This blog post should start with a popular quote:
Tony Hoare introduced
nullreferences in ALGOL W back in 1965 “simply because it was so easy to implement”, says Mr. Hoare. He talks about that decision considering it “my billion-dollar mistake”.
Instead of dealing with null / not-null references, Java 8 JDK ships with new type: Optional<T>. How to use it?
Let's see a simple example of Java 8 Stream::flatMap method found in the Stream API. Definition of flatMap in the API doc is:
Right after blog post covering Stream.flatMap() operator, we'll also cover another important Stream operator called - reduce. We'll go straight away with an example.
Say we have a simple Person Java Bean:
In computer programming, the strategy pattern (also known as the policy pattern) is a software design pattern that enables an algorithm's behavior to be selected at runtime. The strategy pattern. defines a family of algorithms, encapsulates each algorithm, and. makes the algorithms interchangeable within that family.
