Qt5模拟curl进行HTTP的head请求， curl -I <url> ：
1 #include <QtCore> 2 #include <QNetworkReply> 3 #include <QNetworkAccessManager> 4 5 int main(int argc, char *argv[]) 6 { 7 QCoreApplication app(argc, argv); 8 9 QUrl url("http://sw.bos.baidu.com/sw-search-sp/software/d4e97ccd4bd9f/jdk-8u144-windows-i586_8.0.1440.1.exe"); 10 auto request = QNetworkRequest(url); 11 //request.setRawHeader("Host", "www.baidu.com"); 12 request.setRawHeader("User-Agent", "curl/7.55.1"); 13 //request.setRawHeader("Accept", "*/*"); 14 //request.setRawHeader("Connection", "keep-alive"); 15 request.setRawHeader("Accept-Encoding", "*"); 16 //qDebug() << request.rawHeaderList(); 17 18 auto manager = new QNetworkAccessManager; 19 manager->head(request); 20 21 QEventLoop loop; 22 QObject::connect(manager, &QNetworkAccessManager::finished, &loop, 23 [&](QNetworkReply* reply) { 24 qDebug() << reply->rawHeaderList(); 25 qDebug() << reply->header(QNetworkRequest::ContentLengthHeader).toInt(); 26 for (auto ele : reply->rawHeaderPairs()) qDebug() << ele.first << ":" << ele.second; 27 reply->deleteLater(); 28 loop.exit(); 29 }); 30 loop.exec(); 31 return 0; 32 }
输出结果：
("Server", "Date", "Content-Type", "Content-Length", "Connection", "ETag", "Last-Modified", "Expires", "Age", "Accept-Ranges", "Content-MD5", "x-bce-debug-id", "x-bce-request-id", "Ohc-Response-Time") 200214072 "Server" : "JSP3/2.0.14" "Date" : "Fri, 13 Oct 2017 07:01:18 GMT" "Content-Type" : "application/octet-stream" "Content-Length" : "200214072" "Connection" : "close" "ETag" : ""8f189a37b323d81c0f0e013cf3070c93"" "Last-Modified" : "Thu, 27 Jul 2017 07:09:28 GMT" "Expires" : "Fri, 13 Oct 2017 07:40:11 GMT" "Age" : "256440" "Accept-Ranges" : "bytes" "Content-MD5" : "jxiaN7Mj2BwPDgE88wcMkw==" "x-bce-debug-id" : "MTAuMTk0LjIzNC40ODpUaHUsIDI3IEp1bCAyMDE3IDE1OjE5OjU2IENTVDoxMTk2OTEwMzI0" "x-bce-request-id" : "9e484498-6dbd-4a98-9bf7-39cb5f47ff7c" "Ohc-Response-Time" : "1 0 0 0 0 0" Press any key to continue . . .
封装成 WebRequest 函数：
1 QString WebRequest(QString url, int& status_code, QString method, 2 QByteArray postData,QList<QNetworkReply::RawHeaderPair>* reply_pairs, int time_out) 3 { 4 QNetworkAccessManager networkManager; 5 QNetworkRequest request; 6 7 request.setUrl(QUrl(url)); 8 request.setHeader(QNetworkRequest::UserAgentHeader, 9 UserAgent); 10 request.setRawHeader("Accept","*/*"); 11 request.setRawHeader("Accept-Encoding", "*"); 12 13 QNetworkReply* reply; 14 if(method == "get") 15 { 16 reply = networkManager.get(request); 17 } 18 else if(method == "post") 19 { 20 request.setHeader(QNetworkRequest::ContentTypeHeader, 21 "application/x-www-form-urlencoded"); 22 reply = networkManager.post(request, postData); 23 } 24 else 25 { 26 qDebug() << "method not support."; 27 return QString(""); 28 } 29 30 QTimer timer; 31 timer.setSingleShot(true); 32 33 QEventLoop loop; 34 QObject::connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit())); 35 QObject::connect(reply, SIGNAL(finished()), &loop, SLOT(quit())); 36 if (time_out <= 0) 37 { 38 time_out = 3000; 39 } 40 timer.start(time_out); // 3 secs. timeout 41 loop.exec(); 42 43 if (timer.isActive()) { 44 timer.stop(); 45 if (reply->error() > 0) { 46 qDebug() << "error";// handle error 47 } 48 else { 49 status_code = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(); 50 if (status_code >= 200 && status_code < 300) 51 { 52 // Success 53 if (reply_pairs) 54 { 55 *reply_pairs = reply->rawHeaderPairs(); 56 } 57 return QString(reply->readAll()); 58 } 59 } 60 } 61 else { 62 // timeout 63 QObject::disconnect(reply, SIGNAL(finished()), &loop, SLOT(quit())); 64 reply->abort(); 65 return QString(""); 66 } 67 }