Ios 具有NSURLSession的自定义NSURL协议

我正在尝试实现这个教程，它使用NSURLConnection实现了一个自定义的NSURL协议

它按预期工作，但现在在iOS9中不推荐使用NSURLConnection，我正试图将其转换为NSURLSession

不幸的是，它没有起作用

我在uiwebview中加载一个网站，如果我使用它加载的NSURLConnection，并且一切都按预期工作，则会捕获来自webview的所有http请求，但在使用NSURLSession时不会捕获

感谢您的帮助

这是我的密码

    import UIKit

    class MyProtocol: NSURLProtocol, NSURLSessionDataDelegate, NSURLSessionTaskDelegate, NSURLSessionDelegate {

    //var connection: NSURLConnection!
    var mutableData: NSMutableData!
    var response: NSURLResponse!

    var dataSession: NSURLSessionDataTask!

    override class func canInitWithRequest(request: NSURLRequest) -> Bool {

        if NSURLProtocol.propertyForKey("MyURLProtocolHandledKey", inRequest: request) != nil {
            return false
        }

        return true
    }

    override class func canonicalRequestForRequest(request: NSURLRequest) -> NSURLRequest {
        return request
    }

    override class func requestIsCacheEquivalent(aRequest: NSURLRequest,
        toRequest bRequest: NSURLRequest) -> Bool {
            return super.requestIsCacheEquivalent(aRequest, toRequest:bRequest)
    }

    override func startLoading() {
        let newRequest = self.request.mutableCopy() as! NSMutableURLRequest
        NSURLProtocol.setProperty(true, forKey: "MyURLProtocolHandledKey", inRequest: newRequest)

        self.dataSession = NSURLSession.sharedSession().dataTaskWithRequest(newRequest)

        dataSession.resume()
        self.mutableData = NSMutableData()
    }

        override func stopLoading() {

        print("Data task stop")
        self.dataSession.cancel()
        self.mutableData = nil

    }

    func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveResponse response: NSURLResponse, completionHandler: (NSURLSessionResponseDisposition) -> Void) {
        self.response = response
        self.mutableData = NSMutableData()
        print(mutableData)
    }

    func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveData data: NSData) {
        self.client?.URLProtocol(self, didLoadData: data)
        self.mutableData.appendData(data)
    }

    func URLSession(session: NSURLSession, task: NSURLSessionTask, didCompleteWithError error: NSError?) {
        if (error == nil)
        {
            self.client!.URLProtocolDidFinishLoading(self)
            self.saveCachedResponse()
        }
        else
        {
            self.client?.URLProtocol(self, didFailWithError: error!)
        }
    }

    func saveCachedResponse () {
        let timeStamp = NSDate()
        let urlString = self.request.URL?.absoluteString
        let dataString = NSString(data: self.mutableData, encoding: NSUTF8StringEncoding) as NSString?
        print("TiemStamp:\(timeStamp)\nURL: \(urlString)\n\nDATA:\(dataString)\n\n")
    }


    }

---

代码存在的问题是，您正在使用NSURLSession.sharedSession来包含数据任务。通过使用共享会话，您无法更改会话委托，因此不会调用任何委托例程

您将需要创建一个自定义会话，并将您的协议建立为该会话的代理。然后，当要求开始加载时，您可以在该会话中创建一个数据任务。

我已经解决了它

如果有人需要，这是代码

import Foundation

class MyProtocol1: NSURLProtocol, NSURLSessionDataDelegate, NSURLSessionTaskDelegate
{
private var dataTask:NSURLSessionDataTask?
private var urlResponse:NSURLResponse?
private var receivedData:NSMutableData?

class var CustomKey:String {
    return "myCustomKey"
}

// MARK: NSURLProtocol

override class func canInitWithRequest(request: NSURLRequest) -> Bool {
    if (NSURLProtocol.propertyForKey(MyProtocol1.CustomKey, inRequest: request) != nil) {
        return false
    }

    return true
}

override class func canonicalRequestForRequest(request: NSURLRequest) -> NSURLRequest {
    return request
}

override func startLoading() {

    let newRequest = self.request.mutableCopy() as! NSMutableURLRequest

    NSURLProtocol.setProperty("true", forKey: MyProtocol1.CustomKey, inRequest: newRequest)

    let defaultConfigObj = NSURLSessionConfiguration.defaultSessionConfiguration()
    let defaultSession = NSURLSession(configuration: defaultConfigObj, delegate: self, delegateQueue: nil)

    self.dataTask = defaultSession.dataTaskWithRequest(newRequest)
    self.dataTask!.resume()

}

override func stopLoading() {
    self.dataTask?.cancel()
    self.dataTask       = nil
    self.receivedData   = nil
    self.urlResponse    = nil
}

// MARK: NSURLSessionDataDelegate

func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask,
                didReceiveResponse response: NSURLResponse,
                                   completionHandler: (NSURLSessionResponseDisposition) -> Void) {

    self.client?.URLProtocol(self, didReceiveResponse: response, cacheStoragePolicy: .NotAllowed)

    self.urlResponse = response
    self.receivedData = NSMutableData()

    completionHandler(.Allow)
}

func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveData data: NSData) {
    self.client?.URLProtocol(self, didLoadData: data)

    self.receivedData?.appendData(data)
}

// MARK: NSURLSessionTaskDelegate

func URLSession(session: NSURLSession, task: NSURLSessionTask, didCompleteWithError error: NSError?) {
    if error != nil && error!.code != NSURLErrorCancelled {
        self.client?.URLProtocol(self, didFailWithError: error!)
    } else {
        saveCachedResponse()
        self.client?.URLProtocolDidFinishLoading(self)
    }
}

// MARK: Private methods

/**
 Do whatever with the data here
 */
func saveCachedResponse () {
    let timeStamp = NSDate()
    let urlString = self.request.URL?.absoluteString
    let dataString = NSString(data: self.receivedData!, encoding: NSUTF8StringEncoding) as NSString?
    print("TimeStamp:\(timeStamp)\nURL: \(urlString)\n\nDATA:\(dataString)\n\n")
}


}

Swift 3版本：

//  CustomURLProtocol.swift

class CustomURLProtocol: URLProtocol, URLSessionDataDelegate, URLSessionTaskDelegate {
  private var dataTask: URLSessionDataTask?
  private var urlResponse: URLResponse?
  private var receivedData: NSMutableData?

  class var CustomHeaderSet: String {
      return "CustomHeaderSet"
  }

  // MARK: NSURLProtocol

  override class func canInit(with request: URLRequest) -> Bool {
      guard let host = request.url?.host, host == "your domain.com" else {
          return false
      }
      if (URLProtocol.property(forKey: CustomURLProtocol.CustomHeaderSet, in: request as URLRequest) != nil) {
          return false
      }

      return true
  }

  override class func canonicalRequest(for request: URLRequest) -> URLRequest {
      return request
  }

  override func startLoading() {

      let mutableRequest =  NSMutableURLRequest.init(url: self.request.url!, cachePolicy: NSURLRequest.CachePolicy.useProtocolCachePolicy, timeoutInterval: 240.0)//self.request as! NSMutableURLRequest

      //Add User Agent

      var userAgentValueString = "myApp"
     mutableRequest.setValue(userAgentValueString, forHTTPHeaderField: "User-Agent")

      print(mutableRequest.allHTTPHeaderFields ?? "")
      URLProtocol.setProperty("true", forKey: CustomURLProtocol.CustomHeaderSet, in: mutableRequest)
      let defaultConfigObj = URLSessionConfiguration.default
      let defaultSession = URLSession(configuration: defaultConfigObj, delegate: self, delegateQueue: nil)
      self.dataTask = defaultSession.dataTask(with: mutableRequest as URLRequest)
      self.dataTask!.resume()

  }

  override func stopLoading() {
      self.dataTask?.cancel()
      self.dataTask       = nil
      self.receivedData   = nil
      self.urlResponse    = nil
  }

  // MARK: NSURLSessionDataDelegate

  func urlSession(_ session: URLSession, dataTask: URLSessionDataTask,
                  didReceive response: URLResponse,
                  completionHandler: @escaping (URLSession.ResponseDisposition) -> Void) {

      self.client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: .notAllowed)

      self.urlResponse = response
      self.receivedData = NSMutableData()

      completionHandler(.allow)
  }

  func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
      self.client?.urlProtocol(self, didLoad: data as Data)

      self.receivedData?.append(data as Data)
  }

  // MARK: NSURLSessionTaskDelegate

  func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
      if error != nil { //&& error.code != NSURLErrorCancelled {
          self.client?.urlProtocol(self, didFailWithError: error!)
      } else {
          //saveCachedResponse()
          self.client?.urlProtocolDidFinishLoading(self)
      }
  }
}

---

从URLSession的文档中：

重要

会话对象保留对委托的强引用，直到应用程序退出或显式使会话无效。如果您不使会话无效，您的应用程序将泄漏内存，直到退出

此外：

注意

注意不要创建超过需要的会话。例如，如果您的应用程序有几个部分需要类似配置的会话，请创建一个会话并在它们之间共享

因此，我将URLSession的创建从startLoading方法转移到URLProtocol子类初始值设定项：

class MyURLProtocol: URLProtocol, URLSessionDataDelegate,URLSessionTaskDelegate {
    override init(request: URLRequest, cachedResponse: CachedURLResponse?, client: URLProtocolClient?) {
        super.init(request: request, cachedResponse: cachedResponse, client: client)
        defaultSession = URLSession(configuration: .default, delegate: self, delegateQueue: nil)
    }
    private var defaultSession: URLSession?

---

你怎么知道你的代码不起作用？你自己做了什么来追踪这个问题？您能回顾一下您的代码示例并删除所有注释掉的部分吗？也许可以在每个例程中添加一些关于您试图完成的任务的注释。嘿，我是swift新手，面临webview缓存的问题。我尝试使用相同的源代码，正确加载网页并保存在缓存中。但当设备脱机时，我无法从缓存数据中获取它。可能我必须用urlsession更新代码。你能帮我找到这个来源吗（您好，感谢您的回复，注释掉的代码是针对NSURLConnection的，因为它在iOS9中已被弃用。我需要将其转换为NSURLSession，我要做的是监视来自uiwebview的所有http请求，并保存来自特定url请求的JSON响应。使用NSURLConnection时代码运行良好，但现在它已弃用。使用NSURLConnec我可以看到请求，webview会加载网站和单击的任何链接。但是，更改为NSURLSession后，webview不会加载网站。是的，我理解。正如我在回答中所说，当您使用NSURLConnection时，您为连接设置了代理，并且您的代理方法收集了数据。在新的NSURLSession中sed代码您需要创建一个自定义会话，而不是使用NSSession.sharedSession，这样您就可以在该会话上设置委托，从而可以调用您的会话和数据任务委托回调。嘿，scott thomson，您能告诉我如何使用惊人的加载（）吗当设备脱机显示缓存数据本地备份的方法？这是代码，我是Swift中的新手，有问题。tuman：谢谢。帮助很多。下面是SWIFT 3版本的同一个类，如果有人需要它。你不需要为每个请求使用一个单独的NSURLIST。这是非常低效的。你应该考虑USin。g单个共享实例（使用在dispatch_once块中初始化的全局变量）相反。是否可以截取来自移动文档目录的文件请求？它只截取带有http、https、，file:///var/container/... 但不是file:///var/mobile//Containers/Data/Application/...It正在运行，但显示完整的网站。不显示移动网站视图。