Book Image

Learning Spring Boot 2.0 - Second Edition

By : Greg L. Turnquist, Greg L. Turnquist
Book Image

Learning Spring Boot 2.0 - Second Edition

By: Greg L. Turnquist, Greg L. Turnquist

Overview of this book

Spring Boot provides a variety of features that address today's business needs along with today's scalable requirements. In this book, you will learn how to leverage powerful databases and Spring Boot's state-of-the-art WebFlux framework. This practical guide will help you get up and running with all the latest features of Spring Boot, especially the new Reactor-based toolkit. The book starts off by helping you build a simple app, then shows you how to bundle and deploy it to the cloud. From here, we take you through reactive programming, showing you how to interact with controllers and templates and handle data access. Once you're done, you can start writing unit tests, slice tests, embedded container tests, and even autoconfiguration tests. We go into detail about developer tools, AMQP messaging, WebSockets, security, and deployment. You will learn how to secure your application using both routes and method-based rules. By the end of the book, you'll have built a social media platform from which to apply the lessons you have learned to any problem. If you want a good understanding of building scalable applications using the core functionality of Spring Boot, this is the book for you.
Table of Contents (11 chapters)

Publishing saved comments to a chat service

In the previous chapter, we connected our images service to the comments service via Spring Cloud Stream. This let us transmit new comments over the wire to a service dedicated to storing them in a MongoDB data store.

The following screenshot shows us entering a new comment:

To carry on this use case to its natural conclusion, it's expected that after storing a message, we'd want to share it with everyone, right? To do so, let's pick up with the comment microservice's CommentService.

In the previous chapter, the comments service transformed an incoming stream of Flux<Comment> into a Flux<Void>, a stream of voids. This had the effect of, essentially, dropping the stream at this point. In this chapter, we want to take that incoming stream of comments and forward them.

This is accomplished by altering the...