable
From interface org.reactivestreams.Subscriber

Public Constructors

public DisposableSubscriber ()

Public Methods

public final void dispose ()

Dispose the resource, the operation should be idempotent.

public final boolean isDisposed ()

Returns true if this resource has been disposed.

Returns
  • true if this resource has been disposed

public final void onSubscribe (Subscription s)

Implementors of this method should make sure everything that needs to be visible in onNext(Object) is established before calling request(long). In practice this means no initialization should happen after the request() call and additional behavior is thread safe in respect to onNext.

Protected Methods

protected final void cancel ()

Cancels the Subscription set via onSubscribe or makes sure a Subscription set asynchronously (later) is cancelled immediately.

This method is thread-safe and can be exposed as a public API.

protected void onStart ()

Called once the single upstream Subscription is set via onSubscribe.

protected final void request (long n)

Requests the specified amount from the upstream if its Subscription is set via onSubscribe already.

Note that calling this method before a Subscription is set via onSubscribe leads to NullPointerException and meant to be called from inside onStart or onNext.

Parameters
n the request amount, positive