Swift中API调用的JSON解析错误域=NSCocoaErrorDomain代码=4865

Question

我正在尝试从Yelp fusion API获取并解析JSON。每当我把它拉进来，试图解析它并将其存储为一个结构时，我都会得到以下错误：

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?
}

以下是从API检索到的JSON数据示例：

{
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" = "[phone]";
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 = "[phone]";
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" = "[phone]";
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 = "[phone]";
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" = "[phone]";
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 = "[phone]";
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" = "[phone]";
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 = "[phone]";
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，这里是我用来调用API并解析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()

我不知道为什么我会收到这个错误，所以任何帮助都将不胜感激。

Answer 1

您需要将businesses数组声明为如下所示的Optional，

let businesses: [Business]?

在声明Optional的非可选数组的所有其他地方也要执行相同的操作，例如

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