Cloud Native Java: Building Cloud Applications in Java

Introduction

The book "Cloud Native Java" (authors — Josh Long and Kenny Bastani) was published in 2017, but it still remains one of the most in-depth practical guides for building cloud applications on the Java platform. In an era when microservices and containerization have become the de facto standard, this book offers not just a set of recipes, but a holistic methodology based on the 12-factor approach and the Spring ecosystem.

Josh Long is a well-known Spring evangelist from Pivotal (now VMware), and Kenny Bastani is an expert in microservices and cloud architectures. Their joint work is 624 pages of dense but engaging material that will be useful for both experienced Java developers and architects transitioning to the cloud.

What is this book about?

"Cloud Native Java" does not teach the basics of the Java language — it teaches you to think cloud-native. The main focus is on:

• Microservice architecture — how to break a monolith into loosely coupled services using Spring Boot and Spring Cloud.
• 12-factor methodology — codebase, dependencies, configuration, logs, processes, and other principles formulated by Heroku.
• Cloud Foundry platform — how to deploy, scale, and manage applications in a cloud environment (although examples are easily adaptable to Kubernetes).
• Reactive programming — an introduction to Spring WebFlux and reactive streams for high-load systems.
• Security and monitoring — OAuth2, JWT, distributed tracing (Spring Cloud Sleuth, Zipkin).

The book is built around an end-to-end example — a task management application that gradually evolves from a simple monolith into a full-fledged cloud system.

Who is this book for?

The target audience is developers already familiar with Java and Spring who want to transition to modern cloud practices. If you:

• have been writing Java for at least a year;
• know the basics of Spring (DI, MVC, JPA);
• want to understand how to build microservices that are easy to scale and update without downtime;
• are interested in DevOps and cloud platforms (Cloud Foundry, Kubernetes, Docker);

— this book is for you. It will be difficult for Java beginners: the authors do not explain basic constructs but immediately move on to architectural decisions.

What will the reader learn?

After reading, you will be able to:

• design microservices following the 12-factor methodology;
• use Spring Boot to quickly create production-ready services;
• configure external configuration via Config Server;
• implement service discovery (Eureka) and load balancing (Ribbon, Feign);
• add resilience with Hystrix (circuit breaker);
• organize distributed tracing and monitoring;
• deploy applications to Cloud Foundry and manage their lifecycle;
• use reactive approaches (WebFlux) for non-blocking I/O;
• integrate OAuth2 and JWT for secure service interaction.

Each chapter contains practical exercises and links to a GitHub repository with the full example code.

Strengths

The first thing that wins you over is the depth and systematic approach. The book doesn't just list technologies; it explains why a particular decision was made. For example, the authors thoroughly discuss why a 12-factor application should store configuration in environment variables rather than files, and how this affects scaling.

The second is practical orientation. Each concept is backed by code that can be run immediately. The chapters on Cloud Foundry are especially valuable: even if you don't use this platform, the principles of deployment and application management are universal.

The third is relevance. Despite being from 2017, 90% of the material remains relevant. Spring Cloud, Hystrix, Eureka