BlockingObservable

java.lang.Object
- rx.observables.BlockingObservable<T>

Type Parameters:

T - the type of item emitted by the BlockingObservable
```
public final class BlockingObservable<T>
extends Object
```
BlockingObservable is a variety of Observable that provides blocking operators. It can be useful for testing and demo purposes, but is generally inappropriate for production applications (if you think you need to use a BlockingObservable this is usually a sign that you should rethink your design).
You construct a BlockingObservable from an Observable with from(Observable) or Observable.toBlocking().

The documentation for this interface makes use of a form of marble diagram that has been modified to illustrate blocking operators. The following legend explains these marble diagrams:

See Also:

RxJava wiki: Blocking Observable Operators

Method Summary

All Methods

Static Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`T`	`first()` Returns the first item emitted by this `BlockingObservable`, or throws `NoSuchElementException` if it emits no items.
`T`	`first(Func1<? super T,Boolean> predicate)` Returns the first item emitted by this `BlockingObservable` that matches a predicate, or throws `NoSuchElementException` if it emits no such item.
`T`	`firstOrDefault(T defaultValue)` Returns the first item emitted by this `BlockingObservable`, or a default value if it emits no items.
`T`	`firstOrDefault(T defaultValue, Func1<? super T,Boolean> predicate)` Returns the first item emitted by this `BlockingObservable` that matches a predicate, or a default value if it emits no such items.
`void`	`forEach(Action1<? super T> onNext)` Invokes a method on each item emitted by this `BlockingObservable` and blocks until the Observable completes.
`static <T> BlockingObservable<T>`	`from(Observable<? extends T> o)` Converts an `Observable` into a `BlockingObservable`.
`Iterator<T>`	`getIterator()` Returns an `Iterator` that iterates over all items emitted by this `BlockingObservable`.
`T`	`last()` Returns the last item emitted by this `BlockingObservable`, or throws `NoSuchElementException` if this `BlockingObservable` emits no items.
`T`	`last(Func1<? super T,Boolean> predicate)` Returns the last item emitted by this `BlockingObservable` that matches a predicate, or throws `NoSuchElementException` if it emits no such items.
`T`	`lastOrDefault(T defaultValue)` Returns the last item emitted by this `BlockingObservable`, or a default value if it emits no items.
`T`	`lastOrDefault(T defaultValue, Func1<? super T,Boolean> predicate)` Returns the last item emitted by this `BlockingObservable` that matches a predicate, or a default value if it emits no such items.
`Iterable<T>`	`latest()` Returns an `Iterable` that returns the latest item emitted by this `BlockingObservable`, waiting if necessary for one to become available.
`Iterable<T>`	`mostRecent(T initialValue)` Returns an `Iterable` that always returns the item most recently emitted by this `BlockingObservable`.
`Iterable<T>`	`next()` Returns an `Iterable` that blocks until this `BlockingObservable` emits another item, then returns that item.
`T`	`single()` If this `BlockingObservable` completes after emitting a single item, return that item, otherwise throw a `NoSuchElementException`.
`T`	`single(Func1<? super T,Boolean> predicate)` If this `BlockingObservable` completes after emitting a single item that matches a given predicate, return that item, otherwise throw a `NoSuchElementException`.
`T`	`singleOrDefault(T defaultValue)` If this `BlockingObservable` completes after emitting a single item, return that item; if it emits more than one item, throw an `IllegalArgumentException`; if it emits no items, return a default value.
`T`	`singleOrDefault(T defaultValue, Func1<? super T,Boolean> predicate)` If this `BlockingObservable` completes after emitting a single item that matches a predicate, return that item; if it emits more than one such item, throw an `IllegalArgumentException`; if it emits no items, return a default value.
`Future<T>`	`toFuture()` Returns a `Future` representing the single value emitted by this `BlockingObservable`.
`Iterable<T>`	`toIterable()` Converts this `BlockingObservable` into an `Iterable`.

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

- Method Detail
  - from
```
public static <T> BlockingObservable<T> from(Observable<? extends T> o)
```
    Converts an Observable into a BlockingObservable.
    
    Parameters:
    
    o - the Observable you want to convert
    
    Returns:
    
    a BlockingObservable version of o
  - forEach
```
public void forEach(Action1<? super T> onNext)
```
    Invokes a method on each item emitted by this BlockingObservable and blocks until the Observable completes.
    Note: This will block even if the underlying Observable is asynchronous.
    
    This is similar to Observable.subscribe(Subscriber), but it blocks. Because it blocks it does not need the Observer.onCompleted() or Observer.onError(Throwable) methods. If the underlying Observable terminates with an error, rather than calling onError, this method will throw an exception.
    
    Parameters:
    
    onNext - the Action1 to invoke for each item emitted by the BlockingObservable
    
    Throws:
    
    RuntimeException - if an error occurs
    
    See Also:
    
    RxJava wiki: forEach()
  - getIterator
```
public Iterator<T> getIterator()
```
    Returns an Iterator that iterates over all items emitted by this BlockingObservable.
    
    Returns:
    
    an Iterator that can iterate over the items emitted by this BlockingObservable
    
    See Also:
    
    RxJava wiki: getIterator()
  - first
```
public T first()
```
    Returns the first item emitted by this BlockingObservable, or throws NoSuchElementException if it emits no items.
    
    Returns:
    
    the first item emitted by this BlockingObservable
    
    Throws:
    
    NoSuchElementException - if this BlockingObservable emits no items
    
    See Also:
    
    RxJava wiki: first()
  - first
```
public T first(Func1<? super T,Boolean> predicate)
```
    Returns the first item emitted by this BlockingObservable that matches a predicate, or throws NoSuchElementException if it emits no such item.
    
    Parameters:
    
    predicate - a predicate function to evaluate items emitted by this BlockingObservable
    
    Returns:
    
    the first item emitted by this BlockingObservable that matches the predicate
    
    Throws:
    
    NoSuchElementException - if this BlockingObservable emits no such items
    
    See Also:
    
    RxJava wiki: first()
  - firstOrDefault
```
public T firstOrDefault(T defaultValue)
```
    Returns the first item emitted by this BlockingObservable, or a default value if it emits no items.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no items
    
    Returns:
    
    the first item emitted by this BlockingObservable, or the default value if it emits no items
    
    See Also:
    
    RxJava wiki: firstOrDefault()
  - firstOrDefault
```
public T firstOrDefault(T defaultValue,
                        Func1<? super T,Boolean> predicate)
```
    Returns the first item emitted by this BlockingObservable that matches a predicate, or a default value if it emits no such items.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no matching items
    
    predicate - a predicate function to evaluate items emitted by this BlockingObservable
    
    Returns:
    
    the first item emitted by this BlockingObservable that matches the predicate, or the default value if this BlockingObservable emits no matching items
    
    See Also:
    
    RxJava wiki: firstOrDefault()
  - last
```
public T last()
```
    Returns the last item emitted by this BlockingObservable, or throws NoSuchElementException if this BlockingObservable emits no items.
    
    Returns:
    
    the last item emitted by this BlockingObservable
    
    Throws:
    
    NoSuchElementException - if this BlockingObservable emits no items
    
    See Also:
    
    RxJava wiki: last()
  - last
```
public T last(Func1<? super T,Boolean> predicate)
```
    Returns the last item emitted by this BlockingObservable that matches a predicate, or throws NoSuchElementException if it emits no such items.
    
    Parameters:
    
    predicate - a predicate function to evaluate items emitted by the BlockingObservable
    
    Returns:
    
    the last item emitted by the BlockingObservable that matches the predicate
    
    Throws:
    
    NoSuchElementException - if this BlockingObservable emits no items
    
    See Also:
    
    RxJava wiki: last()
  - lastOrDefault
```
public T lastOrDefault(T defaultValue)
```
    Returns the last item emitted by this BlockingObservable, or a default value if it emits no items.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no items
    
    Returns:
    
    the last item emitted by the BlockingObservable, or the default value if it emits no items
    
    See Also:
    
    RxJava wiki: lastOrDefault()
  - lastOrDefault
```
public T lastOrDefault(T defaultValue,
                       Func1<? super T,Boolean> predicate)
```
    Returns the last item emitted by this BlockingObservable that matches a predicate, or a default value if it emits no such items.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no matching items
    
    predicate - a predicate function to evaluate items emitted by this BlockingObservable
    
    Returns:
    
    the last item emitted by this BlockingObservable that matches the predicate, or the default value if it emits no matching items
    
    See Also:
    
    RxJava wiki: lastOrDefault()
  - mostRecent
```
public Iterable<T> mostRecent(T initialValue)
```
    Returns an Iterable that always returns the item most recently emitted by this BlockingObservable.
    
    Parameters:
    
    initialValue - the initial value that the Iterable sequence will yield if this BlockingObservable has not yet emitted an item
    
    Returns:
    
    an Iterable that on each iteration returns the item that this BlockingObservable has most recently emitted
    
    See Also:
    
    RxJava wiki: mostRecent()
  - next
```
public Iterable<T> next()
```
    Returns an Iterable that blocks until this BlockingObservable emits another item, then returns that item.
    
    Returns:
    
    an Iterable that blocks upon each iteration until this BlockingObservable emits a new item, whereupon the Iterable returns that item
    
    See Also:
    
    RxJava wiki: next()
  - latest
```
public Iterable<T> latest()
```
    Returns an Iterable that returns the latest item emitted by this BlockingObservable, waiting if necessary for one to become available.
    If this BlockingObservable produces items faster than Iterator.next takes them, onNext events might be skipped, but onError or onCompleted events are not.
    
    Note also that an onNext directly followed by onCompleted might hide the onNext event.
    
    Returns:
    
    an Iterable that always returns the latest item emitted by this BlockingObservable
    
    See Also:
    
    RxJava wiki: latest()
  - single
```
public T single()
```
    If this BlockingObservable completes after emitting a single item, return that item, otherwise throw a NoSuchElementException.
    
    Returns:
    
    the single item emitted by this BlockingObservable
    
    See Also:
    
    RxJava wiki: single()
  - single
```
public T single(Func1<? super T,Boolean> predicate)
```
    If this BlockingObservable completes after emitting a single item that matches a given predicate, return that item, otherwise throw a NoSuchElementException.
    
    Parameters:
    
    predicate - a predicate function to evaluate items emitted by this BlockingObservable
    
    Returns:
    
    the single item emitted by this BlockingObservable that matches the predicate
    
    See Also:
    
    RxJava wiki: single()
  - singleOrDefault
```
public T singleOrDefault(T defaultValue)
```
    If this BlockingObservable completes after emitting a single item, return that item; if it emits more than one item, throw an IllegalArgumentException; if it emits no items, return a default value.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no items
    
    Returns:
    
    the single item emitted by this BlockingObservable, or the default value if it emits no items
    
    See Also:
    
    RxJava wiki: singleOrDefault()
  - singleOrDefault
```
public T singleOrDefault(T defaultValue,
                         Func1<? super T,Boolean> predicate)
```
    If this BlockingObservable completes after emitting a single item that matches a predicate, return that item; if it emits more than one such item, throw an IllegalArgumentException; if it emits no items, return a default value.
    
    Parameters:
    
    defaultValue - a default value to return if this BlockingObservable emits no matching items
    
    predicate - a predicate function to evaluate items emitted by this BlockingObservable
    
    Returns:
    
    the single item emitted by the BlockingObservable that matches the predicate, or the default value if no such items are emitted
    
    See Also:
    
    RxJava wiki: singleOrDefault()
  - toFuture
```
public Future<T> toFuture()
```
    Returns a Future representing the single value emitted by this BlockingObservable.
    If BlockingObservable emits more than one item, Future will receive an IllegalArgumentException. If BlockingObservable is empty, Future will receive an NoSuchElementException.
    
    If the BlockingObservable may emit more than one item, use Observable.toList().toBlocking().toFuture().
    
    Returns:
    
    a Future that expects a single item to be emitted by this BlockingObservable
    
    See Also:
    
    RxJava wiki: toFuture()
  - toIterable
```
public Iterable<T> toIterable()
```
    Converts this BlockingObservable into an Iterable.
    
    Returns:
    
    an Iterable version of this BlockingObservable
    
    See Also:
    
    RxJava wiki: toIterable()