AFNetworking 2.0/Boost::Asio - 获取 JSON 数据（网络连接丢失）

Question

我已使用 AFHTTPRequestOperationManager 成功地将 JSON 数据发送到 BOOST Asio，但未能成功检索 JSON 数据。我确实确保我可以通过 AFNetworking 中的 Reachability 功能联系到主机。我已经尝试了几个基于 AFHTTPRequestOperationManager 的函数，例如：

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.securityPolicy.allowInvalidCertificates=YES;
manager.responseSerializer = [AFJSONResponseSerializer serializer];
[manager POST:@"http://xx.xx.xx.x:8888"
  parameters:nil
     success:^(AFHTTPRequestOperation *operation, id responseObject) {
         NSLog(@"JSON: %@", responseObject);
     } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
         NSLog(@"Error: %@", error);
     }];

但是，我一直收到同样的错误：

Error Domain=NSURLErrorDomain Code=-1005 "网络连接是 丢失。” UserInfo={NSUnderlyingError=0x12fd7c580 {错误 Domain=kCFErrorDomainCFNetwork Code=-1005 "网络连接是 丢失。” UserInfo={NSErrorFailingURLStringKey=http:/xx.xx.xx.x:8888/, _kCFStreamErrorDomainKey=1，NSErrorPeerAddressKey={长度=16，容量=16，字节= 0x100222b82d3741040000000000000000}，_kCFStreamErrorCodeKey=54， NSErrorFailingURLKey=http://xx.xx.xx.x:8888/, NSLocalizedDescription=网络连接丢失。}}, NSErrorFailingURLStringKey=http://xx.xx.xx.x:8888/, NSErrorFailingURLKey=http://xx.xx.xx.x:8888/, _kCFStreamErrorDomainKey=1, _kCFStreamErrorCodeKey=54, NSLocalizedDescription=网络连接丢失。}

Linux 服务器示例利用 Boost Asio async_write 功能和写入处理程序来确保 JSON POST 完成。

#include <boost/asio.hpp>
#include <boost/thread.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <boost/bind.hpp>
#include <iostream>
#include <string>
#include <boost/property_tree/json_parser.hpp>
#include <boost/property_tree/ptree.hpp>

using boost::property_tree::ptree;
using boost::property_tree::basic_ptree;

using boost::asio::ip::tcp;
using namespace std;

typedef std::string Blob;
const std::string NOOBJECT = "a";

class Server : public boost::enable_shared_from_this<Server> {
private:
    const std::string AUTHSVCS = "xx.xx.xx.x:8888";

public:
    Server();
    virtual ~Server();
    void send(tcp::socket&, boost::asio::io_service&, std::string&);
    void on_send(const boost::system::error_code &, size_t);
    void genheader(Blob& body, std::string& request);
    void genbody(const std::string& reqtype, Blob& token, Blob& body);
};

Server::Server() {
}

Server::~Server() {
}

void
Server::genheader(Blob& body, std::string& request)
{
    cout << "Server::genheader" << endl;

    request += "POST / HTTP/1.1 \r\n";
    request += "Host:";
    request += AUTHSVCS;
    request += "\r\n";
    request += "User-Agent: ProteAuth/1.0 \r\n";
    request += "Content-Type: application/json; charset=utf-8 \r\n";
    request   += "Content-Type: application/json \r\n";
    request += "Accept: */*\r\n";
    request += "Content-Length: ";
    request += std::to_string(body.length());
    request += "\r\n";
    request += "Connection: close\r\n\r\n";
    request += body;
}

void
Server::genbody(const std::string& reqtype, Blob& token, Blob& body)
{
    ptree requestTree;
    ptree requestElement;

    std::cout << "Server::genbody" << std::endl;

    // Add request token
    requestElement.put_value(token);
    requestTree.add_child(reqtype, requestElement);

    // Create (JSON) request
    std::stringstream ss;
    write_json(ss, requestTree, false);
    body = ss.str();
}

void
Server::send(tcp::socket& sock, boost::asio::io_service& io_service, std::string& request) {
    std::cout << "Server::send" << std::endl;

    try {
        async_write(sock, boost::asio::buffer(request), boost::bind(
                &Server::on_send,
                shared_from_this(),
                boost::asio::placeholders::error,
                boost::asio::placeholders::bytes_transferred));

        io_service.run();
    } catch (exception& e) {
        std::cerr << e.what() << std::endl;
    }

    return;
}
void
Server::on_send(const boost::system::error_code & error, size_t bytes_transferred) {
    std::cout << "Server::on_send" << std::endl;

    if (error) {
        std::cout << "Error: " << error.message() << std::endl;
        std::cout << "Bytes sent: " << bytes_transferred << std::endl;
    } else {
        std::cout << "Bytes sent: " << bytes_transferred << std::endl;
    }

    return;
}

int main() {
    try {
        boost::asio::io_service ioserv;
        tcp::acceptor acceptor(ioserv, tcp::endpoint(tcp::v4(), 8888));
        boost::shared_ptr<Server> sesh(new Server());

        //Blob 
        Blob token("a");

        // Generate URL body
        Blob body;
        sesh->genbody(NOOBJECT, token, body);

        // Generate Headers (append body)
        std::string request;
        sesh->genheader(body, request);

        for (;;) {
            tcp::socket newsocket(ioserv);
            acceptor.accept(newsocket);

            cout << "New Request" << endl;

            sesh->send(newsocket, ioserv, request);
        }
    } catch (exception& e) {
        cerr << e.what() << endl;
    }

    return 0;
}

我已使用 REST 客户端 PAWS 验证是否检索到以下内容：

    POST / HTTP/1.1 
    Host:xx.xx.xx.x:8888
    User-Agent: ProteAuth/1.0 
    Content-Type: application/json; charset=utf-8 
    Content-Type: application/json 
    Accept: */*
    Content-Length: 10
    Connection: close

{"a":"a"}

有谁知道为什么我经常失去与网络的连接（Boost ASIO-embedded http-server）？

Answer 1

我能够确定 async_write 函数 (BOOST::Asio) 和 之间的 JSON 数据传输问题>AFHTTPRequestOperationManager（iOS）。它只是一个格式错误的标头，在 genheader 函数中更新如下：

void Server::genheader(Blob& body, std::string& request)
{
    cout << "Server::genheader" << endl;

    request += "HTTP/1.1 200 OK \r\n";
    request += "Content-Length: ";
    request += std::to_string(body.length());
    request += "\r\n";
    request += "Content-Type: application/json \r\n";
    request += "Connection: Keep-Alive\r\n\r\n";
    request += body;
}