[Java知识库]创建复杂对象-构造模式

使用场景：生成订单实体的时候，需要对价格，地址，商品等属性赋值

改造前

     public static void main(String[] args) {
        Order order = new Order() ;
        System.out.println("处理收获地址业务逻辑");
        order.setAccount("张三");
        System.out.println("根据优惠券计算订单价格");

    }

改造后

1. 对象的创建和属性赋值都通过接口来实现

    public interface OrderBuilder{
        public OrderBuilder setAccount(String account) ;
        public OrderBuilder setAddress() ;
        public OrderBuilder setPrice() ;
        Order create();
    }

2.实现接口

 public class OrderBuilderImpl implements OrderBuilder{

        private Order order = new Order() ;
        @Override
        public OrderBuilder setAddress() {
            System.out.println("处理收获地址业务逻辑");
            return this ;
        }

        @Override
        public OrderBuilder setPrice() {
            System.out.println("根据优惠券计算订单价格");
            return this ;
        }

        @Override
        public Order create() {
            return order ;
        }
    }

?3.创建对象

    public static void main(String[] args) {
         OrderBuilder order = new OrderBuilderImpl()
                 .setAccount("张三")
                 .setAddress()
                 .setPrice()
                 .create() ;
    }