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
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!!
其他回答
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()
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()
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()
下面给出了一个“GET”请求示例。
let urlString = "YOUR_GET_URL"
let yourURL = URL(string: urlstring)
let dataTask = URLSession.shared.dataTask(with: yourURL) { (data, response, error) in
do {
let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers)
print("json --- \(json)")
}catch let err {
print("err---\(err.localizedDescription)")
}
}
dataTask.resume()
你可以使用URL URLRequest URLSession或者NSURLConnection就像你在Objective-C中通常做的那样。注意，对于iOS 7.0及更高版本，URLSession是首选。
使用URLSession
初始化URL对象和URLSession中的URLSessionDataTask。然后使用resume()运行任务。
let url = URL(string: "http://www.stackoverflow.com")!
let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
guard let data = data else { return }
print(String(data: data, encoding: .utf8)!)
}
task.resume()
使用NSURLConnection
首先，初始化URL和URLRequest:
let url = URL(string: "http://www.stackoverflow.com")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
然后，你可以异步加载请求:
NSURLConnection.sendAsynchronousRequest(request, queue: OperationQueue.main) {(response, data, error) in
guard let data = data else { return }
print(String(data: data, encoding: .utf8)!)
}
或者你可以初始化一个NSURLConnection:
let connection = NSURLConnection(request: request, delegate:nil, startImmediately: true)
只是要确保将委托设置为nil以外的东西，并使用委托方法处理接收到的响应和数据。
要了解更多细节，请查看NSURLConnectionDataDelegate协议的文档
在Xcode操场上测试
如果你想在Xcode游乐场上尝试这段代码，添加import PlaygroundSupport到你的游乐场，以及下面的调用:
PlaygroundPage.current.needsIndefiniteExecution = true
这将允许你在操场上使用异步代码。
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