public final class OrElse<T> extends GraphStage<UniformFanInShape<T,T>>Takes two streams and passes the first through, the secondary stream is only passed through if the primary stream completes without passing any elements through. When the first element is passed through from the primary the secondary is cancelled. Both incoming streams are materialized when the operator is materialized.
On errors the operator is failed regardless of source of the error.
'''Emits when''' element is available from primary stream or the primary stream closed without emitting any elements and an element is available from the secondary stream
'''Backpressures when''' downstream backpressures
'''Completes when''' the primary stream completes after emitting at least one element, when the primary stream completes without emitting and the secondary stream already has completed or when the secondary stream completes
'''Cancels when''' downstream cancels
Constructors Constructor Description
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description
static <T> OrElse<T>
shape()The shape of a graph is all that is externally visible: its inlets and outlets.
Methods inherited from class akka.stream.stage.GraphStageWithMaterializedValue
createLogicAndMaterializedValue, traversalBuilder, withAttributes
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
public UniformFanInShape<T,T> shape()Description copied from interface:
GraphThe shape of a graph is all that is externally visible: its inlets and outlets.
protected Attributes initialAttributes()
public GraphStageLogic createLogic(Attributes inheritedAttributes)
public java.lang.String toString()