A pipeline is a sequence of processing components through which data or messages flow from an input toward an output. Each component can alter the data, use it, or translate it between an external system and an application’s domain. section 10.0
Pipelines support two closely related ways of building applications:
- Spring Integration assembles message-handling components with configuration, allowing data to move between external systems and application logic. section 10.0
- Reactive programming declares a stream of transformations instead of a fixed sequence of imperative steps; data is processed as it becomes available. section 11.2 section 11.1
- A reactive pipeline may process an ongoing or endless stream, and its operations are not assumed to run on one particular thread. section 11.2 section 11.1
Transforming a name into a greeting
A Reactor pipeline starts with one value, converts the name to uppercase, transforms it into a greeting, and subscribes to print the result. Mono represents a pipeline with no more than one item; Flux represents zero, one, many, or potentially infinite items. section 11.2
Mono.just("Craig")
.map(n -> n.toUpperCase())
.map(cn -> "Hello, " + cn + "!")
.subscribe(System.out::println);
Inspect the complete Reactor example: just() supplies the value, map() applies each transformation, and subscribe() consumes the resulting greeting. section 11.2
