Reactive Streams is an initiative trying to standardize asynchronous stream processing with non-blocking  back-pressure. With Java 9, new classes in the java.util.concurrent.flow package offer a semantically equivalent counterpart to this standard that may be adopted by other frameworks.

In the following short tutorial we’re implementing examples for reactive streams with Java 9 and the Flow API, with RxJava2, with Akka, with Reactor and finally there is an example in RxJava1, too though it does not follow the standard.

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Message Driven Beans are no new concept due to the fact that they exist since EJB 2.0 but in Java EE 6 and the EJB 3.0 specification it is even more fun to use them.

In this tutorial we’re going to take a look at the specification and create an example application that transfers some objects via the Java Message Service to a Message-Driven Bean deployed on a GlassFish application server.

If you’re not interested in theory please skip to chapter 6 and directly start creating an application – otherwise we’ll begin with a short introduction into the JMS terminology and the concept of a Message-Driven-Bean..

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Having read an interesting comparison by Lindenlabs evaluating modern message broker systems like ActiveMQ, ApacheQpid and amongst others – RabbitMQ – I wanted to take a quick look at the last one and built a small application producing and consuming some sample messages.

If you need some lecture on getting started with RabbitMQ or the key concepts of messaging I strongly recommend reading this list of introductional articles from the RabbitMQ homepage.

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