go - 从链接读取JSON

Question

我想返回从此link返回的字符串，并基于返回的数据构建一个JSON对象，我编写了以下代码来读取url并正确获取该字符串，但是它无法构建JSON对象，并且没有返回任何东西!

package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
)

type Product struct {
    ProductId   string `json:"id"`
    ProductName string `json:"description"`
}

func main() {
    url := "https://script.googleusercontent.com/macros/echo?user_content_key=WBSJPDNSN6X1FCYeXsR6TDaDval0vdvmSoMmXFhGbt5sfK0ia80Dp7kPD27GLpZbYz8vrwfDiUecI2oGMjEtgfL5o8Da25T1m5_BxDlH2jW0nuo2oDemN9CCS2h10ox_1xSncGQajx_ryfhECjZEnGb6k9xaGtOX6M1tIiG811CRpk9nXl8ZKS7UJTno1dvQXMe1kqfAj8WxsSkLor-EqzOmbnRGq-tk&lib=M0B6GXYh0EOYMkP7qr1Xy9xw8GuJxFqGH"
    resp, err := http.Get(url)
    if err != nil {
        log.Fatal(err)
    }

    defer resp.Body.Close()

    htmlData, err := ioutil.ReadAll(resp.Body) //<--- here!

    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }

    // print out
    fmt.Println(string(htmlData))

    var product Product
    json.Unmarshal([]byte(string(htmlData)), &product)

    fmt.Printf("ID: %s, Description: %s", product.ProductId, product.ProductName)
}

输出:

{"user":[{"ProductId":1,"ProductName":"Helmet"},{"ProductId":2,"ProductName":"Glove"},{"ProductId":3,"ProductName":"Detecttor"}]}
ID: , Description:

Answer 1

1-解码目标结构必须与数据匹配，

type Data struct {
   User []Product `json:"user"`
}

2-字段类型应该匹配，因此 ProductID应该是 uint3-输出的json OP应该匹配使用的标签， json:"id"应该替换为 json:"ProductId"的 description

type Product struct {
    ProductId   uint `json:"ProductId"`
    ProductName string `json:"ProductName"`
}

因此，一个有效的代码是:

package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
)

type Data struct {
    User []Product `json:"user"`
}
type Product struct {
    ProductId   uint   `json:"ProductId"`
    ProductName string `json:"ProductName"`
}

func main() {
    url := "https://script.googleusercontent.com/macros/echo?user_content_key=WBSJPDNSN6X1FCYeXsR6TDaDval0vdvmSoMmXFhGbt5sfK0ia80Dp7kPD27GLpZbYz8vrwfDiUecI2oGMjEtgfL5o8Da25T1m5_BxDlH2jW0nuo2oDemN9CCS2h10ox_1xSncGQajx_ryfhECjZEnGb6k9xaGtOX6M1tIiG811CRpk9nXl8ZKS7UJTno1dvQXMe1kqfAj8WxsSkLor-EqzOmbnRGq-tk&lib=M0B6GXYh0EOYMkP7qr1Xy9xw8GuJxFqGH"
    resp, err := http.Get(url)
    if err != nil {
        log.Fatal(err)
    }

    defer resp.Body.Close()

    htmlData, err := ioutil.ReadAll(resp.Body) 

    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }

    // print out
    fmt.Println(string(htmlData))

    //var product Product
    var data Data
    json.Unmarshal([]byte(string(htmlData)), &data)

    fmt.Println(data)
    fmt.Println(data.User)
    fmt.Println(data.User[0])
    fmt.Printf("id: %v, description: %s", data.User[0].ProductId, data.User[0].ProductName)
}