Book Image

Mastering Spring Boot 2.0

By : Dinesh Rajput
Book Image

Mastering Spring Boot 2.0

By: Dinesh Rajput

Overview of this book

Spring is one of the best frameworks on the market for developing web, enterprise, and cloud ready software. Spring Boot simplifies the building of complex software dramatically by reducing the amount of boilerplate code, and by providing production-ready features and a simple deployment model. This book will address the challenges related to power that come with Spring Boot's great configurability and flexibility. You will understand how Spring Boot configuration works under the hood, how to overwrite default configurations, and how to use advanced techniques to prepare Spring Boot applications to work in production. This book will also introduce readers to a relatively new topic in the Spring ecosystem – cloud native patterns, reactive programming, and applications. Get up to speed with microservices with Spring Boot and Spring Cloud. Each chapter aims to solve a specific problem or teach you a useful skillset. By the end of this book, you will be proficient in building and deploying your Spring Boot application.
Table of Contents (23 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Exception handling


By default, Spring Cloud Netflix Feign throws FeignException for any type errors in any situation, but it is not always suitable and you don't want this same exception for every situation in your project. Netflix Feign allows you to set your own application-specific exception instead. You can do it easily by providing your own implementation of feign.codec.ErrorDecoder to Feign.builder.errorDecoder().

Let's see an example of such an ErrorDecoder implementation:

public class AccountErrorDecoder implements ErrorDecoder { 
 
    @Override 
    public Exception decode(String methodKey, Response response) { 
        if (response.status() >= 400 && response.status() <= 499) { 
            return new AccountClientException( 
                    response.status(), 
                    response.reason() 
            ); 
        } 
        if (response.status() >= 500 && response.status() <= 599) { 
            return new AccountServerException( 
     ...