hu.akarnokd.rxjava2.subscribers

Class AsyncObserver<T>

java.lang.Object

hu.akarnokd.rxjava2.subscribers.AsyncObserver<T>

Type Parameters:

T - the value type

All Implemented Interfaces:

Disposable, org.reactivestreams.Subscriber<T>

public abstract class AsyncObserver<T>
extends java.lang.Object
implements org.reactivestreams.Subscriber<T>, Disposable

An abstract Subscriber implementation that allows asynchronous cancellation of its subscription.

This implementation let's you chose if the AsyncObserver manages resources or not, thus saving memory on cases where there is no need for that.

All pre-implemented final methods are thread-safe.

Constructor Summary

Constructors

Constructor and Description
AsyncObserver() Constructs an AsyncObserver with resource support.
AsyncObserver(boolean withResources) Constructs an AsyncObserver and allows specifying if it should support resources or not.

Method Summary

Modifier and Type	Method and Description
void	add(Disposable resource) Adds a resource to this AsyncObserver.
protected void	cancel() Cancels the subscription (if any) and disposes the resources associated with this AsyncObserver (if any).
void	dispose() Dispose the resource, the operation should be idempotent.
boolean	isDisposed() Returns true if this AsyncObserver has been disposed/cancelled.
protected void	onStart() Called once the upstream sets a Subscription on this AsyncObserver.
void	onSubscribe(org.reactivestreams.Subscription s)
protected void	request(long n) Request the specified amount of elements from upstream.
boolean	supportsResources() Returns true if this AsyncObserver supports resources added via the add() method.

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

Constructor Detail

AsyncObserver

public AsyncObserver()

Constructs an AsyncObserver with resource support.

AsyncObserver

public AsyncObserver(boolean withResources)

Constructs an AsyncObserver and allows specifying if it should support resources or not.

Parameters:

withResources - true if resource support should be on.

Method Detail

add

public final void add(Disposable resource)

Adds a resource to this AsyncObserver.

Note that if the AsyncObserver doesn't manage resources, this method will throw an IllegalStateException. Use supportsResources() to determine if this AsyncObserver manages resources or not.

Parameters:

resource - the resource to add

Throws:

java.lang.NullPointerException - if resource is null

java.lang.IllegalStateException - if this AsyncObserver doesn't manage resources

See Also:

supportsResources()

supportsResources

public final boolean supportsResources()

Returns true if this AsyncObserver supports resources added via the add() method.

Returns:

true if this AsyncObserver supports resources added via the add() method

See Also:

add(Disposable)

onSubscribe

public final void onSubscribe(org.reactivestreams.Subscription s)

Specified by:

onSubscribe in interface org.reactivestreams.Subscriber<T>

onStart

protected void onStart()

Called once the upstream sets a Subscription on this AsyncObserver.

You can perform initialization at this moment. The default implementation requests Long.MAX_VALUE from upstream.

request

protected final void request(long n)

Request the specified amount of elements from upstream.

This method can be called before the upstream calls onSubscribe(). When the subscription happens, all missed requests are requested.

Parameters:

n - the request amount, must be positive

cancel

protected final void cancel()

Cancels the subscription (if any) and disposes the resources associated with this AsyncObserver (if any).

This method can be called before the upstream calls onSubscribe at which case the Subscription will be immediately cancelled.

dispose

public final void dispose()

Description copied from interface: Disposable

Dispose the resource, the operation should be idempotent.

Specified by:

dispose in interface Disposable

isDisposed

public final boolean isDisposed()

Returns true if this AsyncObserver has been disposed/cancelled.

Returns:

true if this AsyncObserver has been disposed/cancelled