Book Image

Learning Spring Boot 3.0 - Third Edition

By : Greg L. Turnquist
Book Image

Learning Spring Boot 3.0 - Third Edition

By: Greg L. Turnquist

Overview of this book

Spring Boot 3 brings more than just the powerful ability to build secure web apps on top of a rock-solid database. It delivers new options for testing, deployment, Docker support, and native images for GraalVM, along with ways to squeeze out more efficient usage of existing resources. This third edition of the bestseller starts off by helping you build a simple app, and then shows you how to secure, test, bundle, and deploy it to production. Next, you’ll familiarize yourself with the ability to go “native” and release using GraalVM. As you advance, you’ll explore reactive programming and get a taste of scalable web controllers and data operations. The book goes into detail about GraalVM native images and deployment, teaching you how to secure your application using both routes and method-based rules and enabling you to apply the lessons you’ve learned to any problem. If you want to gain a thorough understanding of building robust applications using the core functionality of Spring Boot, then this is the book for you. By the end of this Spring Boot book, you’ll be able to build an entire suite of web applications using Spring Boot and deploy them to any platform you need.
Table of Contents (17 chapters)
1
Part 1: The Basics of Spring Boot
3
Part 2: Creating an Application with Spring Boot
8
Part 3: Releasing an Application with Spring Boot
12
Part 4: Scaling an Application with Spring Boot

Trying out R2DBC

Before we can fetch any data, we have to load some data. While this is normally something our DBA deals with, for this chapter we’ll just have to do it ourselves. To do that, we need to create a Spring component that will automatically kick off once our application is up. Create a new class named Startup and add the following code:

@Configuration
public class Startup {
  @Bean
  CommandLineRunner initDatabase(R2dbcEntityTemplate 
    template) {
      return args -> {
        // Coming soon!
      }
    }
}

This code can be described as follows:

  • @Configuration: Spring’s annotation to flag this class as a collection of bean definitions, needed to autoconfigure our application
  • @Bean: Spring’s annotation to turn this method into a Spring bean, added to the application context...