如何解组请求中返回的JSON？

Question

I'm attempting to use the USDA's Farmers Market Directory API to receive a data about where nearby farmer's markets are located, using a zip code. I store the unmarshalled body of the response in:

type marketResponse struct {
        MapsLink string `json:"GoogleLink"`
        Address  string `json:"Address"`
        Schedule string `json:"Schedule"`
        Products string `json:"Products"`
}

Using the code:

//TODO: location: "http://search.ams.usda.gov/farmersmarkets/v1/data.svc/locSearch?lat=" + lat + "&lng=" + lng
resp, err := http.Get("http://search.ams.usda.gov/farmersmarkets/v1/data.svc/zipSearch?zip=" + zipcode)
if err != nil {
        log.Printf("Could net search zipcode %s: %v", zipcode, err)
}
defer func() {
        if err := resp.Body.Close(); err != nil {
                log.Println(err)
        }
}()

body, err := ioutil.ReadAll(resp.Body)
if err != nil {
        log.Println(err)
}

newMarket := &marketResponse{}
if err := json.Unmarshal(body, newMarket); err != nil {
        log.Println(err)
}

log.Println("response: " + newMarket.Address)

The problem is, the response body is in JSONp, and I'm unmarshalling in JSON. How can I unmarshal in JSONp, using an external package, or not?

Answer 1

The response body is JSON - as per the response's Content-Type:application/json; charset=utf-8 header.

The issue is that your marketResponse struct bears no relation to the JSON returned. Using JSON-to-Go, your struct should look like:

type MarketResponse struct {
    Results []Result `json:"results"`
}

type Result struct {
    ID string `json:"id"`
    Marketname string `json:"marketname"`
}

It's not clear where your existing marketResponse struct fits here, as neither API endpoint returns data with that structure.

PS: You should handle (or return) your errors and not just log them; logging them still means that your function continues with unhandled error. Your code might then panic when it encounters a nil response body or JSON unmarshalling error.