我在iBooks上读了苹果的编程语言Swift,但不知道如何在Swift中发出HTTP请求(类似cURL)。我需要导入Obj-C类还是只需要导入默认库?或者不能基于原生Swift代码进行HTTP请求?


当前回答

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()

其他回答

检查以下代码:

1. SynchonousRequest

斯威夫特1.2

    let urlPath: String = "YOUR_URL_HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request1: NSURLRequest = NSURLRequest(URL: url)
    var response: AutoreleasingUnsafeMutablePointer<NSURLResponse?>=nil
    var dataVal: NSData =  NSURLConnection.sendSynchronousRequest(request1, returningResponse: response, error:nil)!
    var err: NSError
    println(response)
    var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataVal, options: NSJSONReadingOptions.MutableContainers, error: &err) as? NSDictionary
    println("Synchronous\(jsonResult)")

快速2.0 +

let urlPath: String = "YOUR_URL_HERE"
    let url: NSURL = NSURL(string: urlPath)!
    let request1: NSURLRequest = NSURLRequest(URL: url)
    let response: AutoreleasingUnsafeMutablePointer<NSURLResponse?>=nil


    do{

        let dataVal = try NSURLConnection.sendSynchronousRequest(request1, returningResponse: response)

            print(response)
            do {
                if let jsonResult = try NSJSONSerialization.JSONObjectWithData(dataVal, options: []) as? NSDictionary {
                    print("Synchronous\(jsonResult)")
                }
            } catch let error as NSError {
                print(error.localizedDescription)
            }



    }catch let error as NSError
    {
         print(error.localizedDescription)
    }

2. AsynchonousRequest

斯威夫特1.2

let urlPath: String = "YOUR_URL_HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request1: NSURLRequest = NSURLRequest(URL: url)
    let queue:NSOperationQueue = NSOperationQueue()
    NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in
        var err: NSError
        var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
        println("Asynchronous\(jsonResult)")
       })

快速2.0 +

let urlPath: String = "YOUR_URL_HERE"
    let url: NSURL = NSURL(string: urlPath)!
    let request1: NSURLRequest = NSURLRequest(URL: url)
    let queue:NSOperationQueue = NSOperationQueue()

    NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse?, data: NSData?, error: NSError?) -> Void in

        do {
            if let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? NSDictionary {
                print("ASynchronous\(jsonResult)")
            }
        } catch let error as NSError {
            print(error.localizedDescription)
        }


    })

3.和往常一样,URL连接

斯威夫特1.2

    var dataVal = NSMutableData()
    let urlPath: String = "YOUR URL HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request: NSURLRequest = NSURLRequest(URL: url)
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: true)!
    connection.start()

Then

 func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
    self.dataVal?.appendData(data)
}


func connectionDidFinishLoading(connection: NSURLConnection!)
{
    var error: NSErrorPointer=nil

    var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataVal!, options: NSJSONReadingOptions.MutableContainers, error: error) as NSDictionary

    println(jsonResult)



}

快速2.0 +

   var dataVal = NSMutableData()
    let urlPath: String = "YOUR URL HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request: NSURLRequest = NSURLRequest(URL: url)
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: true)!
    connection.start()

Then

func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
    dataVal.appendData(data)
}


func connectionDidFinishLoading(connection: NSURLConnection!)
{

    do {
        if let jsonResult = try NSJSONSerialization.JSONObjectWithData(dataVal, options: []) as? NSDictionary {
            print(jsonResult)
        }
    } catch let error as NSError {
        print(error.localizedDescription)
    }

}

4. 异步POST请求

斯威夫特1.2

    let urlPath: String = "YOUR URL HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request1: NSMutableURLRequest = NSMutableURLRequest(URL: url)

    request1.HTTPMethod = "POST"
     var stringPost="deviceToken=123456" // Key and Value

    let data = stringPost.dataUsingEncoding(NSUTF8StringEncoding)

    request1.timeoutInterval = 60
    request1.HTTPBody=data
    request1.HTTPShouldHandleCookies=false

    let queue:NSOperationQueue = NSOperationQueue()

     NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in


        var err: NSError

        var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
        println("AsSynchronous\(jsonResult)")


        })

快速2.0 +

let urlPath: String = "YOUR URL HERE"
    let url: NSURL = NSURL(string: urlPath)!
    let request1: NSMutableURLRequest = NSMutableURLRequest(URL: url)

    request1.HTTPMethod = "POST"
    let stringPost="deviceToken=123456" // Key and Value

    let data = stringPost.dataUsingEncoding(NSUTF8StringEncoding)

    request1.timeoutInterval = 60
    request1.HTTPBody=data
    request1.HTTPShouldHandleCookies=false

    let queue:NSOperationQueue = NSOperationQueue()

    NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse?, data: NSData?, error: NSError?) -> Void in

        do {
            if let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? NSDictionary {
                print("ASynchronous\(jsonResult)")
            }
        } catch let error as NSError {
            print(error.localizedDescription)
        }


    })

5. 异步GET请求

斯威夫特1.2

    let urlPath: String = "YOUR URL HERE"
    var url: NSURL = NSURL(string: urlPath)!
    var request1: NSMutableURLRequest = NSMutableURLRequest(URL: url)

    request1.HTTPMethod = "GET"
    request1.timeoutInterval = 60
    let queue:NSOperationQueue = NSOperationQueue()

     NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in


        var err: NSError

        var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
        println("AsSynchronous\(jsonResult)")


        })

快速2.0 +

let urlPath: String = "YOUR URL HERE"
    let url: NSURL = NSURL(string: urlPath)!
    let request1: NSMutableURLRequest = NSMutableURLRequest(URL: url)

    request1.HTTPMethod = "GET"
    let queue:NSOperationQueue = NSOperationQueue()

    NSURLConnection.sendAsynchronousRequest(request1, queue: queue, completionHandler:{ (response: NSURLResponse?, data: NSData?, error: NSError?) -> Void in

        do {
            if let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? NSDictionary {
                print("ASynchronous\(jsonResult)")
            }
        } catch let error as NSError {
            print(error.localizedDescription)
        }


    })

6. 上传图片(文件)

快速2.0 +

  let mainURL = "YOUR_URL_HERE"

    let url = NSURL(string: mainURL)
    let request = NSMutableURLRequest(URL: url!)
    let boundary = "78876565564454554547676"
    request.addValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")


    request.HTTPMethod = "POST" // POST OR PUT What you want
    let session = NSURLSession(configuration:NSURLSessionConfiguration.defaultSessionConfiguration(), delegate: nil, delegateQueue: nil)

    let imageData = UIImageJPEGRepresentation(UIImage(named: "Test.jpeg")!, 1)





    var body = NSMutableData()

    body.appendData("--\(boundary)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

    // Append your parameters

    body.appendData("Content-Disposition: form-data; name=\"name\"\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
    body.appendData("PREMKUMAR\r\n".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)!)
    body.appendData("--\(boundary)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

    body.appendData("Content-Disposition: form-data; name=\"description\"\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
    body.appendData("IOS_DEVELOPER\r\n".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)!)
    body.appendData("--\(boundary)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)


    // Append your Image/File Data

    var imageNameval = "HELLO.jpg"

    body.appendData("--\(boundary)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
    body.appendData("Content-Disposition: form-data; name=\"profile_photo\"; filename=\"\(imageNameval)\"\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
    body.appendData("Content-Type: image/jpeg\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
    body.appendData(imageData!)
    body.appendData("\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

    body.appendData("--\(boundary)--\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

    request.HTTPBody = body




    let dataTask = session.dataTaskWithRequest(request) { (data, response, error) -> Void in

        if error != nil {

            //handle error


        }
        else {




            let outputString : NSString = NSString(data:data!, encoding:NSUTF8StringEncoding)!
            print("Response:\(outputString)")


        }
    }
    dataTask.resume()

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.

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!!

为了让XCUITest在异步请求完成之前停止测试完成,使用这个(可能会减少100超时):

func test_api() {
    let url = URL(string: "https://jsonplaceholder.typicode.com/posts/42")!
    let exp = expectation(description: "Waiting for data")
    let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
        guard let data = data else { return }
        print(String(data: data, encoding: .utf8)!)
        exp.fulfill()
    }
    task.resume()
    XCTWaiter.wait(for: [exp], timeout: 100)
}

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) }