提升 ASIO HTTP 客户端 POST

Question

I am trying to get boost ASIO library to send a post but the variables never make it to the server. I know the server is working properly (tested with curl)

This code does not work (the variable msg is not posted to the server) but it does work when I use curl

tcp::resolver resolver(io_service);
tcp::resolver::query query("localhost",  "3000"); // "http");
tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
tcp::resolver::iterator end;

tcp::socket socket(io_service);
boost::system::error_code error = boost::asio::error::host_not_found;
while (error && endpoint_iterator != end)
{
  socket.close();
  socket.connect(*endpoint_iterator++, error);
}
if (error)
  throw boost::system::system_error(error);

boost::asio::streambuf request;
std::ostream request_stream(&request);

string sToSend = "msg=testing";

request_stream << "POST / HTTP/1.1\r\n";
request_stream << "Host: " << "localhost:3000" << "\r\n";
request_stream << "Accept: */*\r\n";
request_stream << "Content-Length: " <<  sToSend.length() << "\r\n";
request_stream << "Content-Type: application/x-www-form-urlencoded";
request_stream << "Connection: close\r\n\r\n"; d
request_stream << sToSend;

// Send the request.
boost::asio::write(socket, request);

boost::asio::streambuf response;
boost::asio::read_until(socket, response, "\r\n");

To test the server I use

$ curl --verbose -X POST -d msg=testing123 localhost:3000/
* Hostname was NOT found in DNS cache
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 3000 (#0)
> POST / HTTP/1.1
> User-Agent: curl/7.35.0
> Host: localhost:3000
> Accept: */*
> Content-Length: 14
> Content-Type: application/x-www-form-urlencoded
> 
* upload completely sent off: 14 out of 14 bytes
< HTTP/1.1 200 OK
< X-Powered-By: Express
< Date: Mon, 21 Mar 2016 20:55:00 GMT
< Connection: keep-alive
< Transfer-Encoding: chunked
< 
* Connection #0 to host localhost left intact

Answer 1

您在此行上缺少回车符和换行符：

request_stream << "Content-Type: application/x-www-form-urlencoded";