我正在尝试实现本教程，该教程使用NSURLConnection实现自定义NSURLProtocol。
https://www.raywenderlich.com/76735/using-nsurlprotocol-swift
它按预期工作，但现在在iOS9中不推荐使用NSURLConnection，我试图将其转换为NSURLSession。
不幸的是它不起作用。
我正在uiwebview中加载一个网站，如果我使用NSURLConnection加载并且一切正常工作，则会捕获来自webview的所有http请求，但不会在使用NSURLSession时。
感谢任何帮助。
这是我的代码
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")
}
}
答案 0 :(得分：11)
我已经解决了。
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")
}
}
答案 1 :(得分：6)
您使用代码时遇到的问题是您使用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。
您需要创建一个自定义会话，并将您的协议建立为会话的委托。然后，当要求开始加载时，您可以在该会话中创建数据任务。
答案 2 :(得分：6)
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)
}
}
}
答案 3 :(得分：0)
来自URLSession的文档：
重要
会话对象保留对委托的强引用，直到您的应用退出或显式使会话无效为止。如果您没有使会话无效，那么您的应用程序会在内存泄漏之前泄漏内存。
此外：
注意
小心不要创建超出需要的会话数。例如，如果您的应用程序的多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。
所以我将URLSession的创建从startLoading方法移动到URLProtocol子类初始化器：
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?