Poco :: Net :: HTTPClientSession json数据未收到Content-Type

Question

So I am developing a server side Nodejs/expressjs app and a clientside c++/Poco app. I've managed to create a session between where the server is hosted and client. However, any time i try to send my JSON payload, express.js shows req.body as empty.

Google didn't reveal much besides that Content-Type was likely not being transmitted correctly and it appears so. I do set it explicitly but apparently i'm missing a step.

client-side

void upload(std::list<std::string>& args) {
    if (args.size() == 0 || args.front() == "--help") {
        help("upload");
        return;
    }

    std::string repo = args.front();
    args.pop_front();

    std::string name, language;
    auto depends = getDepends(name, language);

    // start making the poco json object here
    Poco::JSON::Object obj;
    obj.set("name", name);
    obj.set("url", repo);

    Poco::URI uri("http://url-of-my-server:50001/make_repo");
    std::string path(uri.getPathAndQuery());


    if (path.empty()) path = "/";

    HTTPClientSession session(uri.getHost(), uri.getPort());
    HTTPRequest request(HTTPRequest::HTTP_POST, path, HTTPMessage::HTTP_1_1);
    HTTPResponse response;

    std::ostream& o = session.sendRequest(request);

    std::cout << response.getStatus() << " " << response.getReason() << std::endl;

    session.setKeepAlive(true);
    request.setContentType("application/json");  // definately set Content-Type right?
    obj.stringify(std::cout);                    // can confirm it is spitting out the valid json here
    obj.stringify(o);                            // place the json in the request stream

    std::istream& s = session.receiveResponse(response);

    // do stuff with returned data
}

server:

var express = require('express');
var app = express();
var bodyParser = require('body-parser');

var database = require('./database.js');  // one of my files
var connection = database.connection;
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());

var port = 50001;   // explicitly set port because environment port kept forcing port 3000

// just a callback to make sure i'm connected to my sql server
connection.query('SELECT 1',function(err, rows) {
    if(err) {
        console.error("Could not connect to the database.");
    } else {
        console.log('connected to database: ' + connection.threadId);
    }

    app.get('/', function(req, res){
        res.send('hello world');
    });

    // this is the route I invoke, (and it is definately invoked)
    app.post('/make_repo', function(req, res, next) {

        console.log(req.headers); // this always returns '{ connection: 'Close', host: 'url-of-my-server:50001' }
        console.log(req.body); // this always returns '{}'

    });

    var listener = app.listen(port, function() {
        console.log("port: " + listener.address().port);
    });

});

It appears that this is on Poco's end because I can transmit test data from postman and it reports just fine. I also setKeepAlive to true on Poco and that appears to be ignored as well. Has anyone used Poco enough to help?

Answer 1

Got a little confused by the stateful stream style of communication. It is http and technically still a stateless connection. All of the information about the request, EXCEPT THE BODY, must be done before you send the initial request.

HTTPClientSession session(uri.getHost(), uri.getPort());
HTTPRequest request(HTTPRequest::HTTP_POST, path, HTTPMessage::HTTP_1_1);
HTTPResponse response;

std::stringstream ss;
obj.stringify(ss);
request.setKeepAlive(true);
request.setContentLength(ss.str().size());
request.setContentType("application/json");  // definately set Content-Type right?

std::ostream& o = session.sendRequest(request);
obj.stringify(o);             // can confirm it is spitting out the valid 

std::cout << response.getStatus() << " " << response.getReason() << std::endl;

Also, needed to set the contentLength which I'd tried before but wasn't working due to the content-type not being sent properly. After the content length and type were set right, the server received correctly without a hitch.