Interfaces versus Abstract classes : pre and post Java 8

I have been given a contract to implement in Java. As a developer one of the early design decisions needed is, do I want an interface or an abstract class at the base of my hierarchy. This question is very popular in the Java world and often always pops up when doing low level design.

Suppliers in Java Lambda World

In the previous post I had a look at Consumer function objects and how they were used in the forEach method of the Iterable class. An exactly opposite kind of interface to the Consumer is the Supplier interface. (like the name doesn't give it away)

Consumers in Java Lambda World

A I mentioned in the previous post, Lambda expressions have helped simplify Collection use cases. We saw that with sorting a Collection. Let me explore some more simplifications in this post.

Lambda

This is kind of late - very late, but then like always - better late than never. So while java lovers world over have dug deep, praised, criticized and in some cases confused the developer community about Lambda expressions in Java 8, I have finally woken and decided to throw my two cents into the pit.
I was kinda too busy/lazy until I got a code review that used Lambdas. With no escape but to review it, I had to start learning Lambdas.  This post is a collection of thoughts I found online and like always just my ready notes to be available for me to refer back when the next code review comes around. With that time to get started.....