A Functional Approach to Java : augmenting object-oriented Java code with functional principles / Ben Weidig.

Format:

Book

Author/Creator:

Weidig, Ben, author.

Language:

English

Subjects (All):

Functional programming (Computer science).

Java (Computer program language).

Object-oriented programs (Computer programs).

Physical Description:

1 online resource

Edition:

First edition.

Place of Publication:

Sebastopol, CA : O'Reilly Media, 2023.

Summary:

Java developers usually tackle the complexity of software development through object-oriented programming (OOP). But not every problem is a good match for OOP. The functional programming (FP) paradigm offers you another approach to solving problems, and Java provides easy-to-grasp FP tools such as lambda expressions and Streams. If you're interested in applying FP concepts to your Java code, this book is for you. Author Ben Weidig highlights different aspects of functional programming and shows you how to incorporate them into your code without going "fully functional." You'll learn how, when, and why to use FP concepts such as immutability and pure functions to write more concise, reasonable, and future-proof code. Many developers seek to expand their horizons by using OOP and FP together. It's no longer either-or; it's both. In this book, you will: Get a high-level overview of functional programming, including the types already available to Java developers Explore different FP concepts and learn how to use them Learn how to augment your code and use Java's new functional features in your daily work without going fully functional Develop a functional mindset and improve your programming skills regardless of language or paradigm.

Contents:

Intro

Copyright

Table of Contents

Preface

New Hardware Needs a New Way of Thinking

Java Can Be Functional, Too

Why I Wrote This Book

Who Should Read This Book

What You Will Learn

What about Android?

A Functional Approach to Android

Navigating This Book

Conventions Used in This Book

Using Code Examples

O'Reilly Online Learning

Acknowledgments

Part I. Functional Basics

Chapter 1. An Introduction to Functional Programming

What Makes a Language Functional?

Functional Programming Concepts

Pure Functions and Referential Transparency

Immutability

Recursion

First-Class and Higher-Order Functions

Functional Composition

Currying

Partial Function Application

Lazy Evaluation

Advantages of Functional Programming

Disadvantages of Functional Programming

Takeaways

Chapter 2. Functional Java

What Are Java Lambdas?

Lambda Syntax

Functional Interfaces

Lambdas and Outside Variables

What about Anonymous Classes?

Lambdas in Action

Creating Lambdas

Calling Lambdas

Method References

Functional Programming Concepts in Java

Pure Functions and Referential Transparency

Immutability

First-Class Citizenship

Chapter 3. Functional Interfaces of the JDK

The Big Four Functional Interface Categories

Functions

Consumers

Suppliers

Predicates

Why So Many Functional Interface Variants?

Function Arity

Primitive Types

Bridging Functional Interfaces

Extending Functional Support

Adding Default Methods

Implementing Functional Interfaces Explicitly

Creating Static Helpers

Part II. A Functional Approach

Chapter 4. Immutability

Mutability and Data Structures in OOP

Immutability (Not Only) in FP

The State of Java Immutability

java.lang.String

Immutable Collections

Primitives and Primitive Wrappers

Immutable Math

Java Time API (JSR-310)

Enums

The final Keyword

Records

How to Achieve Immutability

Common Practices

Chapter 5. Working with Records

Data Aggregation Types

Tuples

A Simple POJO

From POJO to Immutability

From POJO to Record

Records to the Rescue

Behind the Scenes

Record Features

Missing Features

Use Cases and Common Practices

Record Validation and Data Scrubbing

Increasing Immutability

Creating Modified Copies

Records as Local Nominal Tuples

Better Optional Data Handling

Serializing Evolving Records

Record Pattern Matching (Java 19+)

Final Thoughts on Records

Chapter 6. Data Processing with Streams

Data Processing with Iteration

External Iteration

Internal Iteration

Streams as Functional Data Pipelines

Stream Features

Spliterator, the Backbone of Streams

Building Stream Pipelines

Creating a Stream

Doing the Work

Terminating the Stream

Notes:

OCLC-licensed vendor bibliographic record.

Includes index.

ISBN:

9781098109912

1098109910

OCLC:

1378930611