August 10, 2009
What is web Service?
The web service is a web API. The ￢ﾀﾜWeb Services￢ﾀ? is an effort to build a distributed computing platform for the web.
The basic standards for web services are:
ￂﾧ XML (Extensible Markup Language)
ￂﾧ SOAP (Simple Object Access Protocol)
ￂﾧ WSDL (Web Services Description Language)
ￂﾧ UDDI (Universal Description, Discovery and Integration)
ￂﾧ All Web Services documents are written in XML
ￂﾧ XML Schema are used to define the elements used in Web Services communication
Schema: A schema is the definition of each of the tags within a xml document.
ￂﾧ SOAP is used to communicate with the Web Service
ￂﾧ Both the request and the response are SOAP messages
ￂﾧ The body of the message is contained within a SOAP ￢ﾀﾜenvelope￢ﾀ?
ￂﾧ ￢ﾀﾜBinds￢ﾀ? the client to the web service
ￂﾧ Describes the Web Service and defines the functions that are exposed in the Web Service
ￂﾧ Defines the XML grammar to be used in the messages
o Uses the W3C Schema language
ￂﾧ UDDI is used to register and look up services with a central registry
ￂﾧ Service Providers can publish information about their business and the services
ￂﾧ Service consumers can look up services that are available by
o Service category
o Specific service
Web services are a set of tools that can be used in a number of ways.
The three most common styles of use are RPC, SOA and REST.
ￂﾧ Remote procedure calls
ￂﾧ Service-oriented architecture
ￂﾧ Representational state transfer