QNetworkAccessManager QHttpMultiPart QHttpPart 上传文件 网络模块（二）

一、代码

#ifndef FILEUPLOAD_H
#define FILEUPLOAD_H

#include <QObject>
#include <QHttpMultiPart>
#include <QHttpPart>
#include <QFile>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QUrl>
#include <QMap>
#include <QJsonObject>
#include <QJsonArray>
class FileUpload: public QObject
{
    Q_OBJECT
public:
    FileUpload(QObject *parent = nullptr);
    void setHeader(const QJsonObject &headerobj);
    void upload(const QString &file, const QUrl &url);
private slots:
    void on_finished();
    void on_error(QNetworkReply::NetworkError error);
    void on_redirected(const QUrl &url);
    void on_uploadProgress(qint64 bytesSent, qint64 bytesTotal);
private:
    QJsonObject m_headerobj;
    QNetworkAccessManager m_netMgr;
    QNetworkRequest m_req;
    QNetworkReply *m_pReply;
    QFile *m_pFile;
    QString m_FilePath;
    QUrl m_url;
};

#endif // FILEUPLOAD_H

#include "fileupload.h"

FileUpload::FileUpload(QObject *parent):
    QObject(parent)
{

}

void FileUpload::setHeader(const QJsonObject &headerobj)
{
    m_headerobj = headerobj;
}

void FileUpload::upload(const QString &file, const QUrl &url)
{
    m_FilePath = file;
    m_url = url;
    m_pFile = new QFile;
    m_pFile->setFileName(file);
    if(!m_pFile->open(QIODevice::ReadOnly))
        return;

    QHttpPart FilePart;
    FilePart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"file\"; filename=\"qq.zip\"; "));
    QJsonObject::iterator itor;
    for(itor = m_headerobj.begin();itor != m_headerobj.end();itor++){
        FilePart.setRawHeader(itor.key().toUtf8(),itor.value().toString().toUtf8());
    }
    FilePart.setBodyDevice(m_pFile);

    QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);

    m_pFile->setParent(multiPart);

    multiPart->append(FilePart);

    m_req.setUrl(url);
    m_pReply = m_netMgr.post(m_req,multiPart);
    connect(m_pReply,SIGNAL(finished()),this,SLOT(on_finished()));
    connect(m_pReply,SIGNAL(error(QNetworkReply::NetworkError)),this,SLOT(on_error(QNetworkReply::NetworkError)));
    connect(m_pReply,SIGNAL(redirected(const QUrl)),this,SLOT(on_redirected(const QUrl)));
    connect(m_pReply,SIGNAL(ouploadProgress(qint64 bytesSent, qint64 bytesTotal)),this,SLOT(on_uploadProgress(qint64 bytesSent, qint64 bytesTotal)));

    multiPart->setParent(m_pReply);
}
//******get请求方式
//GET 请求不存在请求实体部分，键值对参数放置在 URL 尾部，因此请求头不需要设置 Content-Type 字段

//******post请求方式
//Content-Type: text/plain  application/json  text/html   可以上传任意格式的文本，比如 text、json、xml、html（中文不进行编码）
//Content-Type: application/x-www-form-urlencoded         将表单内的数据转换拼接成 key-value 对（非 ASCII 码进行编码）
//Content-Type: multipart/form-data                       将表单的数据处理为一条消息，以标签为单元，用分隔符分开。既可以上传键值对，也可以上传文件
void FileUpload::on_finished()
{
    qDebug()<<"FileUpload::on_finished";
}

void FileUpload::on_error(QNetworkReply::NetworkError error)
{
    qDebug()<<"FileUpload::on_error"<<error;
}

void FileUpload::on_redirected(const QUrl &url)
{
    m_pFile->close();
    m_pReply->deleteLater();
    m_pReply->abort();
    m_pReply = nullptr;

    static int count = 0;
    count++;
    if(count < 50){
        upload(m_FilePath,m_url);
    }else{
        count = 0;
    }
}

void FileUpload::on_uploadProgress(qint64 bytesSent, qint64 bytesTotal)
{
    qDebug()<<"FileUpload::on_uploadProgress bytesSent:"<<bytesSent<<" bytesTotal:"<<bytesTotal;
}

二、总结
1.理解MIME类型，理解QHttpMultiPart QHttpPart，明白get post请求Content-Type对应的具体含义
2.理解QNetworkRequest::setRawHeader QHttpPart::setRawHeader的区别
3.QHttpPart::setBody(const QByteArray &body) 适用于较小的数据量传输
4.QHttpPart::setBodyDevice(QIODevice *device) 适用于较大的数据量传输，数据不会立即拷贝