a network interface to application functionality, based on standard Internet technologies.
Take a look
A Web service lets you access application functionality over the Internet or just any other network!
As a programmer Web services can be thought of as functions that you can call over the Internet!
we all speak the same language
a Java program can access and use a Web service written in VB.NET and deployed on a Windows server just as easily as a Windows (say C#) program can use a Web service written in Java and running on a Linux Web server.
spell checking, translation , …
stock quotes, currency exchange rates, …
And the list goes on and on!
Web service technology has evolved around a stack of five technologies
Real examples goes across the stack in a top – down approach!
All that for just a RPC
UDDI, WSDL, and SOAP
Nothing really new they are all XML Based
SOAP is Fat, XML-RPC is neat
SOAP Specification is 11,000 words
XML-RPC Specification is 1500 words
XML-RPC has a stable specification, SOAP might undergo some changes
HTTP/1.1 200 OK Connection: close Content-Length: 148 content-Type: text/xml Date: Wed, Jul 28 1999 15:59:04 GMT Server: Sitepoint XML-RPC Server 1.0 <?xml version="1.0"?> <methodResponse> <params> <param> <value><int>42</int></value> </param> </params> </methodResponse>
XML vs. JSON
James Clark (creator of XML) said:
any damn fool could produce a better data format than XML
Douglas Crockford Created JSON
It is easy for humans to read and write.
It is easy for machines to parse and generate.
These properties make JSON an ideal data-interchange language.