Functional Java

Pragmatic Bookshelf

Functional Programming in Java: Harness the Power of Streams and Lambda Expressions

O'Reilly

A Functional Approach to Java: Augmenting Object-Oriented Java Code with Functional Principles

Independently published

Learn Functional Programming The Fast Way!: A former Java/OOP instructor teaches FP in the fastest way he knows

Java Functional Programming: Hands-On (Complete Java course : from ZERO to professional) (English Edition)

O'Reilly UK Ltd.

Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions

Manning Pubns Co

Functional Programming in Scala                  

Manning Publications

Functional Programming in Java: How functional techniques improve your Java programs

ThoughtFlow Solutions inc.

Functional Java: A Guide to Lambdas and Functional Programming in Java 8 (English Edition)

Independently published

Functional Programming with Java: An In-Depth Exploration and Implementation Guide

Independently published

Java Functional Programming - Lambda & Stream Practice Tests: 180+ questions on Inner classes, Lambda expressions, Method References, Functional Interfaces & Stream API