Vb. NET programming to realize the foundation of Web Service

Web Service is currently a very popular technology in the computer world, so that some people put the Web service into one of the top ten technologies currently. The main content of this article is a brief introduction to the knowledge of Web service and the use of visual Basic. NET implements the specific methods and typical steps of Web services.

Web Service is currently a very popular technology in the computer world, so that some people put the Web service into one of the top ten technologies currently. Indeed, with the wide application and development of the Internet, especially the development of electronic commerce, due to the various complex application systems on the Internet and the requirements for higher security, the emergence of WEB service has satisfied the current requirements and needs, which is explained in detail below. The main content of this article is a brief introduction to the knowledge of Web service and the use of visual Basic. NET implements the specific methods and typical steps of Web services.

What does the Web service do, and why do we need it:

The main function of Web service is to realize the function call of Cross-platform. Also, because of the use of XML in Web service for data exchange, there is no need to worry about firewall impact when using Web service. The Web service is integrated with a variety of features and provides a friendly interface. Therefore, the Web service can realize the reuse of software.

In addition, the invocation of Web service is very simple, in short, calling Web service on the Internet is as simple as invoking a local component, that is, using the HTTP protocol to invoke components on the Internet. As for the specific invocation method, see section fifth of this article, paragraph seventh. So Web service is a component call on the Internet.

Two. Standards and protocols related to Web service:

Web Service is a series of standards and protocols to ensure the dynamic connection between the program and the implementation of its security calls. The main standards and protocols are: XML, WSDL, SOAP, HTTP, UDDI. These standards and protocols are briefly described below.

1. XML is used to exchange data between Xml:web service and WEB service and applications. Web service is based on XML, so that the Web service has the advantages of XML, as well as the disadvantages of XML. One of the most important drawbacks of XML is that the Web service will take up a lot of CPU resources, because the XML data can be used by the system after multi-step processing. So, even if you call a less-functional Web service, you feel slow, so the host requirements for running Web Service are high on the network.

2. http: The application is the HTTP protocol that is invoked to invoke the Web service. So HTTP plays a role as a channel in the Web service invocation process.

3. WSDL:: Is shorthand for Web Service Description language. It is an XML format that describes the Web Service, which instructs the application and the methods that interact with the Web Servie. When you implement some kind of Web services service, you must tell the Web service's interface in order for other programs to invoke it. such as: Service Name, service machine name, listening port number, passing parameter type and so on. WSDL is the standard for Web services descriptions.

4. UDDI: is the abbreviation of Universal Description, Discovery, and integration. Simply put, UDDI is used to centralize and locate WSDL profiles, which play a role as a directory server.

5. SOAP: is the abbreviation for "Simple Object access Protocol", that is, an easy access protocol. SOAP is a message-passing protocol that prescribes how information is passed between Web services.

Three. The environment for the design, commissioning and operation of this article:

(1) Microsoft company Windows 2003 Chinese Enterprise Edition.

(2). Visual Studio. NET 2003 Enterprise build,. NET FrameWork SDK 1.1 version number 4322.

(3). The IIS service starts.