Hands-On Reactive Programming in Spring 5

Combining Reactive Streams

Of course, Project Reactor allows the combining of many incoming streams into one outgoing stream. The named operators have many overrides but perform the following transformations:

• The concat operator concatenates all sources by forwarding received elements downstream. When the operator concatenates two streams, at first, it consumes and resends all elements of the first stream, then does the same for the second.
• The merge operator merges data from upstream sequences into one downstream sequence. Unlike  the concat operator, upstream sources are subscribed to eagerly (at the same time).
• The zip operator subscribes to all upstreams, waits for all sources to emit one element and then combines received elements into ...