我的问题与此问题非常相似,但对于Alamofire:AFNetworking: Handle error globally and repeat request
如何能够捕获全局错误(通常是401)并在发出其他请求之前处理它(如果不管理则最终会失败)?
我正在考虑链接自定义响应处理程序,但在应用程序的每个请求上执行此操作都很愚蠢。
也许是子类化,但是我应该将哪个类子类化来处理它?</ p>
答案 0 :(得分:95)
考虑到NSURLSessions的并行特性,在oauth流中处理401响应的刷新非常复杂。我花了很多时间构建一个对我们来说非常好的内部解决方案。以下是对如何实施它的一般概念的非常高级别的提取。
import Foundation
import Alamofire
public class AuthorizationManager: Manager {
public typealias NetworkSuccessHandler = (AnyObject?) -> Void
public typealias NetworkFailureHandler = (NSHTTPURLResponse?, AnyObject?, NSError) -> Void
private typealias CachedTask = (NSHTTPURLResponse?, AnyObject?, NSError?) -> Void
private var cachedTasks = Array<CachedTask>()
private var isRefreshing = false
public func startRequest(
method method: Alamofire.Method,
URLString: URLStringConvertible,
parameters: [String: AnyObject]?,
encoding: ParameterEncoding,
success: NetworkSuccessHandler?,
failure: NetworkFailureHandler?) -> Request?
{
let cachedTask: CachedTask = { [weak self] URLResponse, data, error in
guard let strongSelf = self else { return }
if let error = error {
failure?(URLResponse, data, error)
} else {
strongSelf.startRequest(
method: method,
URLString: URLString,
parameters: parameters,
encoding: encoding,
success: success,
failure: failure
)
}
}
if self.isRefreshing {
self.cachedTasks.append(cachedTask)
return nil
}
// Append your auth tokens here to your parameters
let request = self.request(method, URLString, parameters: parameters, encoding: encoding)
request.response { [weak self] request, response, data, error in
guard let strongSelf = self else { return }
if let response = response where response.statusCode == 401 {
strongSelf.cachedTasks.append(cachedTask)
strongSelf.refreshTokens()
return
}
if let error = error {
failure?(response, data, error)
} else {
success?(data)
}
}
return request
}
func refreshTokens() {
self.isRefreshing = true
// Make the refresh call and run the following in the success closure to restart the cached tasks
let cachedTaskCopy = self.cachedTasks
self.cachedTasks.removeAll()
cachedTaskCopy.map { $0(nil, nil, nil) }
self.isRefreshing = false
}
}
这里要记住的最重要的事情是,您不希望为每个返回的401运行刷新调用。大量请求可以同时竞赛。因此,您希望对第一个401执行操作,并将所有其他请求排入队列,直到401成功为止。我上面概述的解决方案确实如此。通过startRequest
方法启动的任何数据任务将在达到401时自动刷新。
这个非常简单的例子中没有考虑的其他重要事项是:
希望这有助于解决问题。
我们现在发布了Alamofire 4.0,它添加了RequestAdapter
和RequestRetrier
协议,无论授权实现细节如何,您都可以轻松构建自己的身份验证系统!有关详情,请参阅我们的README,其中提供了有关如何在您的应用中实施OAuth2系统的完整示例。
完全披露:自述文件中的示例仅用作示例。请不要只是将代码复制粘贴到生产应用程序中。
答案 1 :(得分:0)
在Alamofire 5中,您可以使用RequestInterceptor 这是我在我的一个项目中对401错误的错误处理,如果请求出错,则我将通过EnvironmentInterceptor传递给它的每个请求都将调用重试功能 并且Adapt函数可以帮助您向请求中添加默认值
struct EnvironmentInterceptor: RequestInterceptor {
func adapt(_ urlRequest: URLRequest, for session: Session, completion: @escaping (AFResult<URLRequest>) -> Void) {
var adaptedRequest = urlRequest
guard let token = KeychainWrapper.standard.string(forKey: KeychainsKeys.token.rawValue) else {
completion(.success(adaptedRequest))
return
}
adaptedRequest.setValue("Bearer \(token)", forHTTPHeaderField: HTTPHeaderField.authentication.rawValue)
completion(.success(adaptedRequest))
}
func retry(_ request: Request, for session: Session, dueTo error: Error, completion: @escaping (RetryResult) -> Void) {
if let response = request.task?.response as? HTTPURLResponse, response.statusCode == 401 {
//get token
guard let refreshToken = KeychainWrapper.standard.string(forKey: KeychainsKeys.refreshToken.rawValue) else {
completion(.doNotRetryWithError(error))
return
}
APIDriverAcountClient.refreshToken(refreshToken: refreshToken) { res in
switch res {
case .success(let response):
let saveAccessToken: Bool = KeychainWrapper.standard.set(response.accessToken, forKey: KeychainsKeys.token.rawValue)
let saveRefreshToken: Bool = KeychainWrapper.standard.set(response.refreshToken, forKey: KeychainsKeys.refreshToken.rawValue)
let saveUserId: Bool = KeychainWrapper.standard.set(response.userId, forKey: KeychainsKeys.uId.rawValue)
print("is accesstoken saved ?: \(saveAccessToken)")
print("is refreshToken saved ?: \(saveRefreshToken)")
print("is userID saved ?: \(saveUserId)")
completion(.retry)
break
case .failure(let err):
//TODO logout
break
}
}
} else {
completion(.doNotRetry)
}
}
,您可以像这样使用它:
@discardableResult
private static func performRequest<T: Decodable>(route: ApiDriverTrip, decoder: JSONDecoder = JSONDecoder(), completion: @escaping (AFResult<T>)->Void) -> DataRequest {
return AF.request(route, interceptor: EnvironmentInterceptor())
.responseDecodable (decoder: decoder){ (response: DataResponse<T>) in
completion(response.result)
}