如何在Swift中创建NSURLSession POST请求

Question

嗨,我是Swift的初学者,我正在尝试使NSURLSession"发布"请求发送一些参数,如下面的代码

根据我的下面的代码响应不是来自服务器可以有人帮助我

BackGroundClass: -

 import UIKit

protocol sampleProtocal{

    func getResponse(result:NSDictionary)
    func getErrorResponse(error:NSString)
}

class BackGroundClass: NSObject {

    var delegate:sampleProtocal?

    func callPostService(url:String,parameters:NSDictionary){


        print("url is===>\(url)")

        let request = NSMutableURLRequest(URL: NSURL(string:url)!)

        let session = NSURLSession.sharedSession()
        request.HTTPMethod = "POST"

        //Note : Add the corresponding "Content-Type" and "Accept" header. In this example I had used the application/json.
        request.addValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")

        request.HTTPBody = try! NSJSONSerialization.dataWithJSONObject(parameters, options: [])

        let task = session.dataTaskWithRequest(request) { data, response, error in
            guard data != nil else {
                print("no data found: \(error)")
                return
            }

            do {
                if let json = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? NSDictionary {
                    print("Response: \(json)")
                    self.mainResponse(json)
                } else {
                    let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)// No error thrown, but not NSDictionary
                    print("Error could not parse JSON: \(jsonStr)")
                    self.eroorResponse(jsonStr!)
                }
            } catch let parseError {
                print(parseError)// Log the error thrown by `JSONObjectWithData`
                let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)
                print("Error could not parse JSON: '\(jsonStr)'")
                self.eroorResponse(jsonStr!)
            }
        }

        task.resume()
    }

    func mainResponse(result:NSDictionary){
        delegate?.getResponse(result)
    }

    func eroorResponse(result:NSString){
        delegate?.getErrorResponse(result)
    }
}

视图控制器: -

import UIKit

class ViewController: UIViewController,sampleProtocal {

    override func viewDidLoad() {
        super.viewDidLoad()

        let delegate = BackGroundClass();
        delegate.self;

        let params = ["scancode":"KK03799-008", "UserName":"admin"] as Dictionary<String, String>

        let backGround=BackGroundClass();
        backGround.callPostService("url", parameters: params)
    }

    func getResponse(result: NSDictionary) {
        print("Final response is\(result)");
    }

    func getErrorResponse(error: NSString) {
        print("Final Eroor code is\(error)")
    }
}

Answer 1

Swift 4帖子示例 -

func postAction(_ sender: Any) {
        let Url = String(format: "your url")
        guard let serviceUrl = URL(string: Url) else { return }
        let parameterDictionary = ["username" : "Test", "password" : "123456"]
        var request = URLRequest(url: serviceUrl)
        request.httpMethod = "POST"
        request.setValue("Application/json", forHTTPHeaderField: "Content-Type")
        guard let httpBody = try? JSONSerialization.data(withJSONObject: parameterDictionary, options: []) else {
            return
        }
        request.httpBody = httpBody

        let session = URLSession.shared
        session.dataTask(with: request) { (data, response, error) in
            if let response = response {
                print(response)
            }
            if let data = data {
                do {
                    let json = try JSONSerialization.jsonObject(with: data, options: [])
                    print(json)
                } catch {
                    print(error)
                }
            }
            }.resume()
    }

Answer 2

尝试运行此函数并打印响应,它在Swift 4.0中.

在这里,我准备了可编码的结构:

struct LoginData: Codable {
    var code: Int?
    var message: String?
    var status: String?
    var token: String?
    var data: DataSet?
}
struct DataSet: Codable {
    var email : String?
    var contactNo : String?
    var firstName : String?
    var lastName: String?
    var dob : String?
    var gender : String?
    var address: String?
    var city : String?
    var state : String?
    var country : String?
    var zip : String?
    var username: String?
}

如果您正确打印了响应,则将其传递给viewController.

func loginWS(parameters:[String:String], completionHandler: @escaping (Any?) -> Swift.Void) {

    guard let gitUrl = URL(string: BASE_URL+ACTION_URL) else { return }
    print(gitUrl)

    let request = NSMutableURLRequest(url: gitUrl)
    //  uncomment this and add auth token, if your project needs.
    //  let config = URLSessionConfiguration.default
    //  let authString = "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoxMywiUGFzc3dvcmQiOiIkMmEkMTAkYVhpVm9wU3JSLjBPYmdMMUk2RU5zdU9LQzlFR0ZqNzEzay5ta1pDcENpMTI3MG1VLzR3SUsiLCJpYXQiOjE1MTczOTc5MjV9.JaSh3FvpAxFxbq8z_aZ_4OhrWO-ytBQNu6A-Fw4pZBY"
    //  config.httpAdditionalHeaders = ["Authorization" : authString]

    let session = URLSession.shared
    request.httpMethod = "POST"
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    request.httpBody = try! JSONSerialization.data(withJSONObject: parameters, options: [])

    let task = session.dataTask(with: request as URLRequest) { data, response, error in

        guard let data = data else { return }
        do {
        //  let decoder = JSONDecoder()
        //  here replace LoginData with your codable structure.
            let gitData = try JSONDecoder().decode(LoginData.self, from: data)
            print("response data:", gitData) 
            completionHandler(gitData)
        } catch let err {
            print("Err", err)
        }
        }.resume()
}

Answer 3

这是一个与Swift 4和Swift 5兼容的完整解决方案示例。

Endpoint 创建网址

struct Endpoint {
    let path: String
    let queryItems: [URLQueryItem]?
}

extension Endpoint {
    var url: URL? {
        var components = URLComponents()
        components.scheme = "https"
        components.host = "YOUR_HOST"
        components.path = path
        components.queryItems = queryItems
        return components.url
    }
}

User 请求体的对象模型

struct User: Encodable {
    let name: String
    let surname: String
    let age: Int

    // this is to customise init 
    init(name: String,
         surname: String,
         age: Int) {
        self.name = name
        self.surname = surname
        self.age = age
    }

    enum CodingKeys: String, CodingKey {
        case name, surname, age
    }
}

UserResponse http 响应模型来自 API

struct UserResponse: Decodable {
    let message: String
    let userId: String?

    enum CodingKeys: String, CodingKey {
        case message, userId = "user_id" // API returns userId as "user_id"
    }
}

APIClient 为我们的 api 发出 http 请求

protocol APIClientProtocol: Any {
    func sendUser(_ user: User, completionBlock: @escaping (_ userResponse: UserResponse?, _ error: APIClient.Error?) -> Void)
}

class APIClient: APIClientProtocol {

    fileprivate let defaultSession: URLSession = {
        let configuration = URLSessionConfiguration.default
        configuration.timeoutIntervalForRequest = 10.0
        configuration.timeoutIntervalForResource = 10.0
        return URLSession(configuration: configuration, delegate: nil, delegateQueue: nil)
    }()

    public init() { }

    public func uploadUser(_ user: User, completionBlock: @escaping (UserResponse?, APIClient.Error?) -> Void) {
        guard let url = Endpoint(path: "/user/upload", queryItems: nil).url else {
            completionBlock(nil, .brokenURL)
            return
        }
        var urlRequest = URLRequest(url: url)
        urlRequest.httpMethod = "POST"
        urlRequest.addValue("application/json", forHTTPHeaderField: "Content-Type")
        urlRequest.addValue("application/json", forHTTPHeaderField: "Accept")
        do {
            let jsonData = try JSONEncoder().encode(user)
            urlRequest.httpBody = jsonData
        } catch {
            completionBlock(nil, .serialization(error.localizedDescription))
            return
        }
        let task = defaultSession.dataTask(with: urlRequest) { data, urlResponse, error in
            if let error = error {
                completionBlock(nil, .http(error.localizedDescription))
                return
            }
            guard let httpResponse = urlResponse as? HTTPURLResponse else {
                return
            }
            if httpResponse.statusCode == 200 {
                guard let data = data else {
                    return
                }
                do {
                    let userResponse = try JSONDecoder().decode(UserResponse.self, from: data)
                    completionBlock(userResponse, nil)
                } catch let error {
                    completionBlock(nil, .serialization(error.localizedDescription))
                }
            } else {
                completionBlock(nil, .http("Status failed!"))
            }
        }
        task.resume()
    }

}

extension APIClient {

    enum Error: Swift.Error, Equatable {
        case brokenURL
        case serialization(String)
        case http(String)
    }

}

Answer 4

缺少 HTTP 正文。示例 - 将字符串参数设置为正文

let paramString = String(format:"param1=%@&param2=%@",param1,param2)
request.httpBody = paramString.data(using: String.Encoding.utf8)

在这里尝试一下

request.httpBody = NSJSONSerialization.dataWithJSONObject(params, options: nil, error: &err)