Book Image

Java 9 Dependency Injection

By : Nilang Patel, Krunal Patel
3 (1)
Book Image

Java 9 Dependency Injection

3 (1)
By: Nilang Patel, Krunal Patel

Overview of this book

Dependency Injection (DI) is a design pattern that allows us to remove the hard-coded dependencies and make our application loosely coupled, extendable, and maintainable. We can implement DI to move the dependency resolution from compile-time to runtime. This book will be your one stop guide to write loosely coupled code using the latest features of Java 9 with frameworks such as Spring 5 and Google Guice. We begin by explaining what DI is and teaching you about IoC containers. Then you’ll learn about object compositions and their role in DI. You’ll find out how to build a modular application and learn how to use DI to focus your efforts on the business logic unique to your application and let the framework handle the infrastructure work to put it all together. Moving on, you’ll gain knowledge of Java 9’s new features and modular framework and how DI works in Java 9. Next, we’ll explore Spring and Guice, the popular frameworks for DI. You’ll see how to define injection keys and configure them at the framework-specific level. After that, you’ll find out about the different types of scopes available in both popular frameworks. You’ll see how to manage dependency of cross-cutting concerns while writing applications through aspect-oriented programming. Towards the end, you’ll learn to integrate any third-party library in your DI-enabled application and explore common pitfalls and recommendations to build a solid application with the help of best practices, patterns, and anti-patterns in DI.
Table of Contents (14 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Java 9 introduction


Before learning what's new in Java 9, we need to know one of the important components of Java, which is Java Development Kit (JDK).

JDK is a collection of Java Standard Edition (Java SE), Java Enterprise Edition (Java EE), Java Micro Edition platforms (Java ME), and different tools such as javac, Java console, JAR, JShell, Jlink, and it provides all the libraries for developing, debugging, and monitoring for building Java-based applications.

Java 9 has come up with almost over 100 new features and enhancements in different categories of JDK, such as tools, security, deployment, performance tuning, API changes of core libraries, and javadoc. 

Key features

Let's look at some of the key features of Java 9 in brief, which will change Java software development:

  • Java Platform Module System (JPMS)
  • JShell (REPL)—The Java Shell
  • JLink—Module Linker
  • Multi-Release JAR Files
  • Stream API enhancements
  • Stack—Walking API
  • Immutable collections with convenient factory methods
  • Support of HTTP 2.0

Java...