json - Error Domain=NSCocoaErrorDomain Code=4865 在 Swift 中从 API 调用解析 JSON

Question

我正在尝试从 Yelp 融合 API 中提取并解析 JSON。每当我将其拉入并尝试解析它并将其存储为结构时，我都会收到以下错误:

    Error Domain=NSCocoaErrorDomain Code=4865 "No value associated with key
CodingKeys(stringValue: "businesses", intValue: nil) ("businesses")." 
UserInfo={NSCodingPath=(), NSDebugDescription=No value associated with key
CodingKeys(stringValue: "businesses", intValue: nil) ("businesses").}

这是我正在使用的结构:

struct BusinessInfo: Codable {
let total: Int?
let businesses: [Business?]

struct Business: Codable{
    let alias: String?
    let categories: [Category?]
    let coordinates: Coordinates?
    let display_phone: String?
    let distance: Double?
    let id: String?
    let image_url: String?
    let is_closed: Bool?
    let location: Location?
    let name: String?
    let phone: String?
    let price: String?
    let rating: Double?
    let review_count: Int?
    let transactions: [String?]
    let url: String?

    struct Category: Codable{
        let alias: String?
        let title: String?
    }

    struct Coordinates: Codable {
        let latitude: Double?
        let longitude: Double?
    }

    struct Location: Codable {
        let address1: String?
        let address2: String?
        let address3: String?
        let city: String?
        let country: String?
        let display_address: [String?]
        let state: String?
        let zip_code: String?
    }
}

struct Region: Codable{
    let center: Center?
    struct Center: Codable{
        let latitude: Double?
        let longitude: Double?
    }
}

let region: Region?
}

这是从 API 检索到的 JSON 数据的示例:

{
businesses =     (
            {
        alias = "the-dixie-cafe-and-quick-stop-keene-2";
        categories =             (
                            {
                alias = grocery;
                title = Grocery;
            },
                            {
                alias = irish;
                title = Irish;
            },
                            {
                alias = "breakfast_brunch";
                title = "Breakfast & Brunch";
            }
        );
        coordinates =             {
            latitude = "37.9434876171571";
            longitude = "-84.6388373202724";
        };
        "display_phone" = "(859) 885-0191";
        distance = "6936.03023671068";
        id = HG6c8zhWHwn0PF9VdzuQug;
        "image_url" = "https://s3-media2.fl.yelpcdn.com/bphoto/R26qmiZSmlIqeQmI17HHvQ/o.jpg";
        "is_closed" = 0;
        location =             {
            address1 = "108 Keene-south Elkhorn Rd";
            address2 = "";
            address3 = "";
            city = Keene;
            country = US;
            "display_address" =                 (
                "108 Keene-south Elkhorn Rd",
                "Keene, KY 40339"
            );
            state = KY;
            "zip_code" = 40339;
        };
        name = "The Dixie Cafe & Quick Stop";
        phone = "+18598850191";
        price = "$$";
        rating = 5;
        "review_count" = 11;
        transactions =             (
        );
        url = "https://www.yelp.com/biz/the-dixie-cafe-and-quick-stop-keene-2?adjust_creative=aTZyFL2LRvYFp-zGww4qKQ&utm_campaign=yelp_api_v3&utm_medium=api_v3_business_search&utm_source=aTZyFL2LRvYFp-zGww4qKQ";
    },
            {
        alias = "family-tree-cafe-nicholasville";
        categories =             (
                            {
                alias = tradamerican;
                title = "American (Traditional)";
            },
                            {
                alias = waffles;
                title = Waffles;
            },
                            {
                alias = tacos;
                title = Tacos;
            }
        );
        coordinates =             {
            latitude = "37.8671798064261";
            longitude = "-84.5775691582197";
        };
        "display_phone" = "(859) 241-1960";
        distance = "3689.465625212305";
        id = nf6NYpdzbyeqEwi6RePH4A;
        "image_url" = "https://s3-media1.fl.yelpcdn.com/bphoto/wufUljZvejj3wQJwESUiOw/o.jpg";
        "is_closed" = 0;
        location =             {
            address1 = "912 S Main St";
            address2 = "";
            address3 = "<null>";
            city = Nicholasville;
            country = US;
            "display_address" =                 (
                "912 S Main St",
                "Nicholasville, KY 40356"
            );
            state = KY;
            "zip_code" = 40356;
        };
        name = "Family Tree Cafe";
        phone = "+18592411960";
        rating = 5;
        "review_count" = 5;
        transactions =             (
        );
        url = "https://www.yelp.com/biz/family-tree-cafe-nicholasville?adjust_creative=aTZyFL2LRvYFp-zGww4qKQ&utm_campaign=yelp_api_v3&utm_medium=api_v3_business_search&utm_source=aTZyFL2LRvYFp-zGww4qKQ";
    },
            {
        alias = "euro-wine-bar-nicholasville";
        categories =             (
                            {
                alias = tapas;
                title = "Tapas Bars";
            },
                            {
                alias = "wine_bars";
                title = "Wine Bars";
            }
        );
        coordinates =             {
            latitude = "37.880196";
            longitude = "-84.5729947";
        };
        "display_phone" = "(859) 885-3139";
        distance = "3585.476417284776";
        id = "4jXOuifkG-qrcII4nnuERQ";
        "image_url" = "https://s3-media3.fl.yelpcdn.com/bphoto/9PdiSt2jv5DpbGQzFeVeeQ/o.jpg";
        "is_closed" = 0;
        location =             {
            address1 = "102 S Main St";
            address2 = "<null>";
            address3 = "<null>";
            city = Nicholasville;
            country = US;
            "display_address" =                 (
                "102 S Main St",
                "Nicholasville, KY 40356"
            );
            state = KY;
            "zip_code" = 40356;
        };
        name = "Euro Wine Bar";
        phone = "+18598853139";
        price = "$$";
        rating = 5;
        "review_count" = 18;
        transactions =             (
        );
        url = "https://www.yelp.com/biz/euro-wine-bar-nicholasville?adjust_creative=aTZyFL2LRvYFp-zGww4qKQ&utm_campaign=yelp_api_v3&utm_medium=api_v3_business_search&utm_source=aTZyFL2LRvYFp-zGww4qKQ";
    },
            {
        alias = "big-city-pizza-nicholasville";
        categories =             (
                            {
                alias = pizza;
                title = Pizza;
            },
                            {
                alias = "chicken_wings";
                title = "Chicken Wings";
            },
                            {
                alias = desserts;
                title = Desserts;
            }
        );
        coordinates =             {
            latitude = "37.8712845368836";
            longitude = "-84.57573077733009";
        };
        "display_phone" = "(859) 885-0111";
        distance = "3621.562736763683";
        id = "q_qps8wM2iJL5BQvrliDcQ";
        "image_url" = "https://s3-media1.fl.yelpcdn.com/bphoto/UWRkMK82sAhX0qf0qYujAQ/o.jpg";
        "is_closed" = 0;
        location =             {
            address1 = "114 Williams Rd";
            address2 = "<null>";
            address3 = "";
            city = Nicholasville;
            country = US;
            "display_address" =                 (
                "114 Williams Rd",
                "Nicholasville, KY 40356"
            );
            state = KY;
            "zip_code" = 40356;
        };
        name = "Big City Pizza";
        phone = "+18598850111";
        price = "$";
        rating = "4.5";
        "review_count" = 30;
        transactions =             (
            delivery,
            pickup
        );
        url = "https://www.yelp.com/biz/big-city-pizza-nicholasville?adjust_creative=aTZyFL2LRvYFp-zGww4qKQ&utm_campaign=yelp_api_v3&utm_medium=api_v3_business_search&utm_source=aTZyFL2LRvYFp-zGww4qKQ";
    }
);
region =     {
    center =         {
        latitude = "37.8844";
        longitude = "-84.6135";
    };
};
total = 4;
}

最后，这是我用来调用 API 和解析 JSON 的代码:

let latitude = currentLocation?.latitude
let longitude = currentLocation?.longitude
let apikey = yelpAPIKey
let url = URL(string: "https://api.yelp.com/v3/businesses/search?term=food&latitude=\(String(describing: latitude))&longitude=\(String(describing: longitude))")
 var request = URLRequest(url: url!)
 request.setValue("Bearer \(apikey)", forHTTPHeaderField: "Authorization")
        request.httpMethod = "GET"
        //Get JSON from Yelp API
        let task = URLSession.shared.dataTask(with: request){ (data, response, error) in
            guard let yelpData = data,
                error == nil else{
                    print(error?.localizedDescription ?? "Response Error")
                    return
            }
            do{
                //Decode the recieved JSON into a BusinessInfo struct
                let result = try JSONDecoder().decode(BusinessInfo.self, from: yelpData)
                APIBusinessInfo.shared = result
            } catch let parsingError as NSError{
                //print(yelpData)
                print("Error:", parsingError)
            }
        }
        task.resume()

我不确定为什么会收到此错误，因此我们将不胜感激。

Answer 1

您需要将 businesses 数组声明为如下所示的 Optional，

let businesses: [Business]?

在声明非可选数组 Optional 的所有其他地方也做同样的事情，例如，

let categories: [Category]? // instead of let categories: [Category?]
let transactions: [String]? // instead of let transactions: [String?]