Book Image

Java 9 Programming Blueprints

By : Jason Lee
Book Image

Java 9 Programming Blueprints

By: Jason Lee

Overview of this book

Java is a powerful language that has applications in a wide variety of fields. From playing games on your computer to performing banking transactions, Java is at the heart of everything. The book starts by unveiling the new features of Java 9 and quickly walks you through the building blocks that form the basis of writing applications. There are 10 comprehensive projects in the book that will showcase the various features of Java 9. You will learn to build an email filter that separates spam messages from all your inboxes, a social media aggregator app that will help you efficiently track various feeds, and a microservice for a client/server note application, to name a few. The book covers various libraries and frameworks in these projects, and also introduces a few more frameworks that complement and extend the Java SDK. Through the course of building applications, this book will not only help you get to grips with the various features of Java 9, but will also teach you how to design and prototype professional-grade applications with performance and security considerations.
Table of Contents (19 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback
Taking Notes with Monumentum

Updating the process list

If the application started and showed a list of processes, but never updated that list, it wouldn't be very useful at all. What we then need is a way to update the list periodically, and for that, we'll use a Thread.

As you may or may not know, a Thread is roughly a means to run a task in the background (the Javadoc describes it as a thread of execution in a program). A system can be single or multithreaded, depending on the needs and runtime environment of the system. And multithreaded programming is hard to get right. Luckily, our use case here is fairly simple, but we must still exercise caution, or we'll see some really unexpected behavior.

Ordinarily, the advice you would get when creating a Thread is to implement a Runnable interface, which you will then pass to the thread's constructor, and that's very good advice, as it makes your class hierarchy much more flexible, since you're not tied to a concrete base class (Runnable is an interface). In our case, however...