Web services,WSDL,SOAP

Web Service :

• Web services are application components
• Web services communicate using open protocols
• Web services are self-contained and self-describing
• Web services can be discovered using UDDI
• Web services can be used by other applications
• HTTP and XML is the basis for Web services

Web service Life Cycle :

A web service has the below six life-cycle events:

1. Service Provider creates the web service and deploys it.
2. Then service provider, publishes the information about a web service in a service registry.
3. Service consumer search a service registry for available services.
4. Service consumer retrieves the information about the service.
5. Service consumer creates a web service client.
6. Web service client invokes the web service at the location specified in the service description.

NOTE:- Its not mandatory to publish the web service information in a service registry, if the service provider knows the entire list of service consumers. They can directly provide the WSDL URL / file to service consumers.

WSDL :  Web Services Description Language

• WSDL is written in XML
• WSDL is an XML document
• WSDL is used to describe Web services
• WSDL is also used to locate Web services
• WSDL is a W3C recommendation

SOAP :  Simple Object Access Protocol

• SOAP is a communication protocol
• SOAP is for communication between applications
• SOAP is a format for sending messages
• SOAP communicates via Internet
• SOAP is platform independent
• SOAP is language independent
• SOAP is based on XML
• SOAP is simple and extensible
• SOAP allows you to get around firewalls
• SOAP is a W3C recommendation