Resilience4j is a fault tolerance library designed for Java8 and functional programming
VAVR (formerly called Javaslang) is a non-commercial, non-profit object-functional library that runs with Java 8+. It aims to reduce the lines of code and increase code quality.
jOOλ - The Missing Parts in Java 8 jOOλ improves the JDK libraries in areas where the Expert Group's focus was elsewhere. It adds tuple support, function support, and a lot of additional functionality around sequential Streams. The JDK 8's main efforts (default methods, lambdas, and the Stream API) were focused around maintaining backwards compatibility and implementing a functional API for parallelism.
Functional programming in Java
Functional patterns for Java
Code, exercises and solutions from the book "Functional Programming in Java"
java port of Underscore.js
Immutable Collections and Functional Transformations for the JVM