// patterns/ShapeFactory3.java

// (c)2021 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// Polymorphic factory methods.

import java.util.*;

import java.util.function.*;

import java.util.stream.*;

import patterns.shapes.*;

interface PolymorphicFactory {

Shape create();

}

class RandomShapes implements Supplier<Shape> {

private final PolymorphicFactory[] factories;

private Random rand = new Random(42);

RandomShapes(PolymorphicFactory... factories) {

this.factories = factories;

}

@Override public Shape get() {

return

factories[rand.nextInt(factories.length)]

.create();

}

}

public class ShapeFactory3 {

public static void main(String[] args) {

RandomShapes rs = new RandomShapes( // [1]

Circle::new, Square::new, Triangle::new

);

Stream.generate(rs)

.limit(6)

.peek(Shape::draw)

.peek(Shape::erase)

.count();

}

}

/* Output:

Triangle[0] draw

Triangle[0] erase

Circle[1] draw

Circle[1] erase

Circle[2] draw

Circle[2] erase

Triangle[3] draw

Triangle[3] erase

Circle[4] draw

Circle[4] erase

Square[5] draw

Square[5] erase

*/