Java 8 / did U know?

JavaScript engine

Engine Nashorn replaces old one (Rhino) as the new default JavaScript engine for the Oracle jvm. Nashorn is faster. It uses the invokedynamic feature of the jvm. "jjs" is Nashorn command line tool.

Optional

8 comes with the Optional class (java.util.Optional) for avoiding nulls (NullPointerException). It is very similar to Google’s Optional, which is similar to Nat Pryce’s Maybe or Scala’s Option class.

Streams

What is a Stream? Stream is a interface (java.util.stream.Stream) and represents a sequence of some objects. However, unlike the Iterator, it supports parallel execution. The Stream supports the map/filter/reduce design pattern and executes lazily, forming the basis (along with lambdas) for functional-style programming in Java 8.


Example:
// finding a maximum
max = list.stream().reduce(0.0, Math::max);