Java享元设计模式优化对象创建提高性能和效率

public interface Product {
    String getName();
    double getPrice();
    int getStock();
}

public class ConcreteProduct implements Product{
    private String name;
    private double price;
    private int stock;
    public ConcreteProduct(String name, double price, int stock) {
        this.name = name;
        this.price = price;
        this.stock = stock;
    }
    @Override
    public String getName() {
        return name;
    }
    @Override
    public double getPrice() {
        return price;
    }
    @Override
    public int getStock() {
        return stock;
    }
}

public class ProductFactory {
    private static Map<String, Product> productMap = new HashMap<>();
    public static Product getProduct(String name, double price, int stock) {
        String key = name + "_" + price;
        Product res = productMap.get(key);
        if (Objects.isNull(res)) {
            // 如果缓存池内不存在,就创建新对象放置到缓存池
            res = new ConcreteProduct(name, price, stock);
            productMap.put(key, res);
        }
        return res;
    }
}

public class Demo {
    public static void main(String[] args) {
        Product p1 = ProductFactory.getProduct("iPhone 14 Plus", 8899, 1);
        Product p2 = ProductFactory.getProduct("iPhone 14 Plus", 8899, 1);
        System.out.println(p1 == p2);
    }
}