ios - 为什么我的 JSON URL 不输出 JSON 数据？

Question

我已经检查了 URL 并且它有效，但是当我尝试输出 readableJSON 时，它是空的？!

这是我的输出:

Not empty now
2016-02-20 10:19:29.162 ThisLondon[55922:4080604] the URL: [

]
2016-02-20 10:19:29.162 ThisLondon[55922:4080604] 0

这是我的代码:

selectedTube = "Circle"
let url = NSURL(string: "https://api.tfl.gov.uk/Line/\(selectedTube)/Arrivals?app_id=6573044a&app_key=7a97df35339dc68625384077a5e07304")
let jsonData = NSData(contentsOfURL: url!)
let readableJSON = JSON(data: jsonData!, options: NSJSONReadingOptions.MutableContainers, error: nil)

NSLog("the URL: \(readableJSON)")

Answer 1

尝试使用这个:

    let selectedTube = "circle"
        let headers = ["cache-control": "no-cache",]

let request = NSMutableURLRequest(URL: NSURL(string: "https://api.tfl.gov.uk/Line/\(selectedTube)/Arrivals?app_id=6573044a&app_key=7a97df35339dc68625384077a5e07304")!,
                                                cachePolicy: .UseProtocolCachePolicy,
                                            timeoutInterval: 10.0)
        request.HTTPMethod = "GET"
        request.allHTTPHeaderFields = headers

        let session = NSURLSession.sharedSession()
        let dataTask = session.dataTaskWithRequest(request, completionHandler: { (data, response, error) -> Void in
          if (error != nil) {
            print(error)
          } else {
            let httpResponse = response as? NSHTTPURLResponse
            print(httpResponse)
          }
        })

        dataTask.resume()