Subscriber

java.lang.Object
- rx.Subscriber<T>

Type Parameters:

T - the type of items the Subscriber expects to observe

All Implemented Interfaces:

Observer<T>, Subscription

Direct Known Subclasses:

BlockingOperatorToIterator.SubscriberIterator, SafeSubscriber, SerializedSubscriber, TestSubscriber
```
public abstract class Subscriber<T>
extends Object
implements Observer<T>, Subscription
```
Provides a mechanism for receiving push-based notifications from Observables, and permits manual unsubscribing from these Observables.
After a Subscriber calls an Observable's subscribe method, the Observable calls the Subscriber's Observer.onNext(T) method to emit items. A well-behaved Observable will call a Subscriber's Observer.onCompleted() method exactly once or the Subscriber's Observer.onError(java.lang.Throwable) method exactly once.

See Also:

ReactiveX documentation: Observable

Constructor Summary

Constructors

Modifier	Constructor and Description
`protected`	`Subscriber()`
`protected`	`Subscriber(Subscriber<?> subscriber)` Construct a Subscriber by using another Subscriber for backpressure and for holding the subscription list (when `this.add(sub)` is called this will in fact call `subscriber.add(sub)`).
`protected`	`Subscriber(Subscriber<?> subscriber, boolean shareSubscriptions)` Construct a Subscriber by using another Subscriber for backpressure and optionally for holding the subscription list (if `shareSubscriptions` is `true` then when `this.add(sub)` is called this will in fact call `subscriber.add(sub)`).

Method Summary

All Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`void`	`add(Subscription s)` Adds a `Subscription` to this Subscriber's list of subscriptions if this list is not marked as unsubscribed.
`boolean`	`isUnsubscribed()` Indicates whether this Subscriber has unsubscribed from its list of subscriptions.
`void`	`onStart()` This method is invoked when the Subscriber and Observable have been connected but the Observable has not yet begun to emit items or send notifications to the Subscriber.
`protected void`	`request(long n)` Request a certain maximum number of emitted items from the Observable this Subscriber is subscribed to.
`void`	`setProducer(Producer p)` If other subscriber is set (by calling constructor `Subscriber(Subscriber)` or `Subscriber(Subscriber, boolean)`) then this method calls `setProducer` on the other subscriber.
`void`	`unsubscribe()` Stops the receipt of notifications on the `Subscriber` that was registered when this Subscription was received.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface rx.Observer
onCompleted, onError, onNext

- Constructor Detail
  - Subscriber
```
protected Subscriber()
```
  - Subscriber
```
protected Subscriber(Subscriber<?> subscriber)
```
    Construct a Subscriber by using another Subscriber for backpressure and for holding the subscription list (when this.add(sub) is called this will in fact call subscriber.add(sub)).
    
    Parameters:
    
    subscriber - the other Subscriber
  - Subscriber
```
protected Subscriber(Subscriber<?> subscriber,
                     boolean shareSubscriptions)
```
    Construct a Subscriber by using another Subscriber for backpressure and optionally for holding the subscription list (if shareSubscriptions is true then when this.add(sub) is called this will in fact call subscriber.add(sub)).
    To retain the chaining of subscribers when setting shareSubscriptions to false, add the created instance to subscriber via add(rx.Subscription).
    
    Parameters:
    
    subscriber - the other Subscriber
    
    shareSubscriptions - true to share the subscription list in subscriber with this instance
    
    Since:
    
    1.0.6
- Method Detail
  - add
```
public final void add(Subscription s)
```
    Adds a Subscription to this Subscriber's list of subscriptions if this list is not marked as unsubscribed. If the list is marked as unsubscribed, add will indicate this by explicitly unsubscribing the new Subscription as well.
    
    Parameters:
    
    s - the Subscription to add
  - unsubscribe
```
public final void unsubscribe()
```
    Description copied from interface: Subscription
    
    Stops the receipt of notifications on the Subscriber that was registered when this Subscription was received.
    This allows unregistering an Subscriber before it has finished receiving all events (i.e. before onCompleted is called).
  - isUnsubscribed
```
public final boolean isUnsubscribed()
```
    Indicates whether this Subscriber has unsubscribed from its list of subscriptions.
    
    Specified by:
    
    isUnsubscribed in interface Subscription
    
    Returns:
    
    true if this Subscriber has unsubscribed from its subscriptions, false otherwise
  - onStart
```
public void onStart()
```
    This method is invoked when the Subscriber and Observable have been connected but the Observable has not yet begun to emit items or send notifications to the Subscriber. Override this method to add any useful initialization to your subscription, for instance to initiate backpressure.
  - request
```
protected final void request(long n)
```
    Request a certain maximum number of emitted items from the Observable this Subscriber is subscribed to. This is a way of requesting backpressure. To disable backpressure, pass Long.MAX_VALUE to this method.
    Requests are additive but if a sequence of requests totals more than Long.MAX_VALUE then Long.MAX_VALUE requests will be actioned and the extras may be ignored. Arriving at Long.MAX_VALUE by addition of requests cannot be assumed to disable backpressure. For example, the code below may result in Long.MAX_VALUE requests being actioned only.
```
 request(100);
 request(Long.MAX_VALUE-1);
 
```
    Parameters:
    
    n - the maximum number of items you want the Observable to emit to the Subscriber at this time, or Long.MAX_VALUE if you want the Observable to emit items at its own pace
    
    Throws:
    
    IllegalArgumentException - if n is negative
  - setProducer
```
public void setProducer(Producer p)
```
    If other subscriber is set (by calling constructor Subscriber(Subscriber) or Subscriber(Subscriber, boolean)) then this method calls setProducer on the other subscriber. If the other subscriber is not set and no requests have been made to this subscriber then p.request(Long.MAX_VALUE) is called. If the other subscriber is not set and some requests have been made to this subscriber then p.request(n) is called where n is the accumulated requests to this subscriber.
    
    Parameters:
    
    p - producer to be used by this subscriber or the other subscriber (or recursively its other subscriber) to make requests from

Class Subscriber<T>

Constructor Summary

Constructors

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface rx.Observer

Constructor Detail

Subscriber

Subscriber

Subscriber

Method Detail

add

unsubscribe

isUnsubscribed

onStart

request

setProducer