This section explains theBlockingObservable subclass. A Blocking Observable extends the ordinary Observable class by providing a set of operators on the items emitted by the Observable that block.

To transform anObservable into aBlockingObservable, use theObservable.toBlocking( ) method or theBlockingObservable.from( ) method.

• forEach( ) — invoke a function on each item emitted by the Observable; block until the Observable completes
• first( ) — block until the Observable emits an item, then return the first item emitted by the Observable
• firstOrDefault( ) — block until the Observable emits an item or completes, then return the first item emitted by the Observable or a default item if the Observable did not emit an item
• last( ) — block until the Observable completes, then return the last item emitted by the Observable
• lastOrDefault( ) — block until the Observable completes, then return the last item emitted by the Observable or a default item if there is no last item
• mostRecent( ) — returns an iterable that always returns the item most recently emitted by the Observable
• next( ) — returns an iterable that blocks until the Observable emits another item, then returns that item
• latest( ) — returns an iterable that blocks until or unless the Observable emits an item that has not been returned by the iterable, then returns that item
• single( ) — if the Observable completes after emitting a single item, return that item, otherwise throw an exception
• singleOrDefault( ) — if the Observable completes after emitting a single item, return that item, otherwise return a default item
• toFuture( ) — convert the Observable into a Future
• toIterable( ) — convert the sequence emitted by the Observable into an Iterable
• getIterator( ) — convert the sequence emitted by the Observable into an Iterator

This documentation accompanies its explanations with a modified form of "marble diagrams." Here is how these marble diagrams represent Blocking Observables:

• javadoc:BlockingObservable
• javadoc:toBlocking()
• javadoc:BlockingObservable.from()