下面是在Linux上使用Swift进行HTTP请求的从头到尾的说明。

首先创建一个SwiftPM包

mkdir swift-http && cd swift-http && swift package init --type executable

然后替换。/Sources/swift-http/main.swift 代码如下:

import Foundation
import FoundationNetworking

let sema = DispatchSemaphore(value: 0)

URLSession.shared.dataTask(with: URL(string: "http://numbersapi.com/42")!) {(data, response, error) in
    print(String(data: data!, encoding: .utf8) ?? String(describing: error))
    sema.signal()
}.resume()

sema.wait()

然后运行代码

swift run

输出的例子:

[6/6] Build complete!
42 is the answer to the Ultimate Question of Life, the Universe, and Everything.

注意:使用DispatchSemaphore是为了使程序在得到响应之前不会退出。

你也可以这样做:

import Foundation
import FoundationNetworking

var done = false

URLSession.shared.dataTask(with: URL(string: "http://numbersapi.com/42")!) {(data, response, error) in
    print(String(data: data!, encoding: .utf8) ?? String(describing: error))
    done = true
}.resume()

while !done { Thread.sleep(forTimeInterval: 1) }

//这是一个对我有用的例子

//发送请求到服务器的Swift函数

func insertRecords()
{



    let usrID = txtID.text
    let checkin = lblInOut.text
    let comment = txtComment.text



    // The address of the web service
    let urlString = "http://your_url/checkInOut_post.php"

    // These are the keys that your are sending as part of the post request
    let keyValues = "id=\(usrID)&inout=\(checkin)&comment=\(comment)"




    // 1 - Create the session by getting the configuration and then
    //     creating the session

    let config = NSURLSessionConfiguration.defaultSessionConfiguration()
    let session = NSURLSession(configuration: config, delegate: nil, delegateQueue: nil)


    // 2 - Create the URL Object

    if let url = NSURL(string: urlString){


        // 3 - Create the Request Object

        var request  = NSMutableURLRequest(URL: url)
        request.HTTPMethod = "POST"

        // set the key values
        request.HTTPBody = keyValues.dataUsingEncoding(NSUTF8StringEncoding);


        // 4 - execute the request

        let taskData = session.dataTaskWithRequest(request, completionHandler: {

            (data:NSData!, response:NSURLResponse!, error:NSError!) -> Void in

            println("\(data)")

            // 5 - Do something with the Data back

            if (data != nil) {

                // we got some data back
                println("\(data)")

                let result = NSString(data: data , encoding: NSUTF8StringEncoding)
                println("\(result)")

                if result == "OK" {

                    let a = UIAlertView(title: "OK", message: "Attendece has been recorded", delegate: nil, cancelButtonTitle: "OK")

                    println("\(result)")

                    dispatch_async(dispatch_get_main_queue()) {


                    a.show()


                    }


                } else {
                  // display error and do something else

                }


            } else

            {   // we got an error
                println("Error getting stores :\(error.localizedDescription)")

            }


        })

        taskData.resume()



    }


}

PHP代码来获取键值

$empID = $_POST['id'];

$inOut = $_POST['inout'];

$comment = $_POST['comment'];

 var post:NSString = "api=myposts&userid=\(uid)&page_no=0&limit_no=10"

    NSLog("PostData: %@",post);

    var url1:NSURL = NSURL(string: url)!

    var postData:NSData = post.dataUsingEncoding(NSASCIIStringEncoding)!

    var postLength:NSString = String( postData.length )

    var request:NSMutableURLRequest = NSMutableURLRequest(URL: url1)
    request.HTTPMethod = "POST"
    request.HTTPBody = postData
    request.setValue(postLength, forHTTPHeaderField: "Content-Length")
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.setValue("application/json", forHTTPHeaderField: "Accept")

    var reponseError: NSError?
    var response: NSURLResponse?

    var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)

    if ( urlData != nil ) {
        let res = response as NSHTTPURLResponse!;

        NSLog("Response code: %ld", res.statusCode);

        if (res.statusCode >= 200 && res.statusCode < 300)
        {
            var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!

            NSLog("Response ==> %@", responseData);

            var error: NSError?

            let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &error) as NSDictionary

            let success:NSInteger = jsonData.valueForKey("error") as NSInteger

            //[jsonData[@"success"] integerValue];

            NSLog("Success: %ld", success);

            if(success == 0)
            {
                NSLog("Login SUCCESS");

                self.dataArr = jsonData.valueForKey("data") as NSMutableArray
                self.table.reloadData()

            } else {

                NSLog("Login failed1");
                ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")
            }

        } else {

            NSLog("Login failed2");
            ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")

        }
    } else {

        NSLog("Login failed3");
        ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")
}

它一定会对你有帮助

我调用json登录按钮点击

@IBAction func loginClicked(sender : AnyObject) {

    var request = NSMutableURLRequest(URL: NSURL(string: kLoginURL)) // Here, kLogin contains the Login API.

    var session = NSURLSession.sharedSession()

    request.HTTPMethod = "POST"

    var err: NSError?
    request.HTTPBody = NSJSONSerialization.dataWithJSONObject(self.criteriaDic(), options: nil, error: &err) // This Line fills the web service with required parameters.
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")

    var task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
        var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
        var err1: NSError?
        var json2 = NSJSONSerialization.JSONObjectWithData(strData.dataUsingEncoding(NSUTF8StringEncoding), options: .MutableLeaves, error:&err1 ) as NSDictionary

        println("json2 :\(json2)")

        if(err) {
            println(err!.localizedDescription)
        }
        else {
            var success = json2["success"] as? Int
            println("Success: \(success)")
        }
    })

    task.resume()
}

在这里，我为参数创建了一个单独的字典。

var params = ["format":"json", "MobileType":"IOS","MIN":"f8d16d98ad12acdbbe1de647414495ec","UserName":emailTxtField.text,"PWD":passwordTxtField.text,"SigninVia":"SH"]as NSDictionary
    return params
}

// You can add your own sets of parameter here.

我已经完成了HTTP请求两种方法GET和POST与JSON解析的方式:

在viewDidLoad ():

override func viewDidLoad() {
super.viewDidLoad()

    makeGetRequest()
    makePostRequest()

}

func makePostRequest(){

    let urlPath: String = "http://www.swiftdeveloperblog.com/http-post-example-script/"
    var url: NSURL = NSURL(string: urlPath)!
    var request: NSMutableURLRequest = NSMutableURLRequest(URL: url)

    request.HTTPMethod = "POST"
    var stringPost="firstName=James&lastName=Bond" // Key and Value

    let data = stringPost.dataUsingEncoding(NSUTF8StringEncoding)

    request.timeoutInterval = 60
    request.HTTPBody=data
    request.HTTPShouldHandleCookies=false

    let queue:NSOperationQueue = NSOperationQueue()

    NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse!, data: NSData!, error: NSError!) -> Void in
        var error: AutoreleasingUnsafeMutablePointer<NSError?> = nil
        let jsonResult: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.MutableContainers, error: error) as? NSDictionary

         if (jsonResult != nil) {
            // Success
           println(jsonResult)

           let message = jsonResult["Message"] as! NSString

           println(message)
         }else {
            // Failed
            println("Failed")
        }

    })

}

func makeGetRequest(){
    var url : String = "http://api.androidhive.info/contacts/"
    var request : NSMutableURLRequest = NSMutableURLRequest()
    request.URL = NSURL(string: url)
    request.HTTPMethod = "GET"
    request.timeoutInterval = 60

    NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse!, data: NSData!, error: NSError!) -> Void in
        var error: AutoreleasingUnsafeMutablePointer<NSError?> = nil
        let jsonResult: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.MutableContainers, error: error) as? NSDictionary

        if (jsonResult != nil) {
            // Success
            println(jsonResult)

            let dataArray = jsonResult["contacts"] as! NSArray;

            for item in dataArray { // loop through data items

                let obj = item as! NSDictionary

                for (key, value) in obj {

                    println("Key: \(key) - Value: \(value)")

                    let phone = obj["phone"] as! NSDictionary;

                    let mobile = phone["mobile"] as! NSString
                    println(mobile)
                    let home = phone["home"] as! NSString
                    println(home)
                    let office = phone["office"] as! NSString
                    println(office)
                }
            }

        } else {
            // Failed
            println("Failed")
        }

    })
}

Done

一个简单的Swift 2.0方法来发出HTTP GET请求

HTTP请求是异步的，因此需要一种方法从HTTP请求中获取返回值。这种方法使用通知器，分布在两个类中。

示例是使用网站http://www.example.com/handler.php?do=CheckUserJson&json=检查标识符令牌的用户名和密码，该文件名为handler.php，并且在do参数上有一个switch语句以获得RESTful方法。

在viewDidLoad中，我们设置了NotifierObserver，设置了json，并调用getHTTPRequest函数。它将返回函数checkedUsernameAndPassword和从http请求返回的参数。

override func viewDidLoad() {
    super.viewDidLoad()
    // setup the Notification observer to catch the result of check username and password
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "checkedUsernameAndPassword:", name: CHECK_USERNAME_AND_PASSWORD, object: nil)        
    let username = GlobalVariables.USER_NAME
    let password = GlobalVariables.PASSWORD
    // check username and password
    if let jsonString = Utility.checkUsernameAndPasswordJson(username, password:password){
        print("json string returned = \(jsonString)")
        let url = CHECKUSERJSON+jsonString
        // CHECKUSERJSON = http://www.example.com/handler.php?do=CheckUserJson&json=
        // jsonString = {\"username\":\"demo\",\"password\":\"demo\"}"
        // the php script handles a json request and returns a string identifier           
        Utility.getHTTPRequest(url,notifierId: CHECK_USERNAME_AND_PASSWORD)
        // the returned identifier is sent to the checkedUsernaeAndPassword function when it becomes availabel.
    }
}

在Utility.swift中有两个静态函数，首先用于编码json，然后执行HTTP调用。

    static func checkUsernameAndPasswordJson(username: String, password: String) -> String?{
    let para:NSMutableDictionary = NSMutableDictionary()
        para.setValue("demo", forKey: "username")
        para.setValue("demo", forKey: "password")
    let jsonData: NSData
    do{
        jsonData = try NSJSONSerialization.dataWithJSONObject(para, options: NSJSONWritingOptions())
        let jsonString = NSString(data: jsonData, encoding: NSUTF8StringEncoding) as! String
        return jsonString
    } catch _ {
        print ("UH OOO")
        return nil
    }
}

和Http请求

    static func getHTTPRequest (url:String , notifierId: String) -> Void{
    let urlString = url
    let config = NSURLSessionConfiguration.defaultSessionConfiguration()
    let session = NSURLSession(configuration: config, delegate: nil, delegateQueue: nil)
    let safeURL = urlString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!
    if let url = NSURL(string: safeURL){
        let request  = NSMutableURLRequest(URL: url)
        request.HTTPMethod = "GET"
        request.timeoutInterval = 60
        let taskData = session.dataTaskWithRequest(request, completionHandler: {
            (data:NSData?, response:NSURLResponse?, error:NSError?) -> Void in
            if (data != nil) {
                let result = NSString(data: data! , encoding: NSUTF8StringEncoding)
                sendNotification (notifierId, message: String(result), num: 0)
            }else{
                  sendNotification (notifierId, message: String(UTF8String: nil), num: -1)                    }
        })
    taskData.resume()
    }else{
        print("bad urlString = \(urlString)")
    }
}

sendNotification函数完成了循环。注意，在观察者中，在选择器字符串的末尾有一个“:”。这允许通知在userInfo中携带有效负载。我给它一个String和Int。

    static func sendNotification (key: String, message:String?, num: Int?){
    NSNotificationCenter.defaultCenter().postNotificationName(
        key,
        object: nil,
        userInfo:   (["message": message!,
                      "num": "\(num!)"])
    )
}

注意，使用HTTP是老式的，更喜欢HTTPS见我如何加载一个HTTP URL与应用程序传输安全启用在iOS 9?