过Swift中的NSURLSession以某种方式执行同步HTT

过Swift中的NSURLSession以某种方式执行同步HTT

本文介绍了我可以通过Swift中的NSURLSession以某种方式执行同步HTTP请求的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我可以通过Swift中的 NSURLSession 以某种方式执行同步HTTP请求吗?

Can I somehow do a synchronous HTTP request via NSURLSession in Swift?

我可以执行异步请求通过以下代码:

I can do an asynchronous request via the following code:

if let url = NSURL(string: "https://2ch.hk/b/threads.json") {
            let task = NSURLSession.sharedSession().dataTaskWithURL(url) {
                (data, response, error) in

                var jsonError: NSError?
                let jsonDict = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &jsonError) as [String: AnyObject]
                if jsonError != nil {
                    return
                }

                // ...
            }
            task.resume()
        }

但同步请求呢?

提前致谢。

推荐答案

您可以使用此NSURLSession扩展来添加同步方法:

You can use this NSURLSession extension to add a synchronous method:

extension NSURLSession {
    func synchronousDataTaskWithURL(url: NSURL) -> (NSData?, NSURLResponse?, NSError?) {
        var data: NSData?, response: NSURLResponse?, error: NSError?

        let semaphore = dispatch_semaphore_create(0)

        dataTaskWithURL(url) {
            data = $0; response = $1; error = $2
            dispatch_semaphore_signal(semaphore)
        }.resume()

        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER)

        return (data, response, error)
    }
}

Swift 3的更新:

extension URLSession {
    func synchronousDataTask(with url: URL) -> (Data?, URLResponse?, Error?) {
        var data: Data?
        var response: URLResponse?
        var error: Error?

        let semaphore = DispatchSemaphore(value: 0)

        let dataTask = self.dataTask(with: url) {
            data = $0
            response = $1
            error = $2

            semaphore.signal()
        }
        dataTask.resume()

        _ = semaphore.wait(timeout: .distantFuture)

        return (data, response, error)
    }
}

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09-05 00:56