使用C中的多部分JSON正确格式化

Question

我正在尝试使用C进行邮政请求，因为我需要可执行文件才能在.NET或其他库上不依赖。

执行下面的代码时，服务器都会获得两个预期JSON字符串的零值：

void MakePostReq1(
    const char* verb,
    const char* hostname,
    int port,
    const char* resource,
    const char* opt_urlencoded,
    string& response)
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        cout << "WSAStartup failed.n";
        exit(1);
    }
    SOCKET Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    struct hostent *host;
    host = gethostbyname(hostname);
    SOCKADDR_IN SockAddr;
    SockAddr.sin_port = htons(port);
    SockAddr.sin_family = AF_INET;
    SockAddr.sin_addr.s_addr = *((unsigned long*)host->h_addr);
    cout << "Connecting...n";
    if (connect(Socket, (SOCKADDR*)(&SockAddr), sizeof(SockAddr)) != 0)
    {
        cout << "Could not connect";
        exit(1);
    }
    cout << "Connected.n";
    string json1 = "";
    json1.append("------------------------e661208454117a87");
    json1.append("rn");
    json1.append("Content-Disposition: form-data; name="jsonObject"rn");
    json1.append("Content-Type: application/jsonrn");
    json1.append("rn");
    json1.append("{ jsonObject: "This is a jsonObject" }");
    json1.append("rn");
    json1.append("rn");
    string json2 = "";
    json2.append("------------------------e661208454117a87");
    json2.append("rn");
    json2.append("Content-Disposition: form-data; name="jsonEventObject"rn");
    json2.append("Content-Type: application/jsonrn");
    json2.append("rn");
    json2.append("{ jsonEventObject: "This is a jsonEventObject" }");
    json2.append("rn");
    json2.append("rn");
    string trailer = "";
    trailer.append("------------------------e661208454117a87");
    trailer.append("rn");

    // Build request
    string req = "POST"; // GET | POST
    req.append(" ");
    req.append(resource);
    req.append(" HTTP/1.1rn");
    req.append("Host: ");
    req.append(hostname);
    req.append(":");
    req.append(to_string(port));
    req.append("rn");
    req.append("Cache-Control: no-cachern");
    req.append("Content-length: ");
    char size[5];
    sprintf(size, "%d", json1.size() + json2.size() + trailer.size());
    //sprintf(size, "%d", 319);
    req.append( size );
    req.append("rn");
    req.append("Content-Type: multipart/form-data; boundary="------------------------e661208454117a87"rnrn");
    // add json strings
    req.append(json1);
    req.append(json2);
    req.append(trailer);
    cout << endl;
    cout << "Request size: " << req.size() << endl;
    cout << "Request " << endl << req << endl;
    send(Socket, req.c_str(), req.size(), 0);
    closesocket(Socket);
    WSACleanup();
} 

Answer 1

在这一行：

req.append("Content-Type: multipart/form-data; boundary="------------------------e661208454117a87"rnrn");

从边界上删除引号：

req.append("Content-Type: multipart/form-data; boundary=------------------------e661208454117a87rnrn");

引号被解释为边界的一部分，因此您以下数据边界未识别。