Preface

After nearly 15 years of working with Spring and having written five editions of this book (not to mention Spring Boot in Action), you’d think that it’d be hard to come up with something exciting and new to say about Spring when writing the preface for this book. But nothing could be further from the truth!

Every single release of Spring, Spring Boot, and all of the other projects in the Spring ecosystem unleashes some new amazing capabilities that rekindle the fun in developing applications. With Spring reaching a significant milestone with its 5.0 release and Spring Boot releasing version 2.0, there’s so much more Spring to enjoy that it was a no-brainer to write another edition of Spring in Action.

The big story of Spring 5 is reactive programming support, including Spring WebFlux, a brand new reactive web framework that borrows its programming model from Spring MVC, allowing developers to create web applications that scale better and make better use of fewer threads. Moving toward the backend of a Spring application, the latest edition of Spring Data enables the creation of reactive, non-blocking data repositories. And all of this is built on top of Project Reactor, a Java library for working with reactive types.

In addition to the new reactive programming features of Spring 5, Spring Boot 2 now provides even more autoconfiguration support than ever before as well as a completely reimagined Actuator for peeking into and manipulating a running application.