使用URLSession + Swift

只是补充cezar的答案，如果你想使用苹果的URLSession类进行web请求，有多种方法来完成任务

简单的GET请求与URL 简单的GET请求与URL和参数 简单的GET请求与错误处理的URL 简单的POST请求与URL，参数与错误处理

1. 简单的GET请求与URL

func simpleGetUrlRequest()
    {
        let url = URL(string: "https://httpbin.org/get")!

        let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
            guard let data = data else { return }
            print("The response is : ",String(data: data, encoding: .utf8)!)
            //print(NSString(data: data, encoding: String.Encoding.utf8.rawValue) as Any)
        }
        task.resume()
    }

注意:请确保您必须在pList中为http请求添加“NSAppTransportSecurity”键

<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>

2. 简单的GET请求与URL和参数

func simpleGetUrlWithParamRequest()
    {
        let url = URL(string: "https://www.google.com/search?q=peace")!
        
        let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Server error!")
                return
            }
            print("The Response is : ",response)
        }
        task.resume()
    }

3.简单的GET请求与错误处理的URL

func simpleGetUrlRequestWithErrorHandling()
    {
        let session = URLSession.shared
        let url = URL(string: "https://httpbin.org/get")!
        
        let task = session.dataTask(with: url) { data, response, error in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Server error!")
                return
            }
            
            guard let mime = response.mimeType, mime == "application/json" else {
                print("Wrong MIME type!")
                return
            }
            
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: [])
                print("The Response is : ",json)
            } catch {
                print("JSON error: \(error.localizedDescription)")
            }
            
        }
        task.resume()
    }

4. 简单的POST请求与URL，参数与错误处理。

func simplePostRequestWithParamsAndErrorHandling(){
        let configuration = URLSessionConfiguration.default
        configuration.timeoutIntervalForRequest = 30
        configuration.timeoutIntervalForResource = 30
        let session = URLSession(configuration: configuration)
        
        let url = URL(string: "https://httpbin.org/post")!
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")
        
        let parameters = ["username": "foo", "password": "123456"]
        
        do {
            request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
        } catch let error {
            print(error.localizedDescription)
        }
        
        let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Oops!! there is server error!")
                return
            }
            
            guard let mime = response.mimeType, mime == "application/json" else {
                print("response is not json")
                return
            }
            
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: [])
                print("The Response is : ",json)
            } catch {
                print("JSON error: \(error.localizedDescription)")
            }
            
        })
        
        task.resume()
    }

谢谢你的建议!!

基本的Swift 3+解决方案

guard let url = URL(string: "http://www.stackoverflow.com") else { return }

let task = URLSession.shared.dataTask(with: url) { data, response, error in

  guard let data = data, error == nil else { return }

  print(NSString(data: data, encoding: String.Encoding.utf8.rawValue))
}

task.resume()

答:吻

URLSession.shared.dataTask(with: URL(string: "https://google.com")!) {(data, response, error) in
    print(String(data: data!, encoding: .utf8))
}.resume()

细节

Xcode 9.2, Swift 4 Xcode 10.2.1 (10E1001)

Info.plist

NSApp传输安全

添加到info plist:

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>

Alamofire样本

Alamofire

import Alamofire

class AlamofireDataManager {
    fileprivate let queue: DispatchQueue
    init(queue: DispatchQueue) { self.queue = queue }

    private func createError(message: String, code: Int) -> Error {
        return NSError(domain: "dataManager", code: code, userInfo: ["message": message ])
    }

    private func make(session: URLSession = URLSession.shared, request: URLRequest, closure: ((Result<[String: Any]>) -> Void)?) {
        Alamofire.request(request).responseJSON { response in
            let complete: (Result<[String: Any]>) ->() = { result in DispatchQueue.main.async { closure?(result) } }
            switch response.result {
                case .success(let value): complete(.success(value as! [String: Any]))
                case .failure(let error): complete(.failure(error))
            }
        }
    }

    func searchRequest(term: String, closure: ((Result<[String: Any]>) -> Void)?) {
        guard let url = URL(string: "https://itunes.apple.com/search?term=\(term.replacingOccurrences(of: " ", with: "+"))") else { return }
        let request = URLRequest(url: url)
        make(request: request) { response in closure?(response) }
    }
}

Alamofire样品的使用

private lazy var alamofireDataManager = AlamofireDataManager(queue: DispatchQueue(label: "DataManager.queue", qos: .utility))
//.........

alamofireDataManager.searchRequest(term: "jack johnson") { result in
      print(result.value ?? "no data")
      print(result.error ?? "no error")
}

URLSession样本

import Foundation

class DataManager {

    fileprivate let queue: DispatchQueue
        init(queue: DispatchQueue) { self.queue = queue }

    private func createError(message: String, code: Int) -> Error {
        return NSError(domain: "dataManager", code: code, userInfo: ["message": message ])
    }

    private func make(session: URLSession = URLSession.shared, request: URLRequest, closure: ((_ json: [String: Any]?, _ error: Error?)->Void)?) {
        let task = session.dataTask(with: request) { [weak self] data, response, error in
            self?.queue.async {
                let complete: (_ json: [String: Any]?, _ error: Error?) ->() = { json, error in DispatchQueue.main.async { closure?(json, error) } }

                guard let self = self, error == nil else { complete(nil, error); return }
                guard let data = data else { complete(nil, self.createError(message: "No data", code: 999)); return }

                do {
                    if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
                        complete(json, nil)
                    }
                } catch let error { complete(nil, error); return }
            }
        }

        task.resume()
    }

    func searchRequest(term: String, closure: ((_ json: [String: Any]?, _ error: Error?)->Void)?) {
        let url = URL(string: "https://itunes.apple.com/search?term=\(term.replacingOccurrences(of: " ", with: "+"))")
        let request = URLRequest(url: url!)
        make(request: request) { json, error in closure?(json, error) }
    }
}

URLSession示例的使用

private lazy var dataManager = DataManager(queue: DispatchQueue(label: "DataManager.queue", qos: .utility))
// .......
dataManager.searchRequest(term: "jack johnson") { json, error  in
      print(error ?? "nil")
      print(json ?? "nil")
      print("Update views")
}

结果

下面是一个非常简单的Swift 4在操场上的例子:

import UIKit
// run asynchronously in a playground
import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true

// create a url
let url = URL(string: "http://www.stackoverflow.com")

// create a data task
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
    if error != nil {
        print("there's a problem")
    }
    print(String(data: data!, encoding: String.Encoding.utf8) ?? "")
}

//running the task w/ resume
task.resume()

在Swift 4.1和Xcode 9.4.1中。

JSON POST方法示例。要检查互联网连接，从https://developer.apple.com/library/archive/samplecode/Reachability/Introduction/Intro.html#//apple_ref/doc/uid/DTS40007324-Intro-DontLinkElementID_2添加Reachability.h & .m文件

func yourFunctionName {
    //Check internet connection
    let networkReachability = Reachability.forInternetConnection()
    let networkStatus:Int = (networkReachability?.currentReachabilityStatus())!.rawValue
    print(networkStatus)
    if networkStatus == NotReachable.rawValue {
        let msg = SharedClass.sharedInstance.noNetMsg//Message
        //Call alert from shared class
        SharedClass.sharedInstance.alert(view: self, title: "", message: msg)
    } else {
        //Call spinner from shared class
        SharedClass.sharedInstance.activityIndicator(view: self.view)//Play spinner

        let parameters = "Your parameters here"
        var request = URLRequest(url: URL(string: url)!)

        request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        request.httpMethod = "POST"

        print("URL : \(request)")

        request.httpBody = parameters.data(using: .utf8)

        let task = URLSession.shared.dataTask(with: request) { data, response, error in guard let data = data, error == nil else { // check for fundamental networking error
            //Stop spinner
            SharedClass.sharedInstance.stopActivityIndicator() //Stop spinner
            //Print error in alert
            SharedClass.sharedInstance.alert(view: self, title: "", message: "\(String(describing: error!.localizedDescription))")
            return
            }

            SharedClass.sharedInstance.stopActivityIndicator() //Stop spinner

            if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 { // check for http errors
                print("statusCode should be 200, but is \(httpStatus.statusCode)")
                print("response = \(String(describing: response))")
            }

            do {
                let response = try JSONSerialization.jsonObject(with: data, options: []) as? [String: AnyObject]
                print(response!)
                //Your code here                    
            } catch let error as NSError {
                print(error)
            }
        }

        task.resume()

    }

}

如果你有兴趣在SharedClass中使用这个函数

//My shared class
import UIKit
class SharedClass: NSObject {

static let sharedInstance = SharedClass()

func postRequestFunction(apiName: String , parameters: String, onCompletion: @escaping (_ success: Bool, _ error: Error?, _ result: [String: Any]?)->()) {

    var URL =  "your URL here/index.php/***?"

    URL = URL.replacingOccurrences(of: "***", with: apiName)

    var request = URLRequest(url: URL(string: URL)!)
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.httpMethod = "POST"
    print("shared URL : \(request)")
    request.httpBody = parameters.data(using: .utf8)

    var returnRes:[String:Any] = [:]
    let task = URLSession.shared.dataTask(with: request) { data, response, error in

        if let error = error {
            onCompletion(false, error, nil)
        } else {
            guard let data = data else {
                onCompletion(false, error, nil)
                return
            }

            if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode == 200 {
                do {
                   returnRes = try JSONSerialization.jsonObject(with: data, options: []) as! [String : Any]
                    onCompletion(true, nil, returnRes)

                } catch let error as NSError {
                   onCompletion(false, error, nil)
                }
            } else {
                onCompletion(false, error, nil)
            }
        }
    }
    task.resume()
}


private override init() {

}

最后像这样调用这个函数....

SharedClass.sharedInstance.postRequestFunction(apiName: "Your API name", parameters: parameters) { (success, error, result) in
    print(result!)
    if success {
        //Your code here
    } else {
        print(error?.localizedDescription ?? "")
    }
}