import Cocoa class uploadToServer: NSObject { func upload() { let config = URLSessionConfiguration.default let url = URL(string: "http://localhost:8042/instances") let request = NSMutableURLRequest(url: url!) request.httpMethod = "POST" request.setValue("Keep-Alive", forHTTPHeaderField: "Connection") let folder = Bundle.main.path(forResource: "dicom", ofType: "")! for i in 1...10 { let session = URLSession(configuration: config) let data = NSData(contentsOfFile: folder + "/" + String(i) + ".dcm") let task = session.uploadTask(with: request as URLRequest, from: data as Data?){ data, response, error -> Void in if error != nil { print("error = \(error!)") } else { print(i) } // end if } // end task task.resume() } // end for } // end func } // end class