About this Book

Spring Boot aims to simplify Spring development. As such, Spring Boot’s reach stretches to touch everything that Spring touches. It’d be impossible to write a book that covers every single way that Spring Boot can be used, as doing so would involve covering every single technology that Spring itself supports. Instead, Spring Boot in Action aims to distill Spring Boot into four main topics: auto-configuration, starter dependencies, the command-line interface, and the Actuator. Along the way, we’ll touch on a few Spring features as necessary, but the focus will be primarily on Spring Boot.

Spring Boot in Action is for all Java developers. Although some background in Spring could be considered a prerequisite, Spring Boot has a way of making Spring more approachable even to those new to Spring. Nevertheless, because this book will be focused on Spring Boot and will not dive deeply into Spring itself, you may find it helpful to pair it with other Spring materials such as Spring in Action, Fourth Edition (Manning, 2014).

Roadmap

Spring Boot in Action is divided into seven chapters:

• In chapter 1 you’ll be given an overview of Spring Boot, including the essentials of automatic configuration, starter dependencies, the command-line interface, and the Actuator.
• Chapter 2 takes a deeper dive into Spring Boot, focusing on automatic configuration and starter dependencies. In this chapter, you’ll build a complete Spring application using very little explicit configuration.
• Chapter 3 picks up where chapter 2 leaves off, showing how you can influence automatic configuration by setting application properties or completely overriding automatic configuration when it doesn’t meet your needs.
• In chapter 4 we’ll look at how to write automated integration tests for Spring Boot applications.
• In chapter 5 you’ll see how the Spring Boot CLI offers a compelling alternative to conventional Java development by enabling you to write complete applications as a set of Groovy scripts that are run from the command line.
• While we’re on the subject of Groovy, chapter 6 takes a look at Grails 3, the latest version of the Grails framework, which is now based on Spring Boot.
• In chapter 7 you’ll see how to leverage Spring Boot’s Actuator to dig inside of a running application and see what makes it tick. You’ll see how to use Actuator web endpoints as well as a remote shell and JMX MBeans to peek at the internals of an application.
• Chapter 8 wraps things up by discussing various options for deploying your Spring Boot application, including traditional application server deployment and cloud deployment.

Code conventions and downloads

There are many code examples throughout this book. These examples will always appear in a fixed-width code font like this. Any class name, method name, or XML fragment within the normal text of the book will appear in code font as well. Many of Spring’s classes and packages have exceptionally long (but expressive) names. Because of this, line-continuation markers () may be included when necessary. Not all code examples in this book will be complete. Often I only show a method or two from a class to focus on a particular topic.

Complete source code for the applications found in the book can be downloaded from the publisher’s website at www.manning.com/books/spring-boot-in-action.

Author Online

The purchase of Spring Boot in Action includes free access to a private web forum run by Manning Publications, where you can make comments about the book, ask technical questions, and receive help from the author and from other users. To access the forum and subscribe to it, point your web browser to www.manning.com/books/spring-boot-in-action. This page provides information on how to get on the forum once you are registered, what kind of help is available, and the rules of conduct on the forum.

Manning’s commitment to our readers is to provide a venue where a meaningful dialogue between individual readers and between readers and the author can take place. It is not a commitment to any specific amount of participation on the part of the author whose contribution to the forum remains voluntary (and unpaid). We suggest you try asking the author some challenging questions lest his interest stray!

The Author Online forum and the archives of previous discussions will be accessible from the publisher’s website as long as the book is in print.

About the cover illustration

The figure on the cover of Spring Boot in Action is captioned “Habit of a Tartar in Kasan,” which is the capital city of the Republic of Tatarstan in Russia. The illustration is taken from Thomas Jefferys’ A Collection of the Dresses of Different Nations, Ancient and Modern (four volumes), London, published between 1757 and 1772. The title page states that these are hand-colored copperplate engravings, heightened with gum arabic. Thomas Jefferys (1719–1771) was called “Geographer to King George III.” He was an English cartographer who was the leading map supplier of his day. He engraved and printed maps for government and other official bodies and produced a wide range of commercial maps and atlases, especially of North America. His work as a mapmaker sparked an interest in local dress customs of the lands he surveyed and mapped, which are brilliantly displayed in this collection.

Fascination with faraway lands and travel for pleasure were relatively new phenomena in the late eighteenth century, and collections such as this one were popular, introducing both the tourist as well as the armchair traveler to the inhabitants of other countries. The diversity of the drawings in Jefferys’ volumes speaks vividly of the uniqueness and individuality of the world’s nations some 200 years ago. Dress codes have changed since then, and the diversity by region and country, so rich at the time, has faded away. It is now often hard to tell the inhabitant of one continent from another. Perhaps, trying to view it optimistically, we have traded a cultural and visual diversity for a more varied personal life. Or a more varied and interesting intellectual and technical life.

At a time when it is hard to tell one computer book from another, Manning celebrates the inventiveness and initiative of the computer business with book covers based on the rich diversity of regional life of two centuries ago, brought back to life by Jeffreys’ pictures.