swift 解析 json - 無法讀取數據，因為它的格式不正確

Question

這是結構編碼代碼：

import Foundation

public struct TaskID: Codable {
    let embedded: Embedded
}

public struct Embedded: Codable {
    let task: [Task]
}

public struct Task : Codable {

    let embedded: EmbeddedVariable
    let id : String
    let name: String
    let assignee: String
    let created: String
    let processDefinitionId: String
}

public struct EmbeddedVariable: Codable {

    let variable : [Variables]
}

public struct Variables: Codable {

    let value : String
    let name: String
}

我已經嘗試過codingKey，也嘗試過使用_embedded。 面臨同樣的問題。

錯誤日志：由於錯誤無法解碼響應：

 Alamofire.AFError.
 ResponseSerializationFailureReason.decodingFailed(error: Swift.DecodingError.typeMismatch(Swift.Dictionary<Swift.String, Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Dictionary<String, Any> but found an array instead.", underlyingError: nil)))))

無法讀取數據，因為它的格式不正確。

這是 JSONSerialization 的代碼：

      // MARK: - URLRequestConvertible
func asURLRequest() throws -> URLRequest {
    let url = try K.ProductionServer.baseURL.asURL()
    
    var urlRequest = URLRequest(url: url.appendingPathComponent(path))
    print(urlRequest)
    // HTTP Method
    urlRequest.httpMethod = method.rawValue
   
    let authToken = UserDefaults.standard.string(forKey: "authToken")
    let bearerToken: String = "Bearer " + (authToken ?? "")
    print("baearer token::\(bearerToken)")
    
    // Common Headers
    urlRequest.setValue(ContentType.json.rawValue, forHTTPHeaderField: HTTPHeaderField.acceptType.rawValue)
    urlRequest.setValue(ContentType.json.rawValue, forHTTPHeaderField: HTTPHeaderField.contentType.rawValue)
    urlRequest.setValue(bearerToken, forHTTPHeaderField: HTTPHeaderField.authentication.rawValue)
    
    // Parameters
    if let parameters = parameters {
        do {
            urlRequest.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: [])
        } catch {
            throw AFError.parameterEncodingFailed(reason: .jsonEncodingFailed(error: error))
        }
    }
    
    return urlRequest
}

這是代碼 json 返回響應：

   import Foundation
  import Alamofire

public class APIClient {
@discardableResult
private static func performRequest<T:Decodable>(route:APIRouter, decoder: JSONDecoder = JSONDecoder(), completion:@escaping (AFResult<T>)->Void) -> DataRequest {
            
    return AF.request(route)
                    .responseDecodable (decoder: decoder){ (response: AFDataResponse<T>) in
                        completion(response.result)
                        print("framework response::",response.result)
    }
}

public static func taskID(id: String, completion:@escaping (AFResult<MyTaskData>)->Void) {
    
    performRequest(route: APIRouter.TaskById(id: id), completion: completion)
}


}//APIClient

Answer 1

在您的 JSON 有效負載中，關鍵processDefinitionId的值末尾有一個額外的逗號。

試試這個 JSON 格式化工具來驗證 JSON： jsonformatter

"task":[
        {
         //...

         "id": "412a2aca-06ae-11ea-8860-120ef5ab2c25",
         "name": "Quick Evaluation",
         "assignee": "demo",
         "created": "2019-11-14T07:13:27.558+0000",
         "processDefinitionId": "quickEvaluation:1:129ce2b1-0616-11ea-8860-120ef5ab2c25", // remove this coma(,) from this line

        }

更新：

對_embedded CodingKey 試試下面的方法

// MARK: - TaskID
struct TaskID: Codable {
    let embedded: Embedded
    let count: Int

    enum CodingKeys: String, CodingKey {
        case embedded = "_embedded"
        case count
    }
}

// MARK: - Embedded
struct Embedded: Codable {
    let task: [Task]
}

// MARK: - Task
struct Task: Codable {
    let embedded: EmbeddedVariable
    let id, name, assignee, created: String
    let processDefinitionID: String

    enum CodingKeys: String, CodingKey {
        case embedded = "_embedded"
        case id, name, assignee, created
        case processDefinitionID = "processDefinitionId"
    }
}

// MARK: - EmbeddedVariable
struct EmbeddedVariable: Codable {
    let variable: [Variable]
}

// MARK: - Variable
struct Variable: Codable {
    let links: Links
    let name, value, type: String
    let valueInfo: ValueInfo

    enum CodingKeys: String, CodingKey {
        case links = "_links"
        case name, value, type, valueInfo
    }
}

// MARK: - Links
struct Links: Codable {
    let linksSelf: SelfClass

    enum CodingKeys: String, CodingKey {
        case linksSelf = "self"
    }
}

// MARK: - SelfClass
struct SelfClass: Codable {
    let href: String
}

// MARK: - ValueInfo
struct ValueInfo: Codable {
}

Answer 2

在可編碼結構中將所有embeded更改為_embeded怎么樣？

在您的APIClient class 中，默認創建JSONDecoder實例。 並且在解碼過程中不會更改鍵名包括下划線。

JSONDecoder.KeyDecodingStrategy.useDefaultKeys策略是您未指定時使用的策略。 來自 Apple 的文檔

代碼

public struct TaskID: Codable {
    let _embedded: Embedded
}

public struct Task : Codable {

    let _embedded: EmbeddedVariable
    let id : String
    let name: String
    let assignee: String
    let created: String
    let processDefinitionId: String
}

Answer 3

嘗試使用 QuickType.io

// MARK: - Welcome
struct Welcome: Codable {
    let embedded: WelcomeEmbedded
    let count: Int

    enum CodingKeys: String, CodingKey {
        case embedded = "_embedded"
        case count
    }
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseWelcomeEmbedded { response in if let welcomeEmbedded = response.result.value {... } }

// MARK: - WelcomeEmbedded
struct WelcomeEmbedded: Codable {
    let task: [Task]
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseTask { response in if let task = response.result.value {... } }

// MARK: - Task
struct Task: Codable {
    let embedded: TaskEmbedded
    let id, name, assignee, created: String
    let processDefinitionID: String

    enum CodingKeys: String, CodingKey {
        case embedded = "_embedded"
        case id, name, assignee, created
        case processDefinitionID = "processDefinitionId"
    }
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseTaskEmbedded { response in if let taskEmbedded = response.result.value {... } }

// MARK: - TaskEmbedded
struct TaskEmbedded: Codable {
    let variable: [Variable]
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseVariable { response in if let variable = response.result.value {... } }

// MARK: - Variable
struct Variable: Codable {
    let links: Links
    let embedded: JSONNull?
    let name, value, type: String
    let valueInfo: ValueInfo

    enum CodingKeys: String, CodingKey {
        case links = "_links"
        case embedded = "_embedded"
        case name, value, type, valueInfo
    }
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseLinks { response in if let links = response.result.value {... } }

// MARK: - Links
struct Links: Codable {
    let linksSelf: SelfClass

    enum CodingKeys: String, CodingKey {
        case linksSelf = "self"
    }
}

 To parse values from Alamofire responses: Alamofire.request(url).responseSelfClass { response in if let selfClass = response.result.value {... } }

// MARK: - SelfClass
struct SelfClass: Codable {
    let href: String
}

從 Alamofire 響應中解析值：

 Alamofire.request(url).responseValueInfo { response in if let valueInfo = response.result.value {... } }

// MARK: - ValueInfo
struct ValueInfo: Codable {
}

// MARK: - Helper functions for creating encoders and decoders

func newJSONDecoder() -> JSONDecoder {
    let decoder = JSONDecoder()
    if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {
        decoder.dateDecodingStrategy = .iso8601
    }
    return decoder
}

func newJSONEncoder() -> JSONEncoder {
    let encoder = JSONEncoder()
    if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {
        encoder.dateEncodingStrategy = .iso8601
    }
    return encoder
}

// MARK: - Alamofire response handlers

extension DataRequest {
    fileprivate func decodableResponseSerializer<T: Decodable>() -> DataResponseSerializer<T> {
        return DataResponseSerializer { _, response, data, error in
            guard error == nil else { return .failure(error!) }

            guard let data = data else {
                return .failure(AFError.responseSerializationFailed(reason: .inputDataNil))
            }

            return Result { try newJSONDecoder().decode(T.self, from: data) }
        }
    }

    @discardableResult
    fileprivate func responseDecodable<T: Decodable>(queue: DispatchQueue? = nil, completionHandler: @escaping (DataResponse<T>) -> Void) -> Self {
        return response(queue: queue, responseSerializer: decodableResponseSerializer(), completionHandler: completionHandler)
    }

    @discardableResult
    func responseWelcome(queue: DispatchQueue? = nil, completionHandler: @escaping (DataResponse<Welcome>) -> Void) -> Self {
        return responseDecodable(queue: queue, completionHandler: completionHandler)
    }
}

Answer 4

這是一個基本的 Alamofire 請求。 如果使用下面的結構解析json應該不會出錯。

    Alamofire.request(url, headers: headers).responseJSON { response in
        switch response.result {
        case .success(let value):
            let jsonData = value as! NSDictionary
            completionHandler(jsonData, nil)
            print("****** JSON \(jsonData)")
        case .failure(let error):
            completionHandler(nil, error)
        }

在這里，我將它放在您的代碼中。 您應該嘗試如下所示的標題。 您需要填寫適當的標題。

func asURLRequest() throws -> URLRequest {
    let url = try K.ProductionServer.baseURL.asURL()

    var urlRequest = URLRequest(url: url.appendingPathComponent(path))
    print(urlRequest)
    // HTTP Method
    urlRequest.httpMethod = method.rawValue

    let authToken = UserDefaults.standard.string(forKey: "authToken")
    let bearerToken: String = "Bearer " + (authToken ?? "")
    print("baearer token::\(bearerToken)")

    // Common Headers
    //urlRequest.setValue(ContentType.json.rawValue, forHTTPHeaderField: 
    //HTTPHeaderField.acceptType.rawValue)
    //urlRequest.setValue(ContentType.json.rawValue, forHTTPHeaderField: 
    //HTTPHeaderField.contentType.rawValue)
    //urlRequest.setValue(bearerToken, forHTTPHeaderField: 
    //HTTPHeaderField.authentication.rawValue)

    let headers: HTTPHeaders = [
        "Content-Type": "application/json",
        "Authorization": "Basic " + currentToken
    ]

    Alamofire.request(url, headers: headers).responseJSON { response in
        switch response.result {
        case .success(let value):
            let jsonData = value as! NSDictionary
            completionHandler(jsonData, nil)
            print("****** JSON \(jsonData)")
        case .failure(let error):
            completionHandler(nil, error)
        }

//return urlRequest
}

希望這可以幫助