Package io.reactivex.rxjava3.subscribers

Class DisposableSubscriber<T>

  • Type Parameters:
    T - the received value type.
    All Implemented Interfaces:
    FlowableSubscriber<T>, Disposable, org.reactivestreams.Subscriber<T>
    Direct Known Subclasses:
    BlockingFlowableLatest.LatestSubscriberIterator, BlockingFlowableNext.NextSubscriber, FlowableBufferExactBoundary.BufferBoundarySubscriber, FlowableDebounce.DebounceSubscriber.DebounceInnerSubscriber, FlowableWindowBoundary.WindowBoundaryInnerSubscriber
    public abstract class DisposableSubscriber<T>
extends java.lang.Object
implements FlowableSubscriber<T>, Disposable
    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 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.

    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(), 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.

    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();

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) java.util.concurrent.atomic.AtomicReference<org.reactivestreams.Subscription> upstream  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void cancel()
      Cancels the Subscription set via onSubscribe(Subscription) or makes sure a Subscription set asynchronously (later) is cancelled immediately.
      void dispose()
      Dispose the resource, the operation should be idempotent.
      boolean isDisposed()
      Returns true if this resource has been disposed.
      protected void onStart()
      Called once the single upstream Subscription is set via onSubscribe(Subscription).
      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 the specified amount from the upstream if its Subscription is set via onSubscribe already.

      • 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

    • Field Detail

      • upstream

        final java.util.concurrent.atomic.AtomicReference<org.reactivestreams.Subscription> upstream

    • Constructor Detail

      • DisposableSubscriber

        public DisposableSubscriber()

    • 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 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(Subscription) leads to NullPointerException and meant to be called from inside onStart() or Subscriber.onNext(Object).

        Parameters:
        n - the request amount, positive

      • cancel

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

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

      • isDisposed

        public final boolean isDisposed()
        Description copied from interface: Disposable
        Returns true if this resource has been disposed.
        Specified by:
        isDisposed in interface Disposable
        Returns:
        true if this resource has been disposed

      • dispose

        public final void dispose()
        Description copied from interface: Disposable
        Dispose the resource, the operation should be idempotent.
        Specified by:
        dispose in interface Disposable