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

Lookup, a NetBeans fundamental

What's a Lookup? It is a general registry permitting clients to find instances of services (implementation of a given interface). To put it another way, it is a mechanism by which we can publish various artifacts, and other parts of the system can look up these artifacts by a key (either a Class or a Lookup.Template, which we'll not discuss here), with no coupling between the modules.

This is often used, as we'll see, to look up the implementations of a service interface. Do you recall earlier when I mentioned that often we see APIs defined in one module and implementations in another? This is where that comes in especially handy. Suppose you're developing an API to retrieve photos from an online service (which would be a great feature for this application!). You plan to deliver an implementation for one service, say Google Photos, but want to enable a third-party developer to provide an implementation for, say, Flickr. If you put the required API interfaces...