Part 2. Vital techniques

This part of the book (chapters 3 to 6) is all about exploring vital programming knowledge and techniques with Java.

We’ll start with a chapter on Dependency Injection, a common technique used to decouple code and increase testability and comprehension. As well as explaining the basics of Dependency Injection, we’ll also cover how it evolved and discuss how a best practice turned into a design pattern and from there into a framework (and even a Java standard).

Next, we’ll get to grips with the multicore CPU revolution occurring in hardware. The well-grounded Java developer needs to be aware of Java’s concurrency capabilities, and how to use them to get the most out of modern processors. Despite Java having strong support for concurrent programming since 2006 (Java 5), it’s an area that has been poorly understood and underutilized, so we’ll dedicate a chapter to this material.

You’ll learn about the Java Memory Model and how threading and concurrency is implemented in that model. Once you have some theory under your belt, we’ll guide you through the features of the java.util.concurrent package (and beyond) to start building your practical grounding in Java concurrency.

Next, we’ll turn to classloading. Many Java developers don’t have a good understanding of how the JVM actually loads, links, and verifies classes. This leads to frustration and wasted time when an “incorrect” version of some class is executed due to some sort of classloader conflict.