Creating streams

Streams can be of fixed or infinite length. In the previous example, we used an array of integers to create a fixed length stream. However, if we want to process data arriving through a network connection, this stream of data may appear to be infinite. We can create both types of streams in Java 8.

We will use a Rectangle class to demonstrate the use of streams in several sections of this chapter. The class possesses position and dimension variables and three methods:

• scale: This changes the size of a rectangle

• getArea: This returns its area

• toString: This displays its values

The class declaration follows:

public class Rectangle {
    private int x;
    private int y;
    private int height;
    private int width;

    public Rectangle(int x, int y, int height, int width) {
        this.x = x;
        this.y = y;
        this.height = height;
        this.width = width;
    }
    
    public Rectangle scale(double percent) {
        height = (int) (height * (1.0 + percent)...