T - the value typepublic abstract class ResourceObserver<T> extends Object implements Observer<T>, Disposable
Observer that allows asynchronous cancellation of its subscription and associated resources.
All pre-implemented final methods are thread-safe.
To release the associated resources, one has to call dispose()
in onError() and onComplete() explicitly.
Use add(Disposable) to associate resources (as Disposables)
with this ResourceObserver that will be cleaned up when dispose() is called.
Removing previously associated resources is not possible but one can create a
CompositeDisposable, associate it with this
ResourceObserver and then add/remove resources to/from the CompositeDisposable
freely.
Use the dispose() to dispose the sequence from within an
onNext implementation.
Like all other consumers, ResourceObserver 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(), Observer.onNext(Object), Observer.onError(Throwable)
and Observer.onComplete() are not allowed to throw any unchecked exceptions.
If for some reason this can't be avoided, use Observable.safeSubscribe(io.reactivex.Observer)
instead of the standard subscribe() method.
Example
Disposable d =
Observable.range(1, 5)
.subscribeWith(new ResourceObserver<Integer>() {
@Override public void onStart() {
add(Schedulers.single()
.scheduleDirect(() -> System.out.println("Time!"),
2, TimeUnit.SECONDS));
request(1);
}
@Override public void onNext(Integer t) {
if (t == 3) {
dispose();
}
System.out.println(t);
}
@Override public void onError(Throwable t) {
t.printStackTrace();
dispose();
}
@Override public void onComplete() {
System.out.println("Done!");
dispose();
}
});
// ...
d.dispose();
| Constructor and Description |
|---|
ResourceObserver() |
| Modifier and Type | Method and Description |
|---|---|
void |
add(Disposable resource)
Adds a resource to this ResourceObserver.
|
void |
dispose()
Cancels the main disposable (if any) and disposes the resources associated with
this ResourceObserver (if any).
|
boolean |
isDisposed()
Returns true if this ResourceObserver has been disposed/cancelled.
|
protected void |
onStart()
Called once the upstream sets a Subscription on this ResourceObserver.
|
void |
onSubscribe(Disposable d)
Provides the Observer with the means of cancelling (disposing) the
connection (channel) with the Observable in both
synchronous (from within
Observer.onNext(Object)) and asynchronous manner. |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitonComplete, onError, onNextpublic final void add(@NonNull Disposable resource)
resource - the resource to addNullPointerException - if resource is nullpublic final void onSubscribe(Disposable d)
ObserverObserver.onNext(Object)) and asynchronous manner.onSubscribe in interface Observer<T>d - the Disposable instance whose Disposable.dispose() can
be called anytime to cancel the connectionprotected void onStart()
You can perform initialization at this moment. The default implementation does nothing.
public final void dispose()
This method can be called before the upstream calls onSubscribe at which case the main Disposable will be immediately disposed.
dispose in interface Disposablepublic final boolean isDisposed()
isDisposed in interface Disposable