func getStsToken()

in OSSSwiftDemo/OSSSwiftDemo/Classes/OSSRootViewController.swift [171:209]
28 lines of code
2 McCabe index (conditional complexity)

    func getStsToken() -> Void {
        let tcs = OSSTaskCompletionSource<AnyObject>()
        let federationProvider: OSSFederationCredentialProvider = OSSFederationCredentialProvider(federationTokenGetter: {() ->OSSFederationToken? in
            let url: URL = URL(string: OSS_STSTOKEN_URL)!
            let config: URLSessionConfiguration = URLSessionConfiguration.default;
            let session: URLSession = URLSession(configuration: config, delegate: self as URLSessionDelegate, delegateQueue: nil);
            
            let task = session.dataTask(with: url, completionHandler: { (data, response, error) -> Void in
                
                //Convert Data to Jsons
                tcs.setResult(data as AnyObject)
            })
            task.resume()
            tcs.task.waitUntilFinished()
            
            let json = try? JSONSerialization.jsonObject(with: tcs.task.result as! Data,
                                                         options:.allowFragments) as! [String: Any]
            print("Json Object:", json as Any)
            
            //verify json
            let accessKeyId = json?["AccessKeyId"]
            let accessKeySecret = json?["AccessKeySecret"]
            
            self.ossAlert(title: "notice", message: json?.description)
            
            
            let token = OSSFederationToken()
            token.tAccessKey = accessKeyId as! String
            token.tSecretKey = accessKeySecret as! String
            
            return token
        })
        
        do {
            try federationProvider.getToken()
        } catch{
            print("get Error")
        }
    }