Book Image

Building RESTful Web Services with Spring 5 - Second Edition

By : Raja CSP Raman, Ludovic Dewailly
Book Image

Building RESTful Web Services with Spring 5 - Second Edition

By: Raja CSP Raman, Ludovic Dewailly

Overview of this book

REST is an architectural style that tackles the challenges of building scalable web services. In today's connected world, APIs have taken a central role on the web. APIs provide the fabric through which systems interact, and REST has become synonymous with APIs.The depth, breadth, and ease of use of Spring makes it one of the most attractive frameworks in the Java ecosystem. Marrying the two technologies is therefore a very natural choice.This book takes you through the design of RESTful web services and leverages the Spring Framework to implement these services. Starting from the basics of the philosophy behind REST, you'll go through the steps of designing and implementing an enterprise-grade RESTful web service. Taking a practical approach, each chapter provides code samples that you can apply to your own circumstances.This second edition brings forth the power of the latest Spring 5.0 release, working with MVC built-in as well as the front end framework. It then goes beyond the use of Spring to explores approaches to tackle resilience, security, and scalability concerns. Improve performance of your applications with the new HTTP 2.0 standards. You'll learn techniques to deal with security in Spring and discover how to implement unit and integration test strategies.Finally, the book ends by walking you through building a Java client for your RESTful web service, along with some scaling techniques using the new Spring Reactive libraries.
Table of Contents (21 chapters)
Title Page
Copyright and Credits
Packt Upsell
Spring Security and JWT (JSON Web Token)


We have already used Postman in previous chapters for testing our REST APIs. Postman will be helpful when we need to test the application completely. In Postman, we can write test suites to validate our REST API endpoints.

Getting all the users – Postman

First, we shall start with a simple API for getting all the users:


The earlier method will get all the users. The Postman screenshot for getting all the users is as follows:

In the preceding screenshot, we can see that we get all the users that we added before. We have used the GET method to call this API.

Adding a user – Postman

Let's try to use the POST method in user to add a new user:


Add the user, as shown in the following screenshot:

In the preceding result, we can see the JSON output:

     "result" : "added"

Generating a JWT – Postman

Let's try generating the token (JWT) by calling the generate token API in Postman using the following code: