io.reactivex.observable.observers

Class ResourceSingleObserver<T>

java.lang.Object

io.reactivex.observable.observers.ResourceSingleObserver<T>

Type Parameters:

T - the value type

All Implemented Interfaces:

io.reactivex.common.Disposable, SingleObserver<T>

public abstract class ResourceSingleObserver<T>
extends java.lang.Object
implements SingleObserver<T>, io.reactivex.common.Disposable

An abstract SingleObserver that allows asynchronous cancellation of its subscription and the associated resources.

All pre-implemented final methods are thread-safe.

Override the protected onStart() to perform initialization when this ResourceSingleObserver 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() in onSuccess() and onError() explicitly.

Use add(Disposable) to associate resources (as Disposables) with this ResourceSingleObserver 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 ResourceSingleObserver and then add/remove resources to/from the CompositeDisposable freely.

Like all other consumers, ResourceSingleObserver can be subscribed only once. Any subsequent attempt to subscribe it to a new source will yield an IllegalStateException with message "Disposable already set!".

Implementation of onStart(), SingleObserver.onSuccess(Object) and SingleObserver.onError(Throwable) are not allowed to throw any unchecked exceptions.

Example

 Disposable d =
     Single.just(1).delay(1, TimeUnit.SECONDS)
     .subscribeWith(new ResourceSingleObserver<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();
         }
     });
 // ...
 d.dispose();
 

Constructor Summary

Constructors

Constructor and Description
ResourceSingleObserver()

Method Summary

Modifier and Type	Method and Description
void	add(io.reactivex.common.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(io.reactivex.common.Disposable s) Provides the SingleObserver with the means of cancelling (disposing) the connection (channel) with the Single in both synchronous (from within onSubscribe(Disposable) itself) and asynchronous manner.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.reactivex.observable.SingleObserver

onError, onSuccess

Constructor Detail

ResourceSingleObserver

public ResourceSingleObserver()

Method Detail

add

public final void add(@NonNull
                      io.reactivex.common.Disposable resource)

Adds a resource to this ResourceObserver.

Parameters:

resource - the resource to add

Throws:

java.lang.NullPointerException - if resource is null

onSubscribe

public final void onSubscribe(@NonNull
                              io.reactivex.common.Disposable s)

Description copied from interface: SingleObserver

Provides the SingleObserver with the means of cancelling (disposing) the connection (channel) with the Single in both synchronous (from within onSubscribe(Disposable) itself) and asynchronous manner.

Specified by:

onSubscribe in interface SingleObserver<T>

Parameters:

s - the Disposable instance whose Disposable.dispose() can be called anytime to cancel the connection

onStart

protected void onStart()

Called once the upstream sets a Subscription on this ResourceObserver.

You can perform initialization at this moment. The default implementation does nothing.

dispose

public final void dispose()

Cancels the main disposable (if any) and disposes the resources associated with this ResourceObserver (if any).

This method can be called before the upstream calls onSubscribe at which case the main Disposable will be immediately disposed.

Specified by:

dispose in interface io.reactivex.common.Disposable

isDisposed

public final boolean isDisposed()

Returns true if this ResourceObserver has been disposed/cancelled.

Specified by:

isDisposed in interface io.reactivex.common.Disposable

Returns:

true if this ResourceObserver has been disposed/cancelled