ios - URlRequest.httpBody 在 startLoading() 方法中是 nil swift 3.0 中的 URLProtocol

Question

我有我的自定义 URLProtocol，它有一些自定义响应生成。现在我有一个要求，我需要在获得实际响应之前通过 httpBody 向服务器发送一些信息(可以是 json/String 作为数据)

我的问题是，当我使用 httpBody 创建 urlRequest 时，然后通过使用 URLSession 和一些 session 配置(那个自定义 URLProtocol 包含在这里)

这将首先调用 canInit -> canonical -> startLoading -> stopLoading，在这些所有方法中，request.httpBody 为 nil。

override func startLoading() {
        let request = self.request
        var response: HTTPURLResponse?
        let hasResponse: Bool = true
        if request.httpMethod == "GET" || request.httpMethod == "POST" {
            guard let url = request.url else {
                return
            }
            let client = self.client
            let statusCode = 200
            if url.absoluteString.contains("/good") {
                print(self.request.httpBody)  //here its nil
            } 
            response = hasResponse ? HTTPURLResponse(url: request.url!, statusCode: statusCode, httpVersion: "HTTP/1.1", headerFields: cannedHeaders) : nil
            client?.urlProtocol(self, didLoad: responseData)
            client?.urlProtocol(self, didReceive: response!, cacheStoragePolicy: URLCache.StoragePolicy.notAllowed)
            client?.urlProtocolDidFinishLoading(self)
        }
    }
func testCompressRequest() {
        let expect = expectation(description: "testCompressRequest")
        let urlRequest = URLRequest(url: URL(string:serverPath+"/good")!)
        urlRequest.httpBody = "someMethodBodyasString".data(using: .utf8)
        urlRequest.httpMethod = "POST"
        urlRequest.allHTTPHeaderFields = ["Accept-Encoding": "gzip, deflate", "Content-Encoding":"gzip, deflate", "Content-Type":"application/json", "Accept":"application/json", "Content-Length":String(describing: urlRequest.httpBody?.count)]
        let task = URLSession(configuration: sessionConfig).dataTask(with: urlRequest) { (data, response, error) in
            expect.fulfill()
        }
        task.resume()
        waitForExpectations(timeout: 10, handler: nil)
    }

Answer 1

当协议(protocol)看到请求对象时，正文数据对象已经被标准化为正文流对象。打开正文流并从那里读取数据。