Swift 3中的HTTP请求

>默认情况下,您的应用无法连接到不安全(即HTTP)网站.这是一项名为App Transport Security的功能.您需要在应用的Info.plist文件中进行异常才能连接到HTTP站点.
>这：dataTask(urlwith：！as URL).你想用感叹号解开什么(！)？什么是变量名称？@H_301_2@

很多类名在Swift 2和3之间发生了变化,因此您找到的答案可能不适用.以下示例连接到httpbin.org以获取您的IP地址：@H_301_2@

import PlaygroundSupport
import Foundation

let url = URL(string: "https://httpbin.org/ip")

let task = URLSession.shared.dataTask(with: url!) { data,response,error in
    guard error == nil else {
        print(error!)
        return
    }
    guard let data = data else {
        print("Data is empty")
        return
    }

    let json = try! JSONSerialization.jsonObject(with: data,options: [])
    print(json)
}

task.resume()
PlaygroundPage.current.needsIndefiniteExecution = true