Libcurl获得响应“415不受支持的媒体类型”，但使用curl.exe运行良好

Question

我不确定我做错了什么，但当使用curl中的命令时，不会发生错误。keep change my type tocontent-type:application/x-www-form-urlencoded即使声明了curl_easy_setopt（curl,CURLOPT_HEADER,“content-type：application/json”）；下面是我的代码：

    curl_easy_setopt(curl, CURLOPT_URL, "https://zone1:50000/user/login");
    curl_easy_setopt(curl, CURLOPT_POST, 1);
    curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "cookies.txt");
    const std::string raw_json = R"json({ "username": "admin", "password": "password123"})json";

        Json::CharReaderBuilder builder {};
        auto reader = std::unique_ptr<Json::CharReader>( builder.newCharReader() );
        Json::Value root {};
        std::string errors {};
        const auto is_parsed = reader->parse( raw_json.c_str(),
                                              raw_json.c_str() + raw_json.length(),
                                              &root,
                                              &errors );
        if ( !is_parsed )
        {
            qDebug() << "ERROR: Could not parse! " << errors.c_str();
        }
        Json::FastWriter fastWriter;
        std::string output = fastWriter.write(root);
        qDebug() << "Parsed JSON:" << output.c_str();
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS,output.c_str());
    curl_easy_setopt(curl, CURLOPT_HEADER, "Origin: https://zone1:50000");
    curl_easy_setopt(curl, CURLOPT_ENCODING, "Accept-Encoding: gzip, deflate, br");
    curl_easy_setopt(curl, CURLOPT_HEADER, "Accept-Language: en-US,en;q=0.9");
    curl_easy_setopt(curl, CURLOPT_HEADER, "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36");
    curl_easy_setopt(curl, CURLOPT_HEADER, "Content-Type: application/json");
    curl_easy_setopt(curl, CURLOPT_HEADER, "Accept: application/json, text/plain, */*");
    curl_easy_setopt(curl, CURLOPT_HEADER, "Referer: https://zone1:50000/login");
    curl_easy_setopt(curl, CURLOPT_HEADER, "Connection: keep-alive");
    res = curl_easy_getinfo(curl, CURLINFO_COOKIELIST, cookies);
    res = curl_easy_perform(curl);

成功的curl命令：

curl --cookie cookie.txt -k -g "https://zone1:50000/user/login" -H "Origin: https://zone1:50000" -H "Accept-Encoding: gzip, deflate, br" -H "Accept-Language: en-US,en;q=0.9" -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36" -H "Content-Type: application/json" -H "Accept: application/json, text/plain, */*" -H "Referer: https://zone1:50000/login" -H "Cookie: JSESSIONID=Fn1" -H "Connection: keep-alive" --data-binary "{\"username\":\"admin\",\"password\":\"password\"}"

我收到的答复是：

>

找到主机区域1的包:0x11CE588[串行]

不能复用，即使我们想！

重新使用现有连接！具有主机区域1的(#0)

已连接到zone1(10.1.233.120)端口50000(#0)*>POST/USER/LOGIN HTTP/1.1主机:zone1:50000 Accept:/Accept-Encoding：Accept-Encoding：gzip,deflate,br content-length：44 content-type：application/x-www-form-urlencoded

将包标记为不支持多用途 webserver="" server:webserver

Answer 1

您设置的头都是错误的，CURLOPT_HTTPHEADER的头列表不是一个字符*，它是一种特殊的列表，请尝试

struct curl_slist *list = NULL;
list = curl_slist_append(list, "Accept-Language: en-US,en;q=0.9");
list = curl_slist_append(list, "Content-Type: application/json");
list = curl_slist_append(list, "Accept: application/json, text/plain, */*");
list = curl_slist_append(list, "Referer: https://zone1:50000/login");
list = curl_slist_append(list, "Connection: keep-alive");
curl_easy_setopt(curl, CURLOPT_HEADER, list);
(...)
curl_slist_free_all(list);
(...)

另外，不要使用CURLOPT_HEADER设置user-agent，因为如果将来执行多个请求，或者使用CURLOPT_FOLLOWLOCATION，curl将“忘记”用户代理，而使用CURLOPT_USERAGENT，这样curl就不会忘记它：

curl_easy_setopt(curl, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36");