json - 在 Go 中循环嵌套的 JSON 元素

Question

我从包含一个或多个“实体”的 API 收到 JSON 响应。 JSON 看起来像这样:

{
    "3211": {
        "entity_id": "3211",
        "status": "complete",
        "coupon_code": "COUPON",
        "shipping_description": "Shipping - AU Courier",
        "customer_id": "2775",
        "base_discount_amount": "-50.0000",
        "base_grand_total": "149.0000",
        "base_shipping_amount": "0.0000",
        "base_shipping_tax_amount": "0.0000",
        "base_subtotal": "199.0000",
        "base_tax_amount": "0.0000",
        "base_total_paid": "149.0000",
        "base_total_refunded": null,
        "discount_amount": "-50.0000",
        "grand_total": "149.0000",
        "shipping_amount": "0.0000",
        "shipping_tax_amount": "0.0000",
        "store_to_order_rate": "1.0000",
        "subtotal": "199.0000",
        "tax_amount": "0.0000",
        "total_paid": "149.0000",
        "total_refunded": null,
        "base_shipping_discount_amount": "0.0000",
        "base_subtotal_incl_tax": "199.0000",
        "base_total_due": "0.0000",
        "shipping_discount_amount": "0.0000",
        "subtotal_incl_tax": "199.0000",
        "total_due": "0.0000",
        "increment_id": "200000423",
        "base_currency_code": "AUD",
        "discount_description": "COUPON",
        "remote_ip": "123.123.123.123",
        "store_currency_code": "AUD",
        "store_name": "Australia",
        "created_at": "2017-07-17 03:07:40",
        "shipping_incl_tax": "0.0000",
        "payment_method": "ewayrapid_ewayone",
        "gift_message_from": null,
        "gift_message_to": null,
        "gift_message_body": null,
        "tax_name": null,
        "tax_rate": null,
        "addresses": [
            {
                "region": "South Australia",
                "postcode": "5000",
                "lastname": "Doe",
                "street": "Level 6\n25 Example Street",
                "city": "Adelaide",
                "email": "example@email.com",
                "telephone": "+61 123 456 789",
                "country_id": "AU",
                "firstname": "John",
                "address_type": "billing",
                "prefix": null,
                "middlename": null,
                "suffix": null,
                "company": null
            },
            {
                "region": "South Australia",
                "postcode": "5000",
                "lastname": "Doe",
                "street": "Level 6\n25 Example Street",
                "city": "Adelaide",
                "email": "example@email.com",
                "telephone": "+61 123 456 789",
                "country_id": "AU",
                "firstname": "John",
                "address_type": "shipping",
                "prefix": null,
                "middlename": null,
                "suffix": null,
                "company": null
            }
        ]
    }
}

我编写了以下struct 类型:

type Orders map[string]Order
type Order struct {
    EntityID                   string                    `json:"entity_id"`
    Status                     string                    `json:"status"`
    CouponCode                 string                    `json:"coupon_code"`
    ShippingDescription        string                    `json:"shipping_description"`
    CustomerID                 string                    `json:"customer_id"`
    BaseDiscountAmount         string                    `json:"base_discount_amount"`
    BaseGrandTotal             string                    `json:"base_grand_total"`
    BaseShippingAmount         string                    `json:"base_shipping_amount"`
    BaseShippingTaxAmount      string                    `json:"base_shipping_tax_amount"`
    BaseSubtotal               string                    `json:"base_subtotal"`
    BaseTaxAmount              string                    `json:"base_tax_amount"`
    BaseTotalPaid              string                    `json:"base_total_paid"`
    BaseTotalRefunded          string                    `json:"base_total_refunded"`
    DiscountAmount             string                    `json:"discount_amount"`
    GrandTotal                 string                    `json:"grand_total"`
    ShippingAmount             string                    `json:"shipping_amount"`
    ShippingTaxAmount          string                    `json:"shipping_tax_amount"`
    StoreToOrderRate           string                    `json:"store_to_order_rate"`
    Subtotal                   string                    `json:"subtotal"`
    TaxAmount                  string                    `json:"tax_amount"`
    TotalPaid                  string                    `json:"total_paid"`
    TotalRefunded              string                    `json:"total_refunded"`
    BaseShippingDiscountAmount string                    `json:"base_shipping_discount_amount"`
    BaseSubtotalInclTax        string                    `json:"base_subtotal_incl_tax"`
    BaseTotalDue               string                    `json:"base_total_due"`
    ShippingDiscountAmount     string                    `json:"shipping_discount_amount"`
    SubtotalInclTax            string                    `json:"subtotal_incl_tax"`
    TotalDue                   string                    `json:"total_due"`
    IncrementID                string                    `json:"increment_id"`
    BaseCurrencyCode           string                    `json:"base_currency_code"`
    DiscountDescription        string                    `json:"discount_description"`
    RemoteIP                   string                    `json:"remote_ip"`
    StoreCurrencyCode          string                    `json:"store_currency_code"`
    StoreName                  string                    `json:"store_name"`
    CreatedAt                  string                    `json:"created_at"`
    ShippingInclTax            string                    `json:"shipping_incl_tax"`
    PaymentMethod              string                    `json:"payment_method"`
    TaxName                    string                    `json:"tax_name"`
    TaxRate                    string                    `json:"tax_rate"`
    Addresses                  map[string]OrderAddresses `json:"addresses"`
}

type OrderAddresses []struct {
    Region      string  `json:"region"`
    Postcode    string  `json:"postcode"`
    Lastname    string  `json:"lastname"`
    Street      string  `json:"street"`
    City        string  `json:"city"`
    Email       string  `json:"email"`
    Telephone   string  `json:"telephone"`
    CountryID   string  `json:"country_id"`
    Firstname   string  `json:"firstname"`
    AddressType string  `json:"address_type"`
    Prefix      *string `json:"prefix"`
    Middlename  *string `json:"middlename"`
    Suffix      *string `json:"suffix"`
    Company     *string `json:"company"`
}

然后我尝试像这样处理它(getFromOrdersAPI(page) 函数在 Orders 类型中返回上面提到的 JSON):

for page := 1; page < 3; page++ {
    orders := getFromOrdersAPI(page)
    for _, order := range orders {
        //Process all the order items except addresses
        fmt.Println("Processing entity:", orders.EntityID)

        for _, orderaddress := range order.Addresses {
            //Trying to access address values - example below
            fmt.Println(orderaddress.Region)
        }
    }
}

运行时出现错误:

orderaddress.Region undefined (type OrderAddresses has no field or method Region)

我哪里错了？

Answer 1

您收到的错误是由于您定义 OrderAddresses 结构的方式所致。而不是

type OrderAddresses []struct {

如果你使用

type OrderAddresses struct {

没有大括号，你的编译错误应该会消失。

也就是说，鉴于我正在查看的 blob，我不确定您的 json 是否会按照您的预期进行解析。看来 json blob 中的 addresses 是一个数组。这意味着不是将其表示为

Addresses map[string]OrderAddresses `json:"addresses"`

您应该简单地将其作为 OrderAddresses 的一部分

Addresses []OrderAddresses `json:"addresses"`