Book Image

Practical Cloud-Native Java Development with MicroProfile

By : Emily Jiang, Andrew McCright, John Alcorn, David Chan, Alasdair Nottingham
Book Image

Practical Cloud-Native Java Development with MicroProfile

By: Emily Jiang, Andrew McCright, John Alcorn, David Chan, Alasdair Nottingham

Overview of this book

In this cloud-native era, most applications are deployed in a cloud environment that is public, private, or a combination of both. To ensure that your application performs well in the cloud, you need to build an application that is cloud native. MicroProfile is one of the most popular frameworks for building cloud-native applications, and fits well with Kubernetes. As an open standard technology, MicroProfile helps improve application portability across all of MicroProfile's implementations. Practical Cloud-Native Java Development with MicroProfile is a comprehensive guide that helps you explore the advanced features and use cases of a variety of Jakarta and MicroProfile specifications. You'll start by learning how to develop a real-world stock trader application, and then move on to enhancing the application and adding day-2 operation considerations. You'll gradually advance to packaging and deploying the application. The book demonstrates the complete process of development through to deployment and concludes by showing you how to monitor the application's performance in the cloud. By the end of this book, you will master MicroProfile's latest features and be able to build fast and efficient cloud-native applications.
Table of Contents (18 chapters)
Section 1: Cloud-Native Applications
Section 2: MicroProfile 4.1 Deep Dive
Section 3: End-to-End Project Using MicroProfile
Section 4: MicroProfile Standalone Specifications and the Future

Managing life cycle and DI with CDI

By default, JAX-RS resources are created for each request. While this might be useful in some cases, it would be far more efficient if they were singletons. That way, we wouldn't be creating new object instances (an expensive operation) for each request, and we wouldn't be generating excess garbage after the request is completed.

While we could create an Application subclass that returns the resources via the getSingletons() method, that would prevent the container from automatically discovering and registering resources and providers. Another reason to avoid that approach is that the getSingletons() method is deprecated in a future version of JAX-RS and will eventually be removed.

Instead, we can use Context and Dependency Injection (CDI). CDI uses annotations to allow developers to declaratively manage object life cycles and perform injections of fields, constructors, and setter methods.


CDI has several built-in scopes...