微信小程序二手交易平台订单界面的建造者模式（Builder）Java代码实现

在微信小程序二手交易平台中，订单界面的建造者模式（Builder）可以用以下Java代码实现：

首先，我们需要定义一个订单类（Order），它包含订单的各个属性：

public class Order {
    private String orderId;
    private String buyerName;
    private String sellerName;
    private String itemName;
    private double itemPrice;
    private String itemDescription;
    private String shippingAddress;

    public Order(String orderId) {
        this.orderId = orderId;
    }

    public void setBuyerName(String buyerName) {
        this.buyerName = buyerName;
    }

    public void setSellerName(String sellerName) {
        this.sellerName = sellerName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public void setItemPrice(double itemPrice) {
        this.itemPrice = itemPrice;
    }

    public void setItemDescription(String itemDescription) {
        this.itemDescription = itemDescription;
    }

    public void setShippingAddress(String shippingAddress) {
        this.shippingAddress = shippingAddress;
    }

    // getters omitted for brevity
}

接下来，我们定义一个订单构建器接口（OrderBuilder），它规定了构建订单所需的各个方法：

public interface OrderBuilder {
    void setBuyerName(String buyerName);
    void setSellerName(String sellerName);
    void setItemName(String itemName);
    void setItemPrice(double itemPrice);
    void setItemDescription(String itemDescription);
    void setShippingAddress(String shippingAddress);
    Order getOrder();
}

然后，我们创建一个具体的订单构建器类（ConcreteOrderBuilder），它实现了订单构建器接口，负责构建订单对象：

public class ConcreteOrderBuilder implements OrderBuilder {
    private Order order;

    public ConcreteOrderBuilder(String orderId) {
        order = new Order(orderId);
    }

    @Override
    public void setBuyerName(String buyerName) {
        order.setBuyerName(buyerName);
    }

    @Override
    public void setSellerName(String sellerName) {
        order.setSellerName(sellerName);
    }

    @Override
    public void setItemName(String itemName) {
        order.setItemName(itemName);
    }

    @Override
    public void setItemPrice(double itemPrice) {
        order.setItemPrice(itemPrice);
    }

    @Override
    public void setItemDescription(String itemDescription) {
        order.setItemDescription(itemDescription);
    }

    @Override
    public void setShippingAddress(String shippingAddress) {
        order.setShippingAddress(shippingAddress);
    }

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

最后，我们创建一个订单指挥者类（OrderDirector），它负责组合订单构建器以构建订单对象：

public class OrderDirector {
    public Order constructOrder(OrderBuilder builder, String buyerName, String sellerName,
                                String itemName, double itemPrice, String itemDescription,
                                String shippingAddress) {
        builder.setBuyerName(buyerName);
        builder.setSellerName(sellerName);
        builder.setItemName(itemName);
        builder.setItemPrice(itemPrice);
        builder.setItemDescription(itemDescription);
        builder.setShippingAddress(shippingAddress);
        return builder.getOrder();
    }
}

这样，我们就可以使用建造者模式构建订单对象：

OrderBuilder builder = new ConcreteOrderBuilder("123456");
OrderDirector director = new OrderDirector();
Order order = director.constructOrder(builder, "John Doe", "Jane Smith",
        "Used iPhone XS Max", 800.0, "A few scratches but works perfectly",
        "123 Main St, Anytown, USA");