io.reactivex.subscribers

Class DefaultSubscriber

java.lang.Object

io.reactivex.subscribers.DefaultSubscriber

Type Parameters:

T - the value type

Example

 Disposable d =
     Flowable.range(1, 5)
     .subscribeWith(new DefaultSubscriber() {
         @Override public void onStart() {
             System.out.println("Start!");
             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();
 

All Implemented Interfaces:

FlowableSubscriber, org.reactivestreams.Subscriber

public abstract class DefaultSubscriber
extends java.lang.Object
implements FlowableSubscriber

Abstract base implementation of a Subscriber with support for requesting via request(long), cancelling via via cancel() (both synchronously) and calls onStart() when the subscription happens.

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.

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

Use the protected cancel() to cancel the sequence from within an onNext implementation.

Like all other consumers, DefaultSubscriber can be subscribed only once. Any subsequent attempt to subscribe it to a new source will yield an IllegalStateException with message "Subscription already set!".

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

Constructor Summary

Constructors

Constructor and Description
DefaultSubscriber()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	cancel() Cancels the upstream's Subscription.
protected void	onStart() Called once the subscription has been set on this observer; override this to perform initialization or issue an initial request.
void	onSubscribe(org.reactivestreams.Subscription s) Implementors of this method should make sure everything that needs to be visible in Subscriber.onNext(Object) is established before calling Subscription.request(long).
protected void	request(long n) Requests from the upstream Subscription.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.reactivestreams.Subscriber

onComplete, onError, onNext

Constructor Detail

DefaultSubscriber

public DefaultSubscriber()

Method Detail

onSubscribe

public final void onSubscribe(org.reactivestreams.Subscription s)

Description copied from interface: FlowableSubscriber

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

Specified by:

onSubscribe in interface FlowableSubscriber<T>

Specified by:

onSubscribe in interface org.reactivestreams.Subscriber<T>

request

protected final void request(long n)

Requests from the upstream Subscription.

Parameters:

n - the request amount, positive

cancel

protected final void cancel()

Cancels the upstream's Subscription.

onStart

protected void onStart()

Called once the subscription has been set on this observer; override this to perform initialization or issue an initial request.

The default implementation requests Long.MAX_VALUE.