iOS - 超时失败的同步请求

iOS - Synchronous Request with Timeout failing

我有这样的代码:

let urlPath: String = "https://github.com/zemirco/sf-city-lots-json/raw/master/citylots.json"
var url: NSURL = NSURL(string: urlPath)!
var request1: NSURLRequest = NSURLRequest(URL: url, 
                                  cachePolicy: NSURLRequestCachePolicy.ReturnCacheDataElseLoad, 
                              timeoutInterval: 1)

var response:NSURLResponse?;
var error:NSError?;

/*** the follow line is giving the error ***/
var data:NSData =  NSURLConnection.sendSynchronousRequest(
                                                  request1, 
                               returningResponse: &response, 
                                           error: &error)!

if( error != nil) {
    println ("ERROR")
} else {
    println(response)
    self.config = (NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary)

}
println("Done with Synchronous Request")

如果请求花费的时间太长,NSURLConnection.sendSynchronousRequest(...) 调用有一个 fatal error: unexpectedly found nil while unwrapping an Optional value。我不确定发生了什么。当我查看调试 window 时,唯一的 nil 变量是 response。此代码看起来与我在网上看到的示例非常相似。

如果请求在规定时间内完成,则不会发生致命错误。

我希望能够捕获超时错误。有人知道代码有什么问题吗?

你在这一行的错误位置有感叹号,

var data:NSData =  NSURLConnection.sendSynchronousRequest(request1, returningResponse: &response, error: &error)!

应该是,

var data:NSData! =  NSURLConnection.sendSynchronousRequest(request1, returningResponse: &response, error: &error)