c++ - POCO : How to upload image to webser using poco in c++

Question

我正在尝试将图像上传到远程网络服务器。我使用过 HTMLForm 和 FilePartSource。我能够成功地将图像上传到本地服务器(即 loclhost)，但是当我尝试将其上传到远程服务器时，从远程 Web 服务器收到的响应是“411 Length Required”。我试图设置 request.setContentLength(sizeofimagefile) 但仍然是同样的问题。任何人都可以指导我解决什么问题或。这是我的代码。

    HTMLForm htmlform;
htmlform.set("aaaaaa", "bbbbbbb");
htmlform.set("cccccc", "ddddddd");
htmlform.setEncoding(HTMLForm::ENCODING_MULTIPART);

PartSource * pFileSrc = new FilePartSource("filename", "application/octet-stream");

std::istream& mystream = pFileSrc->stream();
mystream.seekg(0, std::ios::end);
int uiLength = mystream.tellg();

    htmlform.addPart("file", pFileSrc);

URI uri("yyy");

    HTTPClientSession session(uri.getHost(), uri.getPort());        
HTTPRequest post_req(Poco::Net::HTTPRequest::HTTP_POST,"xxx",HTTPMessage::HTTP_1_1);        
post_req.setKeepAlive(true);
htmlform.prepareSubmit(post_req);


std::ostream& oustr = session.sendRequest(post_req);
htmlform.write(oustr);

HTTPResponse res;
std::istream& rs = session.receiveResponse(res);

std::cerr << rs.rdbuf(); 

提前致谢

Answer 1

std::ostream& oustr = session.sendRequest(post_req);
htmlform.write(oustr);

您的代码无法将表单数据分配给请求对象。所以当你调用 session.sendRequest 时，一个空请求被发送到服务器。要正确地将 HTMLForm 转换为 HTTPRequest，您必须这样写 -

htmlform.write(session.sendRequest(post_req));

对我有用的图片上传代码是-

    HTTPRequest request(HTTPRequest::HTTP_POST, "/fileupload/upload_file.php",    HTTPMessage::HTTP_1_1);
    HTMLForm form;
    form.setEncoding(HTMLForm::ENCODING_MULTIPART);
    form.set("entry1", "value1");
    form.set("entry2", "value2");
    form.addPart("file", new FilePartSource("/home/abc/Pictures/sample.png"));
    form.prepareSubmit(request);

    HTTPClientSession *httpSession = new HTTPClientSession("localhost");
    httpSession->setTimeout(Poco::Timespan(20, 0));
    form.write(httpSession->sendRequest(request));        

    Poco::Net::HTTPResponse res;
    std::istream &is = httpSession->receiveResponse(res);
    Poco::StreamCopier::copyStream(is, std::cout);

对应的上传服务器使用标准的PHP代码上传HTML表单文件。