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