Jetty ReactiveStreams HTTP Client

ReactiveStreams has gained a lot of attention recently, especially because of its inclusion in JDK 9 in the Flow class.

A number of libraries have been written on top of ReactiveStreams that provide a functional-style API that makes asynchronous processing of a data stream very easy.
Notable examples of such libraries are RxJava 2 and Spring Reactor. ReactiveStreams provides a common API for all these libraries so that they are interoperable, and interoperable with any library that offers a ReactiveStreams API.

It is not uncommon that applications (especially REST applications) need to interact with a HTTP client to either consume or produce a stream of data. The typical example is an application making REST calls to a server and obtaining response content that needs to be transformed using ReactiveStreams APIs.

Another example is having a stream of data that you need to upload to a server using a REST call.

It’s evident that it would be great if there was a HTTP client that provides ReactiveStreams API, and this is what we have done with the Jetty ReactiveStreams HttpClient.

Maven coordinates:

<dependency>
  <groupId>org.eclipse.jetty</groupId>
  <artifactId>jetty-reactive-httpclient</artifactId>
  <version>0.9.0</version>
</dependency>

The Jetty ReactiveStreams HttpClient is a tiny wrapper over Jetty’s HttpClient; Jetty’s HttpClient was already fully non-blocking and already had full support for backpressure, so wrapping it with the ReactiveStreams API was fairly simple.

You can find detailed usage examples at the project page on GitHub.