Class DefaultSubscriber<T>

java.lang.Object
io.reactivex.rxjava3.subscribers.DefaultSubscriber<T>
Type Parameters:
T - the value type

Example


 Flowable.range(1, 5)
     .subscribe(new DefaultSubscriber<Integer>() {
         @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!");
         }
     });
 
All Implemented Interfaces:
FlowableSubscriber<T>, org.reactivestreams.Subscriber<T>
Direct Known Subclasses:
BlockingFlowableMostRecent.MostRecentSubscriber

public abstract class DefaultSubscriber<T> extends Object implements FlowableSubscriber<T>
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 "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.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    (package private) org.reactivestreams.Subscription
     
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    protected final void
    Cancels the upstream's Subscription.
    protected void
    Called once the subscription has been set on this observer; override this to perform initialization or issue an initial request.
    final 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 final 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
  • Field Details

    • upstream

      org.reactivestreams.Subscription upstream
  • Constructor Details

    • DefaultSubscriber

      public DefaultSubscriber()
  • Method Details

    • 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.