rx.subjects

Class Subject<T,R>

java.lang.Object

rx.Observable<R>

rx.subjects.Subject<T,R>

All Implemented Interfaces:

Observer<T>

Direct Known Subclasses:

AsyncSubject, BehaviorSubject, PublishSubject, ReplaySubject, SerializedSubject, TestSubject

public abstract class Subject<T,R>
extends Observable<R>
implements Observer<T>

Represents an object that is both an Observable and an Observer.

Nested Class Summary

Nested classes/interfaces inherited from class rx.Observable

Observable.OnSubscribe<T>, Observable.Operator<R,T>, Observable.Transformer<T,R>

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Subject(Observable.OnSubscribe<R> onSubscribe)

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Throwable	getThrowable() Returns the Throwable that terminated the Subject.
T	getValue() Returns the current or latest value of the Subject if there is such a value and the subject hasn't terminated with an exception.
java.lang.Object[]	getValues() Returns a snapshot of the currently buffered non-terminal events.
T[]	getValues(T[] a) Returns a snapshot of the currently buffered non-terminal events into the provided a array or creates a new array if it has not enough capacity.
boolean	hasCompleted() Check if the Subject has terminated normally.
abstract boolean	hasObservers() Indicates whether the Subject has Observers subscribed to it.
boolean	hasThrowable() Check if the Subject has terminated with an exception.
boolean	hasValue() Check if the Subject has any value.
SerializedSubject<T,R>	toSerialized() Wraps a Subject so that it is safe to call its various on methods from different threads.

Methods inherited from class rx.Observable

all, amb, amb, amb, amb, amb, amb, amb, amb, amb, ambWith, asObservable, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, cache, cache, cast, collect, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, compose, concat, concat, concat, concat, concat, concat, concat, concat, concat, concatMap, concatWith, contains, count, countLong, create, debounce, debounce, debounce, defaultIfEmpty, defer, delay, delay, delay, delay, delaySubscription, delaySubscription, delaySubscription, dematerialize, distinct, distinct, distinctUntilChanged, distinctUntilChanged, doOnCompleted, doOnEach, doOnEach, doOnError, doOnNext, doOnRequest, doOnSubscribe, doOnTerminate, doOnUnsubscribe, elementAt, elementAtOrDefault, empty, error, exists, filter, finallyDo, first, first, firstOrDefault, firstOrDefault, flatMap, flatMap, flatMap, flatMap, flatMap, flatMap, flatMapIterable, flatMapIterable, forEach, forEach, forEach, from, from, from, from, from, groupBy, groupBy, groupJoin, ignoreElements, interval, interval, isEmpty, join, just, just, just, just, just, just, just, just, just, just, last, last, lastOrDefault, lastOrDefault, lift, limit, map, materialize, merge, merge, merge, merge, merge, merge, merge, merge, merge, merge, merge, merge, merge, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeDelayError, mergeWith, nest, never, observeOn, ofType, onBackpressureBlock, onBackpressureBlock, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureDrop, onBackpressureDrop, onBackpressureLatest, onErrorResumeNext, onErrorResumeNext, onErrorReturn, onExceptionResumeNext, publish, publish, range, range, reduce, reduce, repeat, repeat, repeat, repeat, repeatWhen, repeatWhen, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, replay, retry, retry, retry, retryWhen, retryWhen, sample, sample, sample, scan, scan, sequenceEqual, sequenceEqual, serialize, share, single, single, singleOrDefault, singleOrDefault, skip, skip, skip, skipLast, skipLast, skipLast, skipUntil, skipWhile, startWith, startWith, startWith, startWith, startWith, startWith, startWith, startWith, startWith, startWith, startWith, subscribe, subscribe, subscribe, subscribe, subscribe, subscribe, subscribeOn, switchIfEmpty, switchMap, switchOnNext, take, take, take, takeFirst, takeLast, takeLast, takeLast, takeLast, takeLast, takeLastBuffer, takeLastBuffer, takeLastBuffer, takeLastBuffer, takeLastBuffer, takeUntil, takeUntil, takeWhile, throttleFirst, throttleFirst, throttleLast, throttleLast, throttleWithTimeout, throttleWithTimeout, timeInterval, timeInterval, timeout, timeout, timeout, timeout, timeout, timeout, timeout, timeout, timer, timer, timer, timer, timestamp, timestamp, toBlocking, toList, toMap, toMap, toMap, toMultimap, toMultimap, toMultimap, toMultimap, toSortedList, toSortedList, toSortedList, toSortedList, unsafeSubscribe, unsubscribeOn, using, using, window, window, window, window, window, window, window, window, window, window, window, window, withLatestFrom, zip, zip, zip, zip, zip, zip, zip, zip, zip, zip, zipWith, zipWith

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

Subject

protected Subject(Observable.OnSubscribe<R> onSubscribe)

Method Detail

hasObservers

public abstract boolean hasObservers()

Indicates whether the Subject has Observers subscribed to it.

Returns:

true if there is at least one Observer subscribed to this Subject, false otherwise

toSerialized

public final SerializedSubject<T,R> toSerialized()

Wraps a Subject so that it is safe to call its various on methods from different threads.

When you use an ordinary Subject as a Subscriber, you must take care not to call its Observer.onNext(T) method (or its other on methods) from multiple threads, as this could lead to non-serialized calls, which violates the Observable contract and creates an ambiguity in the resulting Subject.

To protect a Subject from this danger, you can convert it into a SerializedSubject with code like the following:

mySafeSubject = myUnsafeSubject.toSerialized();
 

Returns:

SerializedSubject wrapping the current Subject

hasThrowable

@Experimental
public boolean hasThrowable()

Check if the Subject has terminated with an exception.

The operation is threadsafe.

Returns:

true if the subject has received a throwable through onError.

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

hasCompleted

@Experimental
public boolean hasCompleted()

Check if the Subject has terminated normally.

The operation is threadsafe.

Returns:

true if the subject completed normally via onCompleted

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

getThrowable

@Experimental
public java.lang.Throwable getThrowable()

Returns the Throwable that terminated the Subject.

The operation is threadsafe.

Returns:

the Throwable that terminated the Subject or null if the subject hasn't terminated yet or if it terminated normally.

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

hasValue

@Experimental
public boolean hasValue()

Check if the Subject has any value.

Use the getValue() method to retrieve such a value.

Note that unless hasCompleted() or hasThrowable() returns true, the value retrieved by getValue() may get outdated.

The operation is threadsafe.

Returns:

true if and only if the subject has some value but not an error

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

getValue

@Experimental
public T getValue()

Returns the current or latest value of the Subject if there is such a value and the subject hasn't terminated with an exception.

The method can return null for various reasons. Use hasValue(), hasThrowable() and hasCompleted() to determine if such null is a valid value, there was an exception or the Subject terminated without receiving any value.

The operation is threadsafe.

Returns:

the current value or null if the Subject doesn't have a value, has terminated with an exception or has an actual null as a value.

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

getValues

@Experimental
public java.lang.Object[] getValues()

Returns a snapshot of the currently buffered non-terminal events.

The operation is threadsafe.

Returns:

a snapshot of the currently buffered non-terminal events.

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)

getValues

@Experimental
public T[] getValues(T[] a)

Returns a snapshot of the currently buffered non-terminal events into the provided a array or creates a new array if it has not enough capacity.

If the subject's values fit in the specified array with room to spare (i.e., the array has more elements than the list), the element in the array immediately following the end of the subject's values is set to null.

The operation is threadsafe.

Parameters:

a - the array to fill in

Returns:

the array a if it had enough capacity or a new array containing the available values

Since:

(If this graduates from being an Experimental class method, replace this parenthetical with the release number)