Implementing a File Transfer Web Service with user authentication (1) (Turn)

Web Author: Cao Www.ASPCool.com time: 2001-11-28 22:49:30 reading times: 754


First, understand the Web Service

Let's start with a simple understanding of web Service.

WEB Services is actually an xml-based system service for businesses and applications. is actually a new concept based on a series of existing technologies. Using it is like using RPC (Remote procedure Call), but the interface it provides is object-based. The biggest feature of it with the original component models, such as Com/dcom,corba,rmi, is the versatility of the Cross-platform (xml-based set of standards), the unobstructed capabilities of HTTP based (across firewalls), and for dot net, with visual The Web service in Studio.NET also features ease of use. Even if the user does not understand the relevant standards, as long as the object-oriented, the Web service has a preliminary understanding of the Web service can be written.

How do I build a Web service? The following technical steps have been widely accepted by industry.

1. The service provider establishes, organizes and publishes network services. Its means are diverse and can be accomplished using programming languages such as delphi,java,c#, middleware, or other special platforms.

2. The service provider uses the WSDL (the Web Services Description Language) to provide a description of the service. A WSDL document provides a service description to a third party.

3. Service Providers Register network services with the UDDI (Universal Description, Discovery, and integration) registry. UDDI enables developers to post services and search for services provided by other people through software. Users will search for a service by searching the UDDI registry.

4. The client application activates the corresponding operation of the network service by binding to the Network service and through SOAP (the simple Object Access Protocol). SOAP provides parameters and return results in XML format and uses HTTP for routing. All network services are communicated through SOAP.

The first step above is the core, which determines the purpose and interface of your Web service. The second step is done automatically in Visual Studio.NET, and you can of course use WSDL.exe to generate it manually. The fourth step provides the greatest convenience for Visual Studio when programming on the client side. As long as the user uses the Add Web service Reference or the Add Web Services Reference (Chinese version) to type the URL, Visual Studio.NET automatically generates the class that invokes the Web service, and the underlying soap is completely transparent to the user.

However, when users need to consider security, they have to consider soap. Remember, security is a must to be considered in the future, in the future, software development becomes configuration integration, software products into services, purchase software into leasing software, most of the services are web-based, you may have to consider who can use your services, who can not use your services, of course, I also prefer open source code and open communication technology, I have also shown my attitude by writing out what I have worked hard to do. But, after all, we still have to rely on writing software to eat:

In Web service, the user name, the password can be transmitted through the SOAP header (SOAP header). In the writing of Web service, SOAP headers need to be processed, but this is not too difficult, and you can see this in the following example and learn how to use it.