Alamofire 网络访问框架使用

框架概述

swift 版的 AFNetworking，提供了便利的在 swift 语言网络访问的框架。可以很容易的发起网络请求。

Alamofire结构

Alamofire.swift 主要是一些公用协议的声明和对外开放调用接口。主要使用此文件下的方法进行网络请求，里面封装了 网络请求、上传、下载等方法。还有一些扩展的。

Download.swift封装了关于下载的各种方法。

Manager.swfit是一个单列类，组装了访问的核心功能，Alamofire.swift也是调用此文件提供的方法。

ParameterEncoding.swift定义了参数的编码方式。

Request.swift拼装了 NSHttpRequest 请求。

UPload.swift定义了上传操作接口。

Validation.swift与权限有关

ResponseSerialization.swift回调相关的反序列化操作。

使用方法在后面

swift 的扩展特性是我们使用 Alamofire 更加的方便，在得到网络请求后，可以进行进一步对数据的操作。更贴切面向对象的思想，比较方便的就是对 Request 进行扩展，拿到不一样的数据后可以进行相应的处理后在返回。

进行扩展

如下代码分别对返回的数据做出了不同处理

//对返回的数据为集合类进行处理
extension Alamofire.Request{
public func responseCollection<T: ResponseCollectionSerializable>(completionHandler: (NSURLRequest, NSHTTPURLResponse?, [T]?, NSError?) -> Void) ->Self{

let responseSerializer = GenericResponseSerializer<[T]> {request,response,data in
let JSONResponseSerializer = Request.JSONResponseSerializer(options: .AllowFragments)
let (JSON:AnyObject?,serializationError) = JSONResponseSerializer.serializeResponse(request,response,data)

if let response = response,JSON:AnyObject = JSON {

return (T.collection(response: response, representation: JSON), nil)

}else{
return(nil,serializationError)
}
}
return response(responseSerializer: responseSerializer, completionHandler: completionHandler)
}
}

@objc public protocol ResponseObjectSerializable{
init?(response:NSHTTPURLResponse, representation:AnyObject)
}

//对 JSON 数据进行处理
extension Alamofire.Request{
public func responseObject<T:ResponseObjectSerializable>(completionHandler:(NSURLRequest,NSHTTPURLResponse?,T?,NSError?) ->Void ) ->Self {
let responseSerializer = GenericResponseSerializer<T>{request,response,data in
let JSONResponseSerializer = Request.JSONResponseSerializer(options: .AllowFragments)
let (JSON:AnyObject?,serializerError) = JSONResponseSerializer.serializeResponse(request,response,data)

if let response = response, JSON:AnyObject = JSON{
return (T(response: response, representation: JSON),nil)
}else{
return(nil,serializerError)
}
}
return response(responseSerializer:responseSerializer,completionHandler:completionHandler)
}
}

//对返回的图片数据进行处理
extension Alamofire.Request {
public static func imageResponseSerializer() -> GenericResponseSerializer<UIImage> {
return GenericResponseSerializer { request, response, data in
if data == nil {
return (nil, nil)
}

let image = UIImage(data: data!, scale: UIScreen.mainScreen().scale)

return (image, nil)
}
}

public func responseImage(completionHandler: (NSURLRequest, NSHTTPURLResponse?, UIImage?, NSError?) -> Void) -> Self {
return response(responseSerializer: Request.imageResponseSerializer(), completionHandler: completionHandler)
}
}

扩展后的使用

Alamofire.request(.GET, photoInfo!.url).validate().responseImage() {
(_, _, image, error) in

if error == nil && image != nil {
self.imageView.image = image
self.imageView.frame = self.centerFrameFromImage(image)

self.spinner.stopAnimating()

self.centerScrollViewContents()
}
}

使用方法

以下内容为摘取 github 上给出的文档实例。

GET 请求

Alamofire.request(.GET, "http://httpbin.org/get")

带参数

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
Response结果处理
Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
.response { (request, response, data, error) in
println(request)
println(response)
println(error)
}
Response结果字符串处理
Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
.responseString { (request, response, string, error) in
println(string)
}

HTTP 方法（Medthods）

Alamofire.Method enum 列表出在RFC 2616中定义的HTTP方法 §9:

public enum Method: String {
case OPTIONS = "OPTIONS"
case GET = "GET"
case HEAD = "HEAD"
case POST = "POST"
case PUT = "PUT"
case PATCH = "PATCH"
case DELETE = "DELETE"
case TRACE = "TRACE"
case CONNECT = "CONNECT"
}

这些值可以作为Alamofire.request请求的第一个参数.

Alamofire.request(.POST, "http://httpbin.org/post")

Alamofire.request(.PUT, "http://httpbin.org/put")

Alamofire.request(.DELETE, "http://httpbin.org/delete")

POST请求

let parameters = [
"foo": "bar",
"baz": ["a", 1],
"qux": [
"x": 1,
"y": 2,
"z": 3
]
]

Alamofire.request(.POST, "http://httpbin.org/post", parameters: parameters)

发送以下HttpBody内容:

foo=bar&baz[]=a&baz[]=1&qux[x]=1&qux[y]=2&qux[z]=3

Alamofire 使用Alamofire.ParameterEncoding可以支持URL query/URI form,JSON, PropertyList方式编码参数。

Parameter Encoding

enum ParameterEncoding {
case URL
case JSON(options: NSJSONWritingOptions)
case PropertyList(format: NSPropertyListFormat,
options: NSPropertyListWriteOptions)

func encode(request: NSURLRequest,
parameters: [String: AnyObject]?) ->
(NSURLRequest, NSError?)
{ ... }
}

NSURLRequest方式编码参数

let URL = NSURL(string: "http://httpbin.org/get")
var request = NSURLRequest(URL: URL)

let parameters = ["foo": "bar"]
let encoding = Alamofire.ParameterEncoding.URL
(request, _) = encoding.encode(request, parameters)
POST JSON格式数据
Alamofire.request(.POST, "http://httpbin.org/post", parameters: parameters, encoding: .JSON(options: nil))
.responseJSON {(request, response, JSON, error) in
println(JSON)
}

Response 方法

response()
responseString(encoding: NSStringEncoding)
responseJSON(options: NSJSONReadingOptions)
responsePropertyList(options: NSPropertyListReadOptions)

上传（Uploading）

支持的类型

File

Data

Stream

Multipart (Coming Soon)

上传文件

let fileURL = NSBundle.mainBundle()
.URLForResource("Default",
withExtension: "png")

Alamofire.upload(.POST, "http://httpbin.org/post", file: fileURL)

上传进度

Alamofire.upload(.POST, "http://httpbin.org/post", file: fileURL)
.progress { (bytesWritten, totalBytesWritten, totalBytesExpectedToWrite) in
println(totalBytesWritten)
}
.responseJSON { (request, response, JSON, error) in
println(JSON)
}

下载

支持的类型

Request

Resume Data

下载文件

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: { (temporaryURL, response) in
if let directoryURL = NSFileManager.defaultManager()
.URLsForDirectory(.DocumentDirectory,
inDomains: .UserDomainMask)[0]
as? NSURL {
let pathComponent = response.suggestedFilename

return directoryURL.URLByAppendingPathComponent(pathComponent)
}

return temporaryURL
})

下载到默认路径

let destination = Alamofire.Request.suggestedDownloadDestination(directory: .DocumentDirectory, domain: .UserDomainMask)

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: destination)

下载进度

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: destination)
.progress { (bytesRead, totalBytesRead, totalBytesExpectedToRead) in
println(totalBytesRead)
}
.response { (request, response, _, error) in
println(response)
}

认证（Authentication）

支持以下几种认证

HTTP Basic

HTTP Digest

Kerberos

NTLM

Http basic认证

let user = "user"
let password = "password"

Alamofire.request(.GET, "https://httpbin.org/basic-auth/\(user)/\(password)")
.authenticate(HTTPBasic: user, password: password)
.response {(request, response, _, error) in
println(response)
}

采用NSURLCredential&NSURLProtectionSpace方式认证

let user = "user"
let password = "password"

let credential = NSURLCredential(user: user, password: password, persistence: .ForSession)
let protectionSpace = NSURLProtectionSpace(host: "httpbin.org", port: 0, `protocol`: "https", realm: nil, authenticationMethod: NSURLAuthenticationMethodHTTPBasic)
Alamofire.request(.GET, "https://httpbin.org/basic-auth/\(user)/\(password)")
.authenticate(usingCredential: credential, forProtectionSpace: protectionSpace)
.response {(request, response, _, error) in
println(response)
}

调试

let request = Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])

debugPrintln(request)
Output (cURL)

$ curl -i \
-H "User-Agent: Alamofire" \
-H "Accept-Encoding: Accept-Encoding: gzip;q=1.0,compress;q=0.5" \
-H "Accept-Language: en;q=1.0,fr;q=0.9,de;q=0.8,zh-Hans;q=0.7,zh-Hant;q=0.6,ja;q=0.5" \
"http://httpbin.org/get?foo=bar"