ios - 进行 JSON 序列化时出错 ErrorDomain Code=3840

Question

我正在尝试删除 TableView 中的帖子，但在进行 JSON 序列化时出现错误，在这一行

let json = try JSONSerialization.jsonObject(with: data!, options: []) as? [String: AnyObject]

如果是通过浏览器访问url，成功删除数据库中的数据，如果是从浏览器访问，也是这样返回json响应

{"message":"successfully deleted","result":1,"status":"Image has been deleted from drive"}

但我得到一个错误，提示 json 文本不是以数组或对象开头(代码 =3840)，但正如您在上面看到的，它是一个 json 字典

Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}

这是我使用的完整代码。这里出了什么问题？谢谢

func deletePost(_ indexPath: IndexPath) {

    let tweet = tweetsArray[indexPath.row]
    let uuid = tweet["uuid"] as! String
    let imagePath = tweet["imagePath"] as! String

    let url = URL(string: "http://localhost/Twitter/post.php")
    var request = URLRequest(url: url!)
    request.httpMethod = "POST"
    let body = "uuid=\(uuid)&path=\(imagePath)"
    request.httpBody = body.data(using: String.Encoding.utf8)

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

        if error == nil {

            do {

                let json = try JSONSerialization.jsonObject(with: data!, options: []) as? [String: AnyObject]

                guard let parsedJSON = json else {
                    print("error while parsing JSON")
                    return
                }

                let jsonMessage = parsedJSON["message"]
                if jsonMessage != nil {
                    // hilangkan data di array
                    self.tweetsArray.remove(at: indexPath.row)
                    self.imagesArray.remove(at: indexPath.row)

                    // hilangkan rownya pada table view
                    self.tableView.deleteRows(at: [indexPath], with: .automatic)
                    self.tableView.reloadData()
                }
            }
            catch {

                // get main queue to communicate back to user
                DispatchQueue.main.async(execute: {
                    let message = "\(error)"
                    self.showAlert(alertTitle: "sorry", alertMessage: message, actionTitle: "OK")
                })
                return
            }
        }
        else {

            // get main queue to communicate back to user
            DispatchQueue.main.async(execute: {
                let message = "\(error!.localizedDescription)"
                self.showAlert(alertTitle: "sorry", alertMessage: message, actionTitle: "OK")
            })
            return
        }
    }
    task.resume()
}

Answer 1

您可以尝试打印出您的服务器响应。请像这样更改 catch block 中的代码。并识别服务器端是否有错误。

您的服务器数据是正确的 json 格式然后打印出您的服务器数据并检查服务器数据是否有效。

URLSession.shared.dataTask(with: url) { (data, response, error) in

        if let jsonData = data {
            do {
                let parsedData = try JSONSerialization.jsonObject(with: jsonData, options: .mutableLeaves) as! [String: AnyObject]
                if let area = parsedData["AREA"] as? [[String: AnyObject]] {
                    for a in area {
                        print(a["area_name"])
                        print(a["price"])
                    }
                }
            }
            catch let err{
                print("\n\n===========Error===========")
                print("Error Code: \(error!._code)")
                print("Error Messsage: \(error!.localizedDescription)")
                if let data = data, let str = String(data: data, encoding: String.Encoding.utf8){
                    print("Server Error: " + str)
                }
                debugPrint(error)
                print("===========================\n\n")

                debugPrint(err)
            }
        }
        else {
            debugPrint(error as Any)
        }

    }.resume()