Functional Programming for Java Developers

Preface

Welcome to Functional Programming for Java Developers

Why should a Java developer learn about functional programming (FP)? After all, hasn’t functional programming been safely hidden in academia for decades? Isn’t object-oriented programming (OOP) all we really need? This book explains why functional programming has become an important tool for the challenges of our time and how you, a Java developer, can use it to your advantage.

The recent interest in functional programming started as a response to the growing pervasiveness of concurrency as a way of scaling horizontally, through parallelism. Multithreaded programming (see, e.g., [Goetz2006]) is difficult to do well and few developers are good at it. As we’ll see, functional programming offers better strategies for writing robust, concurrent software.

An example of the greater need for horizontal scalability is the growth of massive data sets requiring management and analysis, the so-called big data trend. These are data sets that are too large for traditional database management systems. They require clusters of computers to store and process the data. Today, it’s not just Google, Yahoo!, Facebook, and Twitter who work with big data. Many organizations face this challenge.

Once you learn the benefits of functional programming, you find that it improves all the code you write. When I learned functional programming a few years ago, it re-energized my enthusiasm for programming. I saw new, exciting ways to approach old problems. ...