Web Services

The Web Services Description Language (WSDL) is the base for the Web Services specification. Web Services Description Language is an XML based and provide a communication standard for other external system to communicate with webservices. Web Services Description Language Version 2.0 (WSDL 2.0), specification defines the core language which can be used to describe business of web services.

The file extension .wsdl is used in web services. WSDL is used to describe what a service i.e., the operations the service provides, where it resides that is details of the specific protocol address and how to invoke it, that is the details of the data formats and protocols necessary to access the service operation. The difference between UDDI and WSDL is that it is a directory service where businesses can register and search for Web services.

The above architecture consists of messages that are exchanged between the client and server. Web service definitions can be implementated on any language and any platform. We have specify WSDL Document, which contain the following:

• Definition: In WSDL ddocument, definition specify the attibute.
• Types: Type is an element that uses the XML schema language to declare complex data types.
• Messages: Messages are exchanged between the client and the server.
• Binding: It is an element that binds operation elements to a protocol.
• Service: Assigning internet address is the responsibility of the service element.
• Port: Port element associates the binding with the URI for e.g. http://www.indo.com/Home/ where srevices that are run can be accessed.

Interopearbiity: Web Services typically work outside of private networks. It let developers use their preferred programming languages.

Deployability: Web Services are deployed over standard Internet technologies.

Easy to use: WSDL can be used by clients to reduce the amount of code needed to access a service.

• The extra size is really only an issue over low-speed connections or over busy connections.
• When it comes to Web services that uses protocol like http and https is that these protocols are stateless i.e. the interaction between the server and client becomes brief.
• In Web Service Description Language, the WSDL file separates the service documentation from the service itself, and thus creates additional work to discover technical specifications. For example when wsdl code update itself without updating file.