QHttpMultiPart generates different boundary - spring

Question

When I try to upload files by QHttpMultiPart, there appears a problem. I use the CommonsMultipartResolver.isMultipart() to validate the request, and it returns false.
So I capture frame by Wireshark, and I found an interesting thing: the boundaries in the frame are all different.
Here is my client code
QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
QHttpPart zipPart;
zipPart.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("application/zip"));
zipPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"file\""));
QFile *file = new QFile(pakPath);
file->open(QIODevice::ReadOnly);
zipPart.setBodyDevice(file);
multiPart->append(zipPart);
QNetworkRequest *request = new QNetworkRequest(QUrl(url));
manager->put(*request, multiPart);
And the server code
CommonsMultipartResolver(request.getSession().getServletContext());
if( multipartResolver.isMultipart(request) ) { // here return false
...
I have two questions:
Q1: Is the different boundary make itself be an abnormal in CommonsMultipartResolver?
Q2: Is Different boundary normal or Qt make mistake?

Answer 1

I have a same problem too , my boundary supposed whitout "" ,
I find the source code about QHttpMultiPart class , I found that qt has force set "" by hand . so whatever we set , it will always with "".
qt QHttpMultiPart source code
<pre><code>QNetworkRequest QNetworkAccessManagerPrivate::prepareMultipart(const QNetworkRequest &request, QHttpMultiPart *multiPart)
{
// copy the request, we probably need to add some headers
QNetworkRequest newRequest(request);
// add Content-Type header if not there already
if (!request.header(QNetworkRequest::ContentTypeHeader).isValid()) {
QByteArray contentType;
contentType.reserve(34 + multiPart->d_func()->boundary.count());
contentType += "multipart/";
switch (multiPart->d_func()->contentType) {
case QHttpMultiPart::RelatedType:
contentType += "related";
break;
case QHttpMultiPart::FormDataType:
contentType += "form-data";
break;
case QHttpMultiPart::AlternativeType:
contentType += "alternative";
break;
default:
contentType += "mixed";
break;
}
// putting the boundary into quotes, recommended in RFC 2046 section 5.1.1
contentType += "; boundary=\"" + multiPart->d_func()->boundary + '"';
newRequest.setHeader(QNetworkRequest::ContentTypeHeader, QVariant(contentType));
}
// add MIME-Version header if not there already (we must include the header
// if the message conforms to RFC 2045, see section 4 of that RFC)
QByteArray mimeHeader("MIME-Version");
if (!request.hasRawHeader(mimeHeader))
newRequest.setRawHeader(mimeHeader, QByteArray("1.0"));
QIODevice *device = multiPart->d_func()->device;
if (!device->isReadable()) {
if (!device->isOpen()) {
if (!device->open(QIODevice::ReadOnly))
qWarning("could not open device for reading");
} else {
qWarning("device is not readable");
}
}
return newRequest;
}
</code></pre>
I tried to inherit QHttpMultiPart and rewrite the QNetworkAccessManagerPrivate::prepareMultipart(const QNetworkRequest &request, QHttpMultiPart *multiPart) function , but it seems too bother to do.
finally ， I found a simple way to solve that , it just need to reset boundary paramter agian , that before you post data. it worked. here is my code
<pre><code>
void PeddingBizUI::ossUploadPicture_post(PolicyInfo policy, QString pathName)
{
QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
QHttpPart keyPart;
QString fileName = getFileNameFromPath(pathName);
keyPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-
data; name=\"key\""));
QByteArray ba = QByteArray(QString(policy.dir +
fileName).toStdString().data());
qDebug()<<ba;
keyPart.setBody(ba);
QHttpPart policyPart;
policyPart.setHeader(QNetworkRequest::ContentDispositionHeader,
QVariant("form-data; name=\"policy\""));
policyPart.setBody(policy.policy.toStdString().data());
QHttpPart SignaturePart;
SignaturePart.setHeader(QNetworkRequest::ContentDispositionHeader,
QVariant("form-data; name=\"Signature\""));
SignaturePart.setBody(policy.signature.toStdString().data());
QHttpPart OSSAccessKeyIdPart;
OSSAccessKeyIdPart.setHeader(QNetworkRequest::ContentDispositionHeader,
QVariant("form-data; name=\"OSSAccessKeyId\""));
OSSAccessKeyIdPart.setBody(policy.accessId.toStdString().data());
QHttpPart success_action_statusPart;
success_action_statusPart.setHeader(QNetworkRequest::ContentDispositionHeader,
QVariant("form-data; name=\"success_action_status\""));
success_action_statusPart.setBody(QByteArray::number(200));
QHttpPart aclPart;
aclPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-
data; name=\"x-oss-object-acl\""));
aclPart.setBody("public-read");
QHttpPart imagePart;
QString str = QString("form-data; name=\"file\";
filename=\"%1\"").arg(fileName);
qDebug()<<fileName;
imagePart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant(str));
//不可调换header的先后顺序否则导致
imagePart.setHeader(QNetworkRequest::ContentTypeHeader,
QVariant("image/jpeg")); //请求失败， 提示body data not well formed 失
败
QFile *fileOpen = new QFile(pathName);
fileOpen->open(QIODevice::ReadOnly);
imagePart.setBodyDevice(fileOpen);
fileOpen->setParent(multiPart); // we cannot delete the file now, so delete it
with the multiPart
multiPart->append(keyPart);
multiPart->append(policyPart);
multiPart->append(SignaturePart);
multiPart->append(OSSAccessKeyIdPart);
multiPart->append(success_action_statusPart);
//multiPart->append(aclPart);
multiPart->append(imagePart);
quint32 random[6];
QRandomGenerator::global()->fillRange(random);
QByteArray boundary = "--boundary_zyl_"
+ QByteArray::fromRawData(reinterpret_cast<char *>(random),
sizeof(random)).toBase64();
QUrl url(policy.host);
// QUrl url("http://arithmetic-oss.oss-cn-shenzhen.aliyuncs.com");
QNetworkRequest request(url);
QByteArray contentType;
contentType += "multipart/";
contentType += "form-data";
contentType += "; boundary=";
contentType += boundary;
multiPart->setBoundary(boundary);
request.setHeader(QNetworkRequest::ContentTypeHeader, contentType);
QNetworkReply *reply = m_netUtils.m_manager->post(request, multiPart);
connect(reply, &QNetworkReply::finished, this, [this, multiPart](){
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
qDebug()<<"ossUploadPicture_post response";
onOssUploadPictureResponse(reply);
multiPart->setParent(reply); //内存泄露
reply->deleteLater();
});
// delete the multiPart with the reply
}</code></pre>
and then problem solved.