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)

Building a REST client

So far, we have created a REST API and consumed it in third-party tools such as SoapUI, Postman, or JUnit testing. There might be situations where you will have to consume a REST API using the regular method (service or another controller method) itself like payment API call in service API. It will be useful when you call a third-party API such as PayPal or a weather API in your code. In such situations, having a REST client will be helpful for getting the job done.

Here, we will talk about how to build a REST client to consume another REST API in our method. Before moving onto that, we will talk a little bit about RestTemplate in Spring.


RestTemplate is a Spring class that is used to consume the REST API from the client side through HTTP. By using RestTemplate, we can keep the REST API consumer in the same application as well, so we don't need a third-party application or another application to consume our API. RestTemplate can be used use to call GET, POST...