Book Image

The Java Workshop

By : David Cuartielles, Andreas Göransson, Eric Foster-Johnson
4 (2)
Book Image

The Java Workshop

4 (2)
By: David Cuartielles, Andreas Göransson, Eric Foster-Johnson

Overview of this book

Java is a versatile, popular programming language used across a wide range of industries. Learning how to write effective Java code can take your career to the next level, and The Java Workshop will help you do just that. This book is designed to take the pain out of Java coding and teach you everything you need to know to be productive in building real-world software. The Workshop starts by showing you how to use classes, methods, and the built-in Collections API to manipulate data structures effortlessly. You’ll dive right into learning about object-oriented programming by creating classes and interfaces and making use of inheritance and polymorphism. After learning how to handle exceptions, you’ll study the modules, packages, and libraries that help you organize your code. As you progress, you’ll discover how to connect to external databases and web servers, work with regular expressions, and write unit tests to validate your code. You’ll also be introduced to functional programming and see how to implement it using lambda functions. By the end of this Workshop, you’ll be well-versed with key Java concepts and have the knowledge and confidence to tackle your own ambitious projects with Java.
Table of Contents (20 chapters)

Publisher

The publisher holds the data that other components are interested in getting. The publisher will wait until a subscriber who is interested in the data requests n-number of items to be sent, and will only then start sending those items to the subscriber.

Asking for a specific number of items, rather than asking for everything, is called backpressure, and is very important in the Reactive Streams specification. This backpressure lets listeners request only as many items as they can handle at a time, ensuring that the application will not stall or crash.

The interface for Publisher in Flow, and Reactive Streams looks like this:

@FunctionalInterface
public static interface Publisher<T> {
    public void subscribe(Subscriber<? super T> subscriber);
}

You'll notice that it's a functional interface, which can be implemented as a lambda, should you wish.

SubmissionPublisher

Creating a fully functional Publisher can be quite...