Class DefaultSubscriber<T>
- Type Parameters:
T
- the value typeExample
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
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.
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprotected final void
cancel()
Cancels the upstream'sSubscription
.protected void
onStart()
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 inSubscriber.onNext(Object)
is established before callingSubscription.request(long)
.protected final void
request
(long n) Requests from the upstreamSubscription
.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
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Field Details
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upstream
org.reactivestreams.Subscription upstream
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Constructor Details
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DefaultSubscriber
public DefaultSubscriber()
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Method Details
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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 inSubscriber.onNext(Object)
is established before callingSubscription.request(long)
. In practice this means no initialization should happen after therequest()
call and additional behavior is thread safe in respect toonNext
.- Specified by:
onSubscribe
in interfaceFlowableSubscriber<T>
- Specified by:
onSubscribe
in interfaceorg.reactivestreams.Subscriber<T>
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request
protected final void request(long n) Requests from the upstreamSubscription
.- Parameters:
n
- the request amount, positive
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cancel
protected final void cancel()Cancels the upstream'sSubscription
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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
.
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