Observer

rx

Interface Observer<T>

Type Parameters:

T - the type of item the Observer expects to observe

All Known Implementing Classes:

AsyncSubject, BehaviorSubject, BufferUntilSubscriber, OperatorReplay.SubjectWrapper, PublishSubject, ReplaySubject, SafeSubscriber, SerializedObserver, SerializedSubject, SerializedSubscriber, Subject, Subscriber, TestObserver, TestSubject, TestSubscriber
```
public interface Observer<T>
```
Provides a mechanism for receiving push-based notifications.
After an Observer calls an Observable's subscribe method, the Observable calls the Observer's onNext(T) method to provide notifications. A well-behaved Observable will call an Observer's onCompleted() method exactly once or the Observer's onError(java.lang.Throwable) method exactly once.

See Also:

RxJava Wiki: Observable

Method Summary

All Methods

Instance Methods

Abstract Methods
Modifier and Type	Method and Description
`void`	`onCompleted()` Notifies the Observer that the `Observable` has finished sending push-based notifications.
`void`	`onError(Throwable e)` Notifies the Observer that the `Observable` has experienced an error condition.
`void`	`onNext(T t)` Provides the Observer with a new item to observe.

- Method Detail
  - onCompleted
```
void onCompleted()
```
    Notifies the Observer that the Observable has finished sending push-based notifications.
    The Observable will not call this method if it calls onError(java.lang.Throwable).
  - onError
```
void onError(Throwable e)
```
    Notifies the Observer that the Observable has experienced an error condition.
    If the Observable calls this method, it will not thereafter call onNext(T) or onCompleted().
    
    Parameters:
    
    e - the exception encountered by the Observable
  - onNext
```
void onNext(T t)
```
    Provides the Observer with a new item to observe.
    The Observable may call this method 0 or more times.
    
    The Observable will not call this method again after it calls either onCompleted() or onError(java.lang.Throwable).
    
    Parameters:
    
    t - the item emitted by the Observable