Web Services on AIMS (FAO)

Jeetendra Singh, FAO

http://www.fao.org/aims/

Web Services in

AIMS and Agrovoc work bench

http://aims.fao.org

http://aims.fao.org/



W3C (working group) definition

• A Web Service (also Webservice) is defined by the W3C as "a software system designed to support interoperable machine-to-machine interaction over a network

• Web Services can convert your applications into Web-applications

• Web Services are published, found, and used through the Web



Web services platform elements SOAP (Simple Object Access Protocol)

SOAP is an XML-based protocol to let applications exchange information over HTTP

WSDL (Web Services Description Language) WSDL is an XML-based language for locating and

describing Web services

UDDI (Universal Description, Discovery and Integration) UDDI is a directory service where people can register

and search for Web services



Web Services Architecture



Sending requests,

getting results

Waiting for requests

(known location,known port)

Data in XML format

SOAP-based communication

• SOAP:– Data in a well-defined XML format– Transport over various protocols

• HTTP, SMTP are the most used, perhaps because they are firewall-friendly



XML Messaging Using SOAP



Web Services Stack



A Web Service example in Java

SOAP-awareSOAP-awareServletServlet

(e.g. Apache Axis)(e.g. Apache Axis)

Any classprocessing

the incomingrequests

(“business logic”

Any classprocessing



Any classprocessing



Any classAny classprocessingprocessing

the incomingthe incomingrequestsrequests

(“business logic”(“business logic”

HTTP ServerHTTP Server

Servlet engine (e.g. Apache Tomcat)Servlet engine (e.g. Apache Tomcat)

Sending requests,

getting results

Documents

Web Services on AIMS (FAO)