Java: Data Science Made Easy

Streaming API

Java 8 was a big step forward in the history of the Java language. Among other features, there were two important things--Streams and Lambda expressions.

In Java, a stream is a sequence of objects, and the Streams API provides functional-style operations to transform these sequences, such as map, filter, and reduce. The sources for streams can be anything that contain elements, for example, arrays, collections, or files.

For example, let's create a simple Word class, which contains a token and its part of speech:

public class Word {     private final String token;     private final String pos;     // constructor and getters are omitted }

For brevity, we will always omit constructors and getters for such data classes, but indicate that ...