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
另一个选择是Alamofire库,它提供了可链请求/响应方法。
https://github.com/Alamofire/Alamofire
提出请求
import Alamofire
Alamofire.request(.GET, "http://httpbin.org/get")
响应处理
Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
.response { request, response, data, error in
print(request)
print(response)
print(error)
}
其他回答
//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'];
Swift 4及以上:使用URLSession API进行数据请求
// create the url
let url = URL(string: "https://jsonplaceholder.typicode.com/todos/1")! //change the url
// create the session object
let session = URLSession.shared
// now create the URLRequest object using the url object
let request = URLRequest(url: url)
// create dataTask using the session object to send data to the server
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
guard error == nil else {
return
}
guard let data = data else {
return
}
do {
//create json object from data
if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
print(json)
}
} catch let error {
print(error.localizedDescription)
}
})
task.resume()
Swift 4及以上,可解码和结果enum
// APIError enum which shows all possible Network errors
enum APIError: Error {
case networkError(Error)
case dataNotFound
case jsonParsingError(Error)
case invalidStatusCode(Int)
case badURL(String)
}
// Result enum to show success or failure
enum Result<T> {
case success(T)
case failure(AppError)
}
// dataRequest which sends request to given URL and convert to Decodable Object
func dataRequest<T: Decodable>(with url: String, objectType: T.Type, completion: @escaping (Result<T>) -> Void) {
// create the url with NSURL
guard let dataURL = URL(string: url) else {
completion(.failure(APIError.badURL(url))
return
}
// create the session object
let session = URLSession.shared
// now create the URLRequest object using the url object
let request = URLRequest(url: dataURL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 60)
// create dataTask using the session object to send data to the server
let task = session.dataTask(with: request, completionHandler: { data, response, error in
guard error == nil else {
completion(Result.failure(APIError.networkError(error!)))
return
}
guard let data = data else {
completion(Result.failure(AppError.dataNotFound))
return
}
do {
// create decodable object from data
let decodedObject = try JSONDecoder().decode(objectType.self, from: data)
completion(Result.success(decodedObject))
} catch let error {
completion(Result.failure(APIError.jsonParsingError(error as! DecodingError)))
}
})
task.resume()
}
例子:
//如果我们想从占位符API获取todo,那么我们定义todo结构体并调用dataRequest并传递“https://jsonplaceholder.typicode.com/todos/1”字符串url。
struct ToDo: Decodable {
let id: Int
let userId: Int
let title: String
let completed: Bool
}
dataRequest(with: "https://jsonplaceholder.typicode.com/todos/1", objectType: ToDo.self) { (result: Result) in
switch result {
case .success(let object):
print(object)
case .failure(let error):
print(error)
}
}
//输出结果:
ToDo(id: 1, userId: 1, title: "delectus aut autem", completed: false)
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
斯威夫特3.0
通过一个小抽象 https://github.com/daltoniam/swiftHTTP
例子
do {
let opt = try HTTP.GET("https://google.com")
opt.start { response in
if let err = response.error {
print("error: \(err.localizedDescription)")
return //also notify app of failure as needed
}
print("opt finished: \(response.description)")
//print("data is: \(response.data)") access the response of the data with response.data
}
} catch let error {
print("got an error creating the request: \(error)")
}
更新:Xcode 13.0和Swift 5+
获取HTTP请求
let url = URL(string: "URL HERE")! //PUT Your URL
var request = URLRequest(url: url)
request.httpMethod = "GET"
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let safeData = data,
let response = response as? HTTPURLResponse,
error == nil else { // check for fundamental networking error
print("error", error ?? "Unknown error")
delegate?.onError(error!)
return
}
guard (200 ... 299) ~= response.statusCode else { // check for http errors
print("statusCode should be 2xx, but is \(response.statusCode)")
print("response = \(response)")
return
}
let responseString = String(data: safeData, encoding: .utf8)
print("Response String = \(responseString)")
}
task.resume()
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