Book Image

Architecting Modern Java EE Applications

By : Sebastian Daschner
Book Image

Architecting Modern Java EE Applications

By: Sebastian Daschner

Overview of this book

Java EE 8 brings with it a load of features, mainly targeting newer architectures such as microservices, modernized security APIs, and cloud deployments. This book will teach you to design and develop modern, business-oriented applications using Java EE 8. It shows how to structure systems and applications, and how design patterns and Domain Driven Design aspects are realized in the age of Java EE 8. You will learn about the concepts and principles behind Java EE applications, and how to effect communication, persistence, technical and cross-cutting concerns, and asynchronous behavior. This book covers Continuous Delivery, DevOps, infrastructure-as-code, containers, container orchestration technologies, such as Docker and Kubernetes, and why and especially how Java EE fits into this world. It also covers the requirements behind containerized, zero-dependency applications and how modern Java EE application servers support these approaches. You will also learn about automated, fast, and reliable software tests, in different test levels, scopes, and test technologies. This book covers the prerequisites and challenges of distributed systems that lead to microservice, shared-nothing architectures. The challenges and solutions of consistency versus scalability will further lead us to event sourcing, event-driven architectures, and the CQRS principle. This book also includes the nuts and bolts of application performance as well as how to realize resilience, logging, monitoring and tracing in a modern enterprise world. Last but not least the demands of securing enterprise systems are covered. By the end, you will understand the ins and outs of Java EE so that you can make critical design decisions that not only live up to, but also surpass your clients' expectations.
Table of Contents (22 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback
Appendix: Links and further resources

How to design systems landscapes

With all of these challenges and overheads involved, a lot of scenarios still require distribution. It's important to mention, that there must be enough motivation behind distributing systems. Distribution comes with costs and risks. If it's not necessary to distribute, building monolithic applications is always to be preferred.

Now, let's look into how to design reasonable system landscapes, tailored for business requirements.

Context maps and bounded contexts

Bounded contexts define the application's responsibilities in business logic, behavior, and data ownership. So-called context maps, as described in Domain-Driven Design, represent the entire system landscape. It shows the individual responsibilities, contexts, and belongings of its applications. Bounded contexts therefore fit within a context map to show how they exchange information among each other.

The following shows the context map of the cars domain, including two bounded contexts:

It's advisable...