快速下载和解析 json

I'm trying to get the JSON from a website and parse it before putting it inside of an iOS view.

Here's my code;

func startConnection(){
        let urlPath: String = "http://binaenaleyh.net/dusor/"
        var url: NSURL = NSURL(string: urlPath)
        var request: NSURLRequest = NSURLRequest(URL: url)
        var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)
        connection.start()
    }

    func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
        self.data.appendData(data)
    }

    func buttonAction(sender: UIButton!){
        startConnection()
    }

    func connectionDidFinishLoading(connection: NSURLConnection!) {
        var err: NSError
        // throwing an error on the line below (can't figure out where the error message is)
        var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
    }

And this is the link for the JSON;

http://binaenaleyh.net/dusor/

我在这里做错了什么？