Web Services Learning (1)

What is Web Services? On the surface, it is an application.ProgramIt provides an API that can be called through the Web. At a deeper level, Web Services is a new application branch. They are self-contained, self-described, and modular applications, it can be described, published, searched, and called on the web.

Protocols used by Web Services:

The Web Services Platform requires a set of protocols to create distributed applications. Any platform has its Data Representation Method and type system. To achieve interoperability, the web services platform must provide a standard type system for communication between different platforms,Programming LanguageAnd different types of systems in the component model. Currently, these protocols include:

1. xml and XSD

Scalable markup language (XML) is the basic format for data representation on the web services platform. In addition to easy resume and ease of analysis, XML has the primary advantage of being independent of any platform.

The Web Services Platform uses XSD as the data type system. To comply with the Web Services standard, all data types used must be converted to the XSD type. To transfer it across different organizations on different platforms and software, you also need to hold it together with something like soap.

2. Soap

Simple Object Access Protocol (SOAP) is a lightweight protocol used to exchange XML encoding information.

3. WSDL

Web Services Description Language is an XML-based language that can be officially described by computers. It is used to describe Web Services and its functions, parameters, and return values.

4. uddl

Uddl aims to establish standards for e-commerce. Uddl is a set of web-based, distributed, provided for Web Services, and implemented standard specifications for the Information Registration Center, it also includes a set of access protocols that enable enterprises to register their own web services so that other enterprises can discover.

5. Call RPC and message transmission in the Remote Process

Web services are actually implementing communication between applications. Now there are two ways for applications to communicate: RPC Remote Procedure Call and message transmission. When RPC is used, the client calls the Remote Process on the server. The common method is to instantiate a remote object and call its methods and attributes.