Webservices - in brief

In the following posts, I'm going to show how to consume webservices using Java platform.

First, lets describe what is meant by webservice in brief; it's just a web application, better call it enterprise application, that exposes what is considered as 'web methods' in standard xml descriptor (WSDL for example), utilizing messaging protocol (such as SOAP) over a transport protocol (HTTP), to be consumed in distributed systems.

Example of webservice applications: Web Search, weather reports, stock exchange .. etc.
http://www.amazon.com/gp/browse.html?node=3435361 (Amazon WS)


As defined by w3c: does require an XML-based description mechanism of some kind (such as WSDL) that can be used to describe the service's form and function.

(For more clarification;)
Web services are software components that are developed using specific technologies from three primary technology categories:
- An XML-based description format (for example, WSDL)
- An application messaging protocol (for example, SOAP)
- A collection or transport protocol (for example, HTTP)

Webservice clients then utilizes WSDL file to invoke exposed methods. Clients can be of any platform, written in any language, provided that they agree on messaging & transport protocol that is used in communication. (clients can be web, desktop, mobile application or else).