Building RESTful webservice using qxt

[MichaII]

Hi there,

I want to build a RESTful webservice. I could use some advice on my draft.
I found an example on how to build a soap-webservice here and used the structure of it.

Here's the interface of an resource:

#include <QString>
 
#include <QxtWebServiceDirectory>
#include <QxtWebRequestEvent>
 
class IResource : public QxtWebServiceDirectory
{
    Q_OBJECT
 
public:
    IResource(QString name, QxtAbstractWebSessionManager* sm, QObject* parent = 0):
        QxtWebServiceDirectory(sm, parent),
        name(name)
    {
    }
 
    virtual ~IResource()
    {
    }
 
protected:
   void indexRequested(QxtWebRequestEvent *event)
   {
       if (event->method.compare("GET") == 0)
       {
            doGET(event);
       }
       else if (event->method.compare("PUT") == 0)
       {
            doPUT(event);
       }
       else if (event->method.compare("POST") == 0)
       {
            doPOST(event);
       }
       else if (event->method.compare("DELETE") == 0)
       {
            doDELETE(event);
       }
       else
       {
           // not implemented - status code: 501
       }
   }
 
private:
   void doGET(QxtWebRequestEvent *event)
   {
       // for now just say your name
       postEvent(new QxtWebPageEvent(event->sessionID, event->requestID, name.toAscii()));
   }
 
   void doPUT(QxtWebRequestEvent *event)
   {
   }
 
   void doPOST(QxtWebRequestEvent *event)
   {
   }
 
   void doDELETE(QxtWebRequestEvent *event)
   {
   }
 
   QString name;
};

#include <QString>

#include <QxtWebServiceDirectory>
#include <QxtWebRequestEvent>

class IResource : public QxtWebServiceDirectory
{
    Q_OBJECT

public:
    IResource(QString name, QxtAbstractWebSessionManager* sm, QObject* parent = 0):
        QxtWebServiceDirectory(sm, parent),
        name(name)
    {
    }

    virtual ~IResource()
    {
    }

protected:
   void indexRequested(QxtWebRequestEvent *event)
   {
       if (event->method.compare("GET") == 0)
       {
            doGET(event);
       }
       else if (event->method.compare("PUT") == 0)
       {
            doPUT(event);
       }
       else if (event->method.compare("POST") == 0)
       {
            doPOST(event);
       }
       else if (event->method.compare("DELETE") == 0)
       {
            doDELETE(event);
       }
       else
       {
           // not implemented - status code: 501
       }
   }

private:
   void doGET(QxtWebRequestEvent *event)
   {
       // for now just say your name
       postEvent(new QxtWebPageEvent(event->sessionID, event->requestID, name.toAscii()));
   }

   void doPUT(QxtWebRequestEvent *event)
   {
   }

   void doPOST(QxtWebRequestEvent *event)
   {
   }

   void doDELETE(QxtWebRequestEvent *event)
   {
   }

   QString name;
};

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Each resource should implement the Http-methods (to do something useful)
A session manager or as I called it a "dispatcher" handles the requests (sorry about the naming confusion):

#include <QxtHttpSessionManager>
 
#include "IResource.h"
 
class WebserviceDispatcher : public QxtHttpSessionManager
{
    Q_OBJECT
 
public:
    WebserviceDispatcher(const QHostAddress &host , quint16 port)
    {
        QxtHttpSessionManager(this);
        rootService = new IResource("root", this, this);
        setPort(port);
        setListenInterface(host);
        setConnector(HttpServer);
        setStaticContentService(rootService);
 
        qDebug() << "WebServer Started!";
    }
 
    virtual ~WebserviceDispatcher()
    {
        delete this->rootService;
    }
 
    void addService(QString uri, IResource* newService)
    {
        rootService->addService(uri, newService);
    }
 
protected:
    void incomingRequest(quint32 requestID, const QHttpRequestHeader & header, QxtWebContent *deviceContent)
    {
        QxtHttpSessionManager::incomingRequest(requestID, header, deviceContent);
        qDebug() << "Request: "<< requestID;
        qDebug() << "Method: " << header.method();
        qDebug() << "URI: " << header.path();
    }
 
private:
    IResource* rootService;
};

#include <QxtHttpSessionManager>

#include "IResource.h"

class WebserviceDispatcher : public QxtHttpSessionManager
{
    Q_OBJECT

public:
    WebserviceDispatcher(const QHostAddress &host , quint16 port)
    {
        QxtHttpSessionManager(this);
        rootService = new IResource("root", this, this);
        setPort(port);
        setListenInterface(host);
        setConnector(HttpServer);
        setStaticContentService(rootService);

        qDebug() << "WebServer Started!";
    }

    virtual ~WebserviceDispatcher()
    {
        delete this->rootService;
    }

    void addService(QString uri, IResource* newService)
    {
        rootService->addService(uri, newService);
    }

protected:
    void incomingRequest(quint32 requestID, const QHttpRequestHeader & header, QxtWebContent *deviceContent)
    {
        QxtHttpSessionManager::incomingRequest(requestID, header, deviceContent);
        qDebug() << "Request: "<< requestID;
        qDebug() << "Method: " << header.method();
        qDebug() << "URI: " << header.path();
    }

private:
    IResource* rootService;
};

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finally main looks like this:

#include <QtCore/QCoreApplication>
 
#include "WebserviceDispatcher.h"
#include "IResource.h"
 
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
 
    WebserviceDispatcher* myDispatcher = new WebserviceDispatcher(QHostAddress("localhost"), 8080);
    IResource* service1 = new IResource("service1", myDispatcher, 0);
    IResource* service2 = new IResource("service2", myDispatcher, 0);
    IResource* subService1 = new IResource("subService1", myDispatcher, service1);
    IResource* subService2 = new IResource("subService2", myDispatcher, service2);
 
    service1->addService("sub1", subService1);
    myDispatcher->addService("service1", service1);
 
    service2->addService("sub2", subService2);
    myDispatcher->addService("service2", service2);
 
    myDispatcher->start();
 
    return a.exec();
}

#include <QtCore/QCoreApplication>

#include "WebserviceDispatcher.h"
#include "IResource.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    WebserviceDispatcher* myDispatcher = new WebserviceDispatcher(QHostAddress("localhost"), 8080);
    IResource* service1 = new IResource("service1", myDispatcher, 0);
    IResource* service2 = new IResource("service2", myDispatcher, 0);
    IResource* subService1 = new IResource("subService1", myDispatcher, service1);
    IResource* subService2 = new IResource("subService2", myDispatcher, service2);

    service1->addService("sub1", subService1);
    myDispatcher->addService("service1", service1);

    service2->addService("sub2", subService2);
    myDispatcher->addService("service2", service2);

    myDispatcher->start();

    return a.exec();
}

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this example is working and lets you navigate to the uris:

• http://localhost:8080/
• http://localhost:8080/service1/
• http://localhost:8080/service2/
• http://localhost:8080/service1/sub1/
• http://localhost:8080/service2/sub2/

The service shall provide and accept json objects.
I am not an expert on the topic so any opinion is appreciated (more precisely: is that the intended use of the qxt-classes? Has anyone done that better already and is willing to share ideas?)

Thanks

[yuzhiyuxia]

hi,
why do I not run it well in my computer.I create the project with vs2008 + QT.Now I can't response to the browser.

[rspock]

Ok, well I tried and everything seems ok.

I've a question: how can I use last string in the path as parameters?
For example I'd like to do: http://localhost:8080/service1/sub1/1 where 1 is a parameter to pass to the sub1 not another service to register.

Thanks