15.6 构建复杂模型

package chapter15._6;

import chapter15._3.coffee.Generator;
import chapter15._4._3.Generators;
import com.sun.tools.javac.comp.Check;

import java.util.ArrayList;
import java.util.Random;

class Product {

    private final int id;
    private String description;
    private double price;

    public Product(int id, String description, double price) {
        this.id = id;
        this.description = description;
        this.price = price;
//        System.out.println(toString());
    }

    public String toString() {
        return id + ": " + description + ". price: $" + price;
    }

    public void changePrice(double change) {
        price += change;
    }

    public static Generator<Product> generator = new Generator<Product>() {
        private Random random = new Random(47);
        @Override
        public Product next() {
            return new Product(
                    random.nextInt(1000),
                    "Test",
                    Math.round(random.nextDouble() * 1000.0) + 0.99
            );
        }
    };
}

class Shelf extends ArrayList<Product> {
    public Shelf(int nProducts) {
        Generators.fill(this, Product.generator, nProducts);
    }
}

class Aisle extends ArrayList<Shelf> {
    public Aisle(int nShelves, int nProducts) {
        for (int i = 0; i < nShelves; i++)
            add(new Shelf(nProducts));
    }
}

class CheckoutStand {}
class Office {}

public class Store extends ArrayList<Aisle> {

    private ArrayList<CheckoutStand> checkoutStands = new ArrayList<CheckoutStand>();
    private Office office = new Office();

    public Store(int nAisles, int nShelfs, int nProducts) {
        for (int i = 0; i < nAisles; i++)
            add(new Aisle(nShelfs, nProducts));
    }

    public String toString() {
        StringBuilder result = new StringBuilder();
        for (Aisle a : this) {
            for (Shelf s : a) {
                for (Product p : s) {
                    result.append(p);
                    result.append("\n");
                }
            }
        }
        return result.toString();
    }

    public static void main(String[] args) {
        Store store = new Store(3,2,2);
        System.out.println(store);
    }
}

输出

258: Test. price: 160.99
868: Test. price: 268.99
551: Test. price: 804.99
520: Test. price: 530.99
704: Test. price: 24.99
674: Test. price: 484.99