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

Server-sent events

SSE, or server-sent events, is a means by which we can stream data from the server to the client. Typically, a REST request is very short-lived--make a connection, send the request, get a response, close the connection. Sometimes, though, the REST server may not have all of the data that the client wants at the time of the request (for example, reading data from another data source such as a log file or network socket). So, it would be nice to be able to push that data to the client as it becomes available. That's exactly what SSE allows us to do. We'll look into that in more detail later.

Finally, we start the server instance with a call to JettyHttpContainerFactory.createServer(). Since we need to be able to stop the server later, we capture the server instance, and store it in an instance variable. We call startServer() from onStartCommand() as follows:

    private static final Object lock = new Object(); 
    public int onStartCommand(Intent intent, int flags, int startId...