//简单工厂

 class SimpleProductFactory{

     Product createProduct(String type){

         //选择--varied

         if (type.equals("type1")){

             product = new ...

         }else if(...){

             ...

         }else{

             ...

         }

         return product;

     }

 }

 Product orderProduct(String type){

     SimpleProductFactory factory = new SimpleProductFactory();

     Product product = factory.createProduct(type);

     //other operations...

 }

 //进一步封装

 public class ProductStore{

     SimpleProductFactory factory;

     public ProductStore(SimpleProductFactory factory){

         this.factory = factory;

     }

     public Product orderProduct(String type){

         Product product = factory.createProduct(type);

         //other operations...

     }

 }

 /*

 这一步：

 使用了一个Store类，包含了生产产品的方法。

 factory在构造函数的时候传进来。

 推迟了new操作。

 */

 //工厂方法模式

 public abstract class ProductStore{

     public Product orderProduct(String type){

         Product product = createProduct(type);

         //product.test();

         //other methods...

         return product;

     }

     protected abstract Product createProduct; //->工厂方法

     //other methods...

 }

 //抽象工厂模式

 //原料工厂

 public interface ProductIngredientFactory{

     public Ingredient1 createIngredient1();

     public Ingredient2 createIngredient2();

     public Ingredient3 createIngredient3();

     //...

 }

 //具体的原料工厂类

 //实现每一种对应的ingredient

 public class Product1 extends Product{

     ProductIngredientFactory ingredientFactory;

     public Product1(ProductIngredientFactory ingredientFactory){

         this.ingredientFactory = ingredientFactory;

     }

     void prepare(){

         ingredient1 = ingredientFactory.createIngredient1();

         ingredient2 = ingredientFactory.createIngredient2();

         ingredient3 = ingredientFactory.createIngredient3();

     }

 }

 //重构产品商店

 //每个具体的商店（继承自抽象的ProductStore）都要实现里面的工厂方法

 //可能不止createProduct这一种工厂方法

 //在这个工厂方法里，实现具体工厂的实例（包含了多个abstract方法），将具体工厂传入产品中

 public class ProductStore1 extends ProductStore{

     //implement an abstract method

     protected Product createProduct(String type){

         Product product = null;

         ProductIngredientFactory ingredientFactory = new ProductIngredientFactory1(); //指定是原料工厂1，具体的类

         if (type.equals("type1")){

             product = new Product1(ingredientFactory);

         }else if(...){

             ...

         }else{

             ...

         }

         return product;

     }

 }