How to make HTTP Post request with JSON body in Swift

Try this,

// prepare json datalet json: [String: Any] = ["title": "ABC",                           "dict": ["1":"First", "2":"Second"]]let jsonData = try? JSONSerialization.data(withJSONObject: json)// create post requestlet url = URL(string: "http://httpbin.org/post")!var request = URLRequest(url: url)request.httpMethod = "POST"// insert json data to the requestrequest.httpBody = jsonDatalet task = URLSession.shared.dataTask(with: request) { data, response, error in    guard let data = data, error == nil else {        print(error?.localizedDescription ?? "No data")        return    }    let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])    if let responseJSON = responseJSON as? [String: Any] {        print(responseJSON)    }}task.resume()

or try a convenient way Alamofire

Swift 4 and 5

HTTP POST request using URLSession API in Swift 4

func postRequest(username: String, password: String, completion: @escaping ([String: Any]?, Error?) -> Void) {    //declare parameter as a dictionary which contains string as key and value combination.    let parameters = ["name": username, "password": password]    //create the url with NSURL    let url = URL(string: "https://www.myserver.com/api/login")!    //create the session object    let session = URLSession.shared    //now create the Request object using the url object    var request = URLRequest(url: url)    request.httpMethod = "POST" //set http method as POST    do {        request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted) // pass dictionary to data object and set it as request body    } catch let error {        print(error.localizedDescription)        completion(nil, error)    }    //HTTP Headers    request.addValue("application/json", forHTTPHeaderField: "Content-Type")    request.addValue("application/json", forHTTPHeaderField: "Accept")    //create dataTask using the session object to send data to the server    let task = session.dataTask(with: request, completionHandler: { data, response, error in        guard error == nil else {            completion(nil, error)            return        }        guard let data = data else {            completion(nil, NSError(domain: "dataNilError", code: -100001, userInfo: nil))            return        }        do {            //create json object from data            guard let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] else {                completion(nil, NSError(domain: "invalidJSONTypeError", code: -100009, userInfo: nil))                return            }            print(json)            completion(json, nil)        } catch let error {            print(error.localizedDescription)            completion(nil, error)        }    })    task.resume()}@objc func submitAction(_ sender: UIButton) {    //call postRequest with username and password parameters    postRequest(username: "username", password: "password") { (result, error) in    if let result = result {        print("success: \(result)")    } else if let error = error {        print("error: \(error.localizedDescription)")    }}

Using Alamofire:

let parameters = ["name": "username", "password": "password123"]Alamofire.request("https://www.myserver.com/api/login", method: .post, parameters: parameters, encoding: URLEncoding.httpBody)

HTTP Post in Swift capturing the errors

let json = [ Activity.KEY_IDSUBJECT : activity.idSubject, Activity.KEY_RECORDMODE : "3", Activity.KEY_LOCATION_LONGITUDE : "0",Activity.KEY_LOCATION_LATITUDE : "0", Activity.KEY_CHECKIN : String(activity.dateCheckIn), Activity.KEY_CHECKOUT : String(activity.dateCheckOut) ]do {    let jsonData = try NSJSONSerialization.dataWithJSONObject(json, options: .PrettyPrinted)    // create post request    let url = NSURL(string: "https://...appspot.com/_ah/api/activityendpoint/v1/activity")!    let request = NSMutableURLRequest(URL: url)    request.HTTPMethod = "POST"    // insert json data to the request    request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")    request.HTTPBody = jsonData    let task = NSURLSession.sharedSession().dataTaskWithRequest(request){ data, response, error in        if error != nil{            print("Error -> \(error)")            return        }        do {            let result = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String:AnyObject]            print("Result -> \(result)")        } catch {            print("Error -> \(error)")        }    }    task.resume()    return task} catch {    print(error)}