Class ResourceMaybeObserver<T>
- java.lang.Object
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- io.reactivex.rxjava3.observers.ResourceMaybeObserver<T>
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- Type Parameters:
T
- the value type
- All Implemented Interfaces:
MaybeObserver<T>
,Disposable
public abstract class ResourceMaybeObserver<T> extends java.lang.Object implements MaybeObserver<T>, Disposable
An abstractMaybeObserver
that allows asynchronous cancellation of its subscription and associated resources.All pre-implemented final methods are thread-safe.
Note that
MaybeObserver.onSuccess(Object)
,MaybeObserver.onError(Throwable)
andMaybeObserver.onComplete()
are exclusive to each other, unlike a regularObserver
, andonComplete()
is never called after anonSuccess()
.Override the protected
onStart()
to perform initialization when thisResourceMaybeObserver
is subscribed to a source.Use the public
dispose()
method to dispose the sequence externally and release all resources.To release the associated resources, one has to call
dispose()
inonSuccess()
,onError()
andonComplete()
explicitly.Use
add(Disposable)
to associate resources (asDisposable
s) with thisResourceMaybeObserver
that will be cleaned up whendispose()
is called. Removing previously associated resources is not possible but one can create aCompositeDisposable
, associate it with thisResourceMaybeObserver
and then add/remove resources to/from theCompositeDisposable
freely.Like all other consumers,
ResourceMaybeObserver
can be subscribed only once. Any subsequent attempt to subscribe it to a new source will yield anIllegalStateException
with message"It is not allowed to subscribe with a(n) <class name> multiple times."
.Implementation of
onStart()
,MaybeObserver.onSuccess(Object)
,MaybeObserver.onError(Throwable)
andMaybeObserver.onComplete()
are not allowed to throw any unchecked exceptions.Example
Disposable d = Maybe.just(1).delay(1, TimeUnit.SECONDS) .subscribeWith(new ResourceMaybeObserver<Integer>() { @Override public void onStart() { add(Schedulers.single() .scheduleDirect(() -> System.out.println("Time!"), 2, TimeUnit.SECONDS)); } @Override public void onSuccess(Integer t) { System.out.println(t); dispose(); } @Override public void onError(Throwable t) { t.printStackTrace(); dispose(); } @Override public void onComplete() { System.out.println("Done!"); dispose(); } }); // ... d.dispose();
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Field Summary
Fields Modifier and Type Field Description private ListCompositeDisposable
resources
The resource composite, can never be null.private java.util.concurrent.atomic.AtomicReference<Disposable>
upstream
The active subscription.
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Constructor Summary
Constructors Constructor Description ResourceMaybeObserver()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
add(@NonNull Disposable resource)
Adds a resource to thisResourceMaybeObserver
.void
dispose()
Cancels the main disposable (if any) and disposes the resources associated with thisResourceMaybeObserver
(if any).boolean
isDisposed()
Returns true if thisResourceMaybeObserver
has been disposed/cancelled.protected void
onStart()
Called once the upstream sets aDisposable
on thisResourceMaybeObserver
.void
onSubscribe(@NonNull Disposable d)
Provides theMaybeObserver
with the means of cancelling (disposing) the connection (channel) with theMaybe
in both synchronous (from withinonSubscribe(Disposable)
itself) and asynchronous manner.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface io.reactivex.rxjava3.core.MaybeObserver
onComplete, onError, onSuccess
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Field Detail
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upstream
private final java.util.concurrent.atomic.AtomicReference<Disposable> upstream
The active subscription.
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resources
private final ListCompositeDisposable resources
The resource composite, can never be null.
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Method Detail
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add
public final void add(@NonNull @NonNull Disposable resource)
Adds a resource to thisResourceMaybeObserver
.- Parameters:
resource
- the resource to add- Throws:
java.lang.NullPointerException
- if resource isnull
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onSubscribe
public final void onSubscribe(@NonNull @NonNull Disposable d)
Description copied from interface:MaybeObserver
Provides theMaybeObserver
with the means of cancelling (disposing) the connection (channel) with theMaybe
in both synchronous (from withinonSubscribe(Disposable)
itself) and asynchronous manner.- Specified by:
onSubscribe
in interfaceMaybeObserver<T>
- Parameters:
d
- theDisposable
instance whoseDisposable.dispose()
can be called anytime to cancel the connection
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onStart
protected void onStart()
Called once the upstream sets aDisposable
on thisResourceMaybeObserver
.You can perform initialization at this moment. The default implementation does nothing.
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dispose
public final void dispose()
Cancels the main disposable (if any) and disposes the resources associated with thisResourceMaybeObserver
(if any).This method can be called before the upstream calls
onSubscribe(Disposable)
at which case the mainDisposable
will be immediately disposed.- Specified by:
dispose
in interfaceDisposable
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isDisposed
public final boolean isDisposed()
Returns true if thisResourceMaybeObserver
has been disposed/cancelled.- Specified by:
isDisposed
in interfaceDisposable
- Returns:
- true if this
ResourceMaybeObserver
has been disposed/cancelled
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