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)

Using Spring Boot's autoconfiguration report

As we've seen in this book so far, Spring Boot autoconfigures beans to help us avoid configuring infrastructure and instead focus on coding business requirements. However, sometimes, we may want to know what Spring Boot did (or didn't) do for us.

That's why it has an autoconfiguration report. Essentially, every time a bean is selected based on some conditional check, Spring Boot logs the decision (yea or nay) and offers it to us in many different ways.

The simplest approach is to add --debug to the run configuration. In the following screenshot, we can see how to set it in IntelliJ:

If we launch our app with --debug as a program argument, an autoconfiguration report is printed out to the console:

That's nice, and during certain failure scenarios, the report will print out automatically to help with postmortem...