从json解析三个对象的数组

Question

我有 3 个对象（国籍、服务和包），我从 JSON 响应中获取它们作为这些对象的 3 个数组。我想从 JSON 响应中解析它们...

类是：

struct Root2 : Decodable {
let nationalities : [Nationalities]
let services : [Services]
let packages : [Packages]
}

struct Packages : Decodable {
let id: Int
let name: String
let idService: Int
let nationality: String
let totalPrice: Int
let visitsPerWeek: Int
let excludedDays: String
let excludedShifts: String
let excludedDates: String
let extraVisits: Int
let dateEnabled: String
let dateDisabled: String
let allowedFrom: String
let allowedTo: String
let visitType: String
let createdAt: String?
let updatedAt: String?
 }
 struct Nationalities : Decodable{
let id: Int
let name: String
let createdAt: String?
let updatedAt: String?
}
struct Services : Decodable{
let id: Int
let name, description: String
let createdAt: String?
let updatedAt: String?
}

我每个人都有另一个类，例如：

class Service : NSObject, NSCoding {
var id: Int
var name, desc: String
var createdAt: String?
var updatedAt: String?


init(id: Int, name: String, desc: String) {
    self.id = id
    self.name = name
    self.desc = desc

}

required convenience init(coder aDecoder: NSCoder) {
    let id = aDecoder.decodeInteger(forKey: "id")
    let name = aDecoder.decodeObject(forKey: "name") as! String
    let desc = aDecoder.decodeObject(forKey: "desc") as! String
    self.init(id: id, name: name, desc: desc)
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(id, forKey: "id")
    aCoder.encode(name, forKey: "name")
    aCoder.encode(desc, forKey: "desc")
}

}

我是这样使用它的：

 func GetServicesPackagesNationalities(){

let link: String = "my link"
guard let url = URL(string: link) else {
    print("Error: cannot create URL")
    return
}
let urlRequest = URLRequest(url: url)

let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)

let task = session.dataTask(with: urlRequest) {
    (data, response, error) in
    guard error == nil else {
        print("error calling GET on /public/api/services")
        print(error!)
        return
    }
    guard let responseData = data else {
        print("Error: did not receive data")
        return
    }
    do {

        let decoder = JSONDecoder()
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        let result = try decoder .decode(Root2.self, from: responseData)


        var nationalities = [Nationality]()
        for nationality in result.nationalities{
            let newnationality = Nationality(id: nationality.id, name: nationality.name)
            nationalities.append(newnationality)
            print(newnationality.name)
        }


        var services = [Service]()
        for service in result.services {
            let newservice = Service(id: service.id, name: service.name, desc: service.description)
            services.append(newservice)
            print(newservice.name)
        }


       var packages = [Package]()
        for package in result.packages{
            let newpackage = Package(id: package.id, name: package.name, idService: package.idService, nationality: package.nationality, totalPrice: package.totalPrice, visitsPerWeek: package.visitsPerWeek, excludedDays: package.excludedDays, excludedShifts: package.excludedShifts, excludedDates: package.excludedDates, extraVisits: package.extraVisits ,dateEnabled: package.dateEnabled , dateDisabled: package.dateDisabled, allowedFrom: package.allowedFrom, allowedTo: package.allowedTo ,visitType: package.visitType)
            packages.append(newpackage)
            print(newpackage.name)
        }



    }catch  {
        print("error trying to convert data to JSON")
        return
    }
}
task.resume()
 }

我永远都会得到这个：

尝试将数据转换为 JSON 时出错

我的 json 是：

   {
"nationalities": [
    {
        "id": 1,
        "name": "Saudi Arabia",
        "created_at": "2018-04-24 05:50:41",
        "updated_at": "2018-04-24 06:35:29",
        "deleted_at": null
    },
    {
        "id": 2,
        "name": "Bahrain",
        "created_at": "2018-04-24 05:52:52",
        "updated_at": "2018-04-24 05:52:52",
        "deleted_at": null
    },
],
"services": [
    {
        "id": 1,
        "name": "Nad",
        "description": "Nad ",
        "created_at": null,
        "updated_at": null,
        "deleted_at": null
    },
    {
        "id": 2,
        "name": "Reay",
        "description": "Re ",
        "created_at": null,
        "updated_at": null,
        "deleted_at": null
    },
],
"packages": [
    {
        "id": 1,
        "name": "Gold Package",
        "id_service": 1,
        "nationality": "4",
        "total_price": 1000,
        "visits_per_week": 2,
        "excluded_weekdays": "null",
        "excluded_shifts": "null",
        "excluded_dates": "1111-11-11",
        "extra_visits": 1,
        "date_enabled_from": "2018-04-01",
        "date_enabled_to": "2018-04-30",
        "date_allowed_from": "2018-04-05",
        "date_allowed_to": "2018-04-30",
        "visit_type": "Multi",
        "created_at": "2018-04-26 11:18:45",
        "updated_at": "2018-04-26 11:18:45",
        "deleted_at": null
    }
]
}

我不知道我做错了什么..因为我对两个对象进行了相同的尝试并且工作正常..

谁能告诉我我做错了什么？

在用户默认值中使用它们：

存储：

     let userDefaults = UserDefaults.standard


        let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: services)
        userDefaults.set(encodedData, forKey: "services")
        userDefaults.synchronize()

检索：

        let decoded  = userDefaults.object(forKey: "services") as! Data
        let decodedService = NSKeyedUnarchiver.unarchiveObject(with: decoded) as! [Service]

        for service in decodedService {
            print(service.name)
        }

Answer 1

请永远不要在 catch 子句中打印无意义的文字字符串，始终打印实际的错误，它会告诉您究竟出了什么问题

} catch  {
    print(error)
}

---

Package 有很多问题，这里是错误消息（以及修复它们的建议）：

"没有与键 CodingKeys 关联的值(stringValue: \"excludedDays\"，转换为excluded_days。"

• JSON 中没有键 excluded_days。 删除该属性或将其声明为可选 (String?)

"没有与键 CodingKeys 关联的值(stringValue: \"dateEnabled\" 转换为 date_enabled。"

• 实际的snake_case转换属性应该是dateEnabledFrom

"没有与键 CodingKeys 关联的值(stringValue: \"dateDisabled\" 转换为 date_disabled。"

• JSON 中没有键 date_disabled。 删除该属性或将其声明为可选 (String?)

"没有与键 CodingKeys 关联的值(stringValue: \"allowedFrom\", intValue: nil) (\"allowedFrom\")，转换为allowed_from。"

• 实际的snake_case 转换属性应该是dateAllowedFrom

"没有与键 CodingKeys 关联的值(stringValue:\"allowedTo\", intValue: nil) (\"allowedTo\")，转换为allowed_to。"

• 实际的snake_case转换属性应该是dateAllowedTo

---

注意：

你为什么要为Nationality, Service, Package 使用另一个额外的类？它们似乎是多余的。如果您确实需要引用语义，请将 JSON 解码为类。

Answer 2

查看Nationality 和Nationalities 之间的区别

您应该使用Nationalities 来解析您的 JSON 响应。

你应该这样做，因为你已经在 Root2 中声明了 Nationalities 对象

var nationalities = [Nationalities]()
for nationality in result.nationalities{
    let newnationality = Nationalities(id: nationality.id, name: nationality.name)
    nationalities.append(newnationality)
    print(newnationality.name)
}

Services 和 Packages 相同，请查找。