Symbian学习笔记8 之 初探WebServices API的使用(上)

?(转载 --留着以后学习)

从SDK文档中提供的资料来看这个接口似乎有点复杂，包括了Connection API、Description API和Manager API三套东西，此外还涉到了XML的解析之类的一些API的应用。阅读了一下它的例子程序（S60Ex目录下的AddressBook），让我更晕乎了。怎么跟自己平时使用的WebService不一样了？在SDK文档中关于CSenServiceConnection有这么一段描述：Web Services包括两种不同的框架模型: 1. Identity Based Web Services Framework (ID-WSF). The framework ID for this is KDefaultIdWsfFrameworkID??("ID-WSF"). 2. Basic Web Services Framework. Framework ID is KDefaultBasicWebServicesFrameworkID ("WS-I").如果提供了Contract则缺省使用ID-WSF。首先用.NET做一个简单的WebServices来测试，就用缺省产生的HelloWorld吧。很简单的，它的SOAP描述如下：view plaincopy to clipboardprint?<PRE class=csharp name="code">POST /uim/PService.asmx HTTP/1.1? ???Host: localhost? ? Content-Type: text/xml; charset=utf-8? ???Content-Length: length? ???SOAPAction: "urn:pservice:helloworld"? ?<?xml version="1.0" encoding="utf-8"?>? ? <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">? ? <soap:Body>? ? <HelloWorld xmlns="http://sharetop/pservice" />? ? </soap:Body>? ? </soap:Envelope>? ? HTTP/1.1 200 OK? ???Content-Type: text/xml; charset=utf-8? ???Content-Length: length? ???<?xml version="1.0" encoding="utf-8"?>? ? <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">? ? ??<soap:Body>? ? <HelloWorldResponse xmlns="http://sharetop/pservice">? ? <HelloWorldResult>string</HelloWorldResult>? ???</HelloWorldResponse>? ? ??</soap:Body>? ? </soap:Envelope></PRE>??view plaincopy to clipboardprint?POST /uim/PService.asmx HTTP/1.1? ???Host: localhostContent-Type: text/xml; charset=utf-8? ???Content-Length: length? ???SOAPAction: "urn:pservice:helloworld"? ?<?xml version="1.0" encoding="utf-8"?>? ? <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">? ???<soap:Body>? ???<HelloWorld xmlns="http://sharetop/pservice" />? ???</soap:Body>? ???</soap:Envelope>? ???HTTP/1.1 200 OK? ???Content-Type: text/xml; charset=utf-8? ???Content-Length: length? ? <?xml version="1.0" encoding="utf-8"?>? ???<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">? ?????<soap:Body>? ???<HelloWorldResponse xmlns="http://sharetop/pservice">? ???<HelloWorldResult>string</HelloWorldResult>? ???</HelloWorldResponse>? ???</soap:Body>? ?</soap:Envelope>??POST /uim/PService.asmx HTTP/1.1Host: localhostContent-Type: text/xml; charset=utf-8Content-Length: lengthSOAPAction: "urn:pservice:helloworld"<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">??<soap:Body>? ? <HelloWorld xmlns="http://sharetop/pservice" />??</soap:Body></soap:Envelope>HTTP/1.1 200 OKContent-Type: text/xml; charset=utf-8Content-Length: length<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">??<soap:Body>? ? <HelloWorldResponse xmlns="http://sharetop/pservice">? ?? ?<HelloWorldResult>string</HelloWorldResult>? ? </HelloWorldResponse>??</soap:Body></soap:Envelope>下面我们自己来做一个WS的客户端实例吧。先用向导生成一个HelloWorld应用，为了研究方便，我们不打算做什么界面，所有的输出都通过LOG输出到日志文件。为了编码方便，我们增加一个类WebEngine，它应该派生于CSenBaseFragment和MSenServiceConsumer。声明如下： view plaincopy to clipboardprint?class CWebEngine : public CSenBaseFragment,public MSenServiceConsumer? ???{? ???public:? ???~CWebEngine();? ???static CWebEngine* NewL();? ?????static CWebEngine* NewLC();? ???void ConnectL();? ? void SayHello();? ???? ?//from MSenServiceConsumer? ???virtual void HandleMessageL(const TDesC8& aMessage);? ?? ?virtual void HandleErrorL(const TInt aErrorCode,const TDesC8& aError);? ? ??virtual void SetStatus(const TInt aStatus);? ???protected:? ???//from CSenBaseFragment? ?virtual void StartElementL(const TDesC8& aNsUri,const TDesC8& aLocalName,const TDesC8& aQName,const Xml::RAttributeArray& aAttrs);????virtual void EndElementL(const TDesC8& aNsUri,??const TDesC8& aLocalName,const TDesC8& aQName);? ?private:? ?CWebEngine();? ?void ConstructL();? ???public:? ?CHelloWorldResult * delegate;? ? private:? ?????CSenServiceConnection* iConnection;? ? CSenXmlServiceDescription* iSession;? ???CSenXmlReader* iXmlReader;? ???};??class CWebEngine : public CSenBaseFragment,public MSenServiceConsumer{public:? ? ? ? ~CWebEngine();? ? ? ? static CWebEngine* NewL();? ? ? ? static CWebEngine* NewLC();? ? ? ? void ConnectL();? ? ? ? void SayHello();? ? ? ? //from MSenServiceConsumer? ? ? ? virtual void HandleMessageL(const TDesC8& aMessage);? ? ? ? virtual void HandleErrorL(const TInt aErrorCode,const TDesC8& aError);? ? ? ? virtual void SetStatus(const TInt aStatus);protected:? ? ? ? //from CSenBaseFragment? ? ? ? virtual void StartElementL(const TDesC8& aNsUri,const Xml::RAttributeArray& aAttrs);? ? ? ? ? ? ? ?? ? ? ? ? ? virtual void EndElementL(const TDesC8& aNsUri,const TDesC8& aQName);private:? ? ? ? CWebEngine();? ? ? ? void ConstructL();public:? ? ? ? CHelloWorldResult * delegate;private:? ? ? ? CSenServiceConnection* iConnection;? ? ? ? CSenXmlServiceDescription* iSession;? ? ? ? ? ? ? ? CSenXmlReader* iXmlReader;};除了实现两个父类的方法以外，还要增加ConnectL()用来连接，SayHello()用来调用远程方法。那个delegate是一个 CHelloWorldResult类的实例，这个类同样派生于CSenDomFragment，说明它对应一段XML内容，我们用它来处理结果，就是那个HelloWorldResponse标签下的内容。这个WebEngine的实现逻辑是：先在ConnectL中初始化WS客户端，在SetStatus回调中取当前状态值如果为 KSenConnectionStatusReady ，则可以调用SayHello去执行那个WS的方法，然后，在HandleMessageL回调中将得到的结果（XML内容的字节流）去解析一下，解析 XML的回调就是那两个StartElement和EndElement。