CORS跨域限制以及预请求验证（C++ Qt框架实现）

目录

 

理论

演示及代码

---

理论

跨域默认情况下允许方法：GET、HEAD、POST

默认情况下允许的Content-Type：text/plain、multipart/form-data、application/x-www-form-urlencoded

如果要使用用户自定义头，要在被请求的服务器HTTP响应消息中加入：

Access-Control-Allow-Headers: X-Test-Cors

这个X-Test-Cors就是自定义消息头

如果要添加新的跨域方法要添加如下消息：

Access-COntrol-Allow-Methods: PUT, Delete

如果要设置Option这个预请求时间，则要加如下消息头：

Access-Control-Max-Age: 1000

 

演示及代码

现在有2个页面，都在127.0.0.1的机器上，

一个服务是80端口，一个服务是81端口，

80端口通过JavaScript获取81端口跨域服务！

现在使用自定义消息头！

程序运行截图如下：

此时在81上添加允许X-Test-Cors的响应消息：

运行这个时候就没有报错了，并且浏览器有预处理和响应了！

看下这Option预处理头和Post请求：

这里通过设置Max-Age设置预处理头：

运行截图如下：

程序结构如下：

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include 

QT_BEGIN_NAMESPACE
class QTcpServer;
class QTcpSocket;
QT_END_NAMESPACE

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

protected slots:
    void newConnectionSlot80();
    void newConnectionSlot81();

    void errorStringSlot80();
    void errorStringSlot81();

    void sendMsg80();
    void sendMsg81();

private:
    Ui::Widget *ui;

    QTcpServer *m_tcpServer80;
    QTcpSocket *m_tcpSocket80;

    QTcpServer *m_tcpServer81;
    QTcpSocket *m_tcpSocket81;
};

#endif // WIDGET_H

main.cpp

#include "widget.h"
#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();

    return a.exec();
}

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include 
#include 
#include 

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);

    m_tcpServer80 = new QTcpServer(this);
    m_tcpServer80->listen(QHostAddress::Any, 80);
    m_tcpServer81 = new QTcpServer(this);
    m_tcpServer81->listen(QHostAddress::Any, 81);

    connect(m_tcpServer80, SIGNAL(newConnection()), this, SLOT(newConnectionSlot80()));
    connect(m_tcpServer81, SIGNAL(newConnection()), this, SLOT(newConnectionSlot81()));

    connect(m_tcpServer80, SIGNAL(acceptError(QAbstractSocket::SocketError)), this, SLOT(errorStringSlot80()));
    connect(m_tcpServer81, SIGNAL(acceptError(QAbstractSocket::SocketError)), this, SLOT(errorStringSlot81()));


}

Widget::~Widget()
{
    delete ui;
    m_tcpServer80->close();
    m_tcpServer81->close();
}

void Widget::newConnectionSlot80()
{
    qDebug() << "newConnectionSlot80() called";
    m_tcpSocket80 = m_tcpServer80->nextPendingConnection();
    connect(m_tcpSocket80, SIGNAL(readyRead()), this, SLOT(sendMsg80()));
}

void Widget::newConnectionSlot81()
{
    qDebug() << "newConnectionSlot81() called";
    m_tcpSocket81 = m_tcpServer81->nextPendingConnection();
    connect(m_tcpSocket81, SIGNAL(readyRead()), this, SLOT(sendMsg81()));
}

void Widget::errorStringSlot80()
{
    qDebug() << m_tcpServer80->errorString();
}

void Widget::errorStringSlot81()
{
    qDebug() << m_tcpServer81->errorString();
}

void Widget::sendMsg80()
{
//    QString contentStr = ""
//                             ""
//                             ""
//                             ""
//                             ""
//                             "
Socket 80
"
//                             ""
//                             ""
//                             "";

        QString contentStr = ""
                                 ""
                                 ""
                                 ""
                                 ""
                                 "
Socket 80
"
                                 ""
                                 ""
                                 "";

        //send msg
        QString str = "HTTP/1.1 200 OK\r\n";
        str.append("Server:nginx\r\n");
        str.append("Content-Type:text/html\r\n");
        str.append("Connection:keep-alive\r\n");
        str.append(QString("Content-Length:%1\r\n\r\n").arg(contentStr.size()));
        str.append(contentStr);
        qDebug() << str;
        m_tcpSocket80->write(str.toStdString().c_str());
}

void Widget::sendMsg81()
{
    QString contentStr = ""
                         ""
                         ""
                         ""
                         ""
                         "
Socket 81
"
                         ""
                         "";

    //send msg
    QString str = "HTTP/1.1 200 OK\r\n";
    str.append("Server:nginx\r\n");
    str.append("Content-Type:text/html\r\n");
    str.append("Connection:keep-alive\r\n");
    str.append("Access-Control-Allow-Origin: *\r\n");
    str.append("Access-Control-Allow-Headers: X-Test-Cors\r\n");
    str.append("Access-Control-Max-Age: 1000\r\n");
    str.append(QString("Content-Length:%1\r\n\r\n").arg(contentStr.size()));
    str.append(contentStr);
    qDebug() << str;
    m_tcpSocket81->write(str.toStdString().c_str());
}

 

程序打包下载：

https://github.com/fengfanchen/Qt/tree/master/HTTPCORSTest