How Is This Book Structured?

Chapter 1 starts with an overview of REST. We cover REST fundamentals and abstractions such as resources and representations. We then discuss web infrastructure such as URIs, HTTP methods, and HTTP response codes. We also cover Richardson’s Maturity Model, which provides a classification of REST services.

Chapter 2 provides detailed coverage of Spring Web MVC. We begin with a gentle introduction to the Spring Framework and cover its two important concepts—dependency injection and aspect-oriented programming. Then we take a deeper look at the different components that make up Spring Web MVC.

Chapter 3 introduces Spring Boot, a Spring project that simplifies the bootstrapping of Spring applications. We then use Spring Boot to build a Hello World REST application. Finally, we look at some tools that can be used to access REST applications.

Chapter 4 discusses the beginnings of a RESTful application named QuickPoll. We analyze the requirements and design resources and their representations. Using Spring MVC components, we implement a set of RESTful services.

Chapter 5 covers error handling in REST services. Well-designed, meaningful error responses play an important role in the adoption of REST services. We design a custom error response for QuickPoll and implement the design. We also add validation capabilities to the inputs provided by users. Finally, we look at techniques for externalizing the error messages to property files.

Chapter 6 begins with an overview of the Swagger specification and its associated tools/frameworks. We then implement Swagger in QuickPoll to generate interactive documentation. We also customize Swagger and Swagger UI to meet our application requirements.

Chapter 7 covers the different strategies for versioning a REST API. We then look at implementing versioning in QuickPoll using the URI versioning approach. We also review the different approaches for dealing with large datasets using pagination and sorting.

Chapter 8 begins with a discussion of different strategies for securing REST services. We provide a detailed treatment of OAuth2 and review its different components. We then use the Spring Security framework to implement Basic Authentication in the QuickPoll application.

Chapter 9 covers building REST clients and testing REST APIs. We use Spring’s RestTemplate features to build a REST client that works with different versions of the QuickPoll API. We then take a deeper look into the Spring MVC Test framework and examine its core classes. Finally, we write unit and integration tests to test the REST API.

Chapter 10 discusses the HATEOAS constraint that allows developers to build flexible and loosely coupled REST services. It also covers the HAL hypermedia format. We then modify the QuickPoll application such that the Poll representations are generated following HATEOAS principles.

Target Audience

Spring REST is intended for enterprise and web developers using Java and Spring who want to build REST applications. The book requires a basic knowledge of Java, Spring, and the Web but no prior exposure to REST.

Downloading the Source Code

The source code for the examples in this book can be downloaded via the Download Source Code button located at www.apress.com/9781484274767 .

The downloaded source code contains a number of folders named ChapterX, in which X represents the corresponding chapter number. Each ChapterX folder contains two subfolders: a starter folder and a final folder. The starter folder houses a QuickPoll project that you can use as a basis to follow along the solution described in the corresponding chapter. Even though each chapter builds on the previous one, the starter project allows you to skip around the book. For example, if you are interested in learning about security, you can simply load the QuickPoll application under the Chapter8starter folder and follow the solution described in Chapter 8. As the name suggests, the final folder contains the expected end state for that chapter.

Chapters 1 and 2 don’t have any associated code. Therefore, the corresponding ChapterX folders for those chapters contain empty starter and final folders. In Chapter 3, we build a Hello World application, so Chapter 3’s starter and final folders contain the hello-rest application. Starting from Chapter 4, the starter and final folders contain QuickPoll project source code.

Contacting the Authors

We always welcome feedback from our readers. If you have any questions or suggestions regarding the contents of this book, you can contact the authors at [email protected] or [email protected].