使用java.util.function.Function实现工厂设计模式

import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

interface Product {
    void display();
}

class ConcreteProductA implements Product {
    @Override
    public void display() {
        System.out.println("This is Product A");
    }
}

class ConcreteProductB implements Product {
    @Override
    public void display() {
        System.out.println("This is Product B");
    }
}

class Factory {
    private static final Map<String, Function<Void, Product>> productMap = new HashMap<>();

    static {
        productMap.put("A", (Void) -> new ConcreteProductA());
        productMap.put("B", (Void) -> new ConcreteProductB());
    }

    public static Product createProduct(String type) {
        Function<Void, Product> productFunction = productMap.get(type);
        if (productFunction != null) {
            return productFunction.apply(null);
        }
        throw new IllegalArgumentException("Invalid product type: " + type);
    }
}

public class Main {
    public static void main(String[] args) {
        Product productA = Factory.createProduct("A");
        productA.display();

        Product productB = Factory.createProduct("B");
        productB.display();
    }
}