Introduction to Web Services slide deck conducted as part of training for Java tech track at Virtusa

1. 2000 West Park Drive
Westborough MA 01581 USA
Phone: 508 389 7300 Fax: 508 366 9901
The entire contents of this document are subject to copyright with all rights reserved. All copyrightable text and graphics, the selection, arrangement and presentation of all
information and the overall design of the document are the sole and exclusive property of Virtusa.
Copyright © 2011 Virtusa Corporation. All rights reserved
Web Services

2. 2
Agenda
• What are Web Services?
• SOAP Web Services
• RESTful Web Services
• Service-Oriented Architecture

3. 3
What are Web Services?
• Remote applications need a way to talk to each other
• Applications written on different platforms
• Applications hosted at different locations
• Web Services provide a way for one system to request
data from another system
• Web Services is how different applications ‘talk’ to
each other
• There are 2 main types (currently):
• SOAP Web Services
• RESTful Web Services

4. 4
SOAP Web Services
• SOAP: Simple Object Access Protocol
• Based on XML and XSD definitions
• 3 main components:
• WSDL: Web Service Descriptor Language
• SOAP Envelope
• UDDI: Universal Description, Discovery and Integration

5. 5
SOAP envelope
• This is the payload that is sent to the Web Service from the Client.
• Contains details about which methods to invoke, and with what parameters.
• E.g:
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsd="http:// www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Header> <RequesterCredentials xmlns="urn:ebay:apis:eBLBaseComponents"
soapenv:mustUnderstand="0"> <eBayAuthToken>ABC...123</eBayAuthToken>
<ns:Credentials xmlns:ns="urn:ebay:apis:eBLBaseComponents">
<ns:DevId>someDevId</ns:DevId> <ns:AppId>someAppId</ns:AppId>
<ns:AuthCert>someAuthCert</ns:AuthCert> </ns:Credentials>
</RequesterCredentials> </soapenv:Header>
<soapenv:Body> <GeteBayOfficialTimeRequest
xmlns="urn:ebay:apis:eBLBaseComponents"> <ns1:Version
xmlns:ns1="urn:ebay:apis:eBLBaseComponents">405</ns1:Version>
</GeteBayOfficialTimeRequest>
</soapenv:Body>
</soapenv:Envelope>

6. 6
Web Service Descriptor Language (WSDL)
• Describes what methods are available on the
web service, with what endpoints
• E.g. http://
developer.ebay.com/webservices/latest/ebaySvc.

7. 7
UDDI (Universal Description, Discovery and
Integration)
• A registry which lists down available web
services for Universal Discovery.

8. 8
RESTful web services
• REST: REpresentational State Transfer
• Every resource on the system has a URI
• Details for every resource can be accessed via its
unique URI
• HTTP methods are used to accomplish functions:
• GET – get details
• POST – create new items
• PUT – update items
• DELETE – delete items

9. if ( question != null && question != “” ) {
var answer = ask (question);
if ( answer != satisfactory) {
var betterAnswer = googleIt(question);
}
}
2000 West Park Drive
Westborough MA 01581 USA
Phone: 508 389 7300 Fax: 508 366 9901
The entire contents of this document are subject to copyright with all rights reserved. All copyrightable text and graphics, the selection, arrangement and presentation of all
information and the overall design of the document are the sole and exclusive property of Virtusa.
Copyright © 2011 Virtusa Corporation. All rights reserved
Thank You!

10. www.virtusa.com
© 2011 All rights reserved. Virtusa and all other related logos are either registered trademarks or trademarks of Virtusa Corporation in the United States, the European Union, and/or India. All
other company and service names are the property of their respective holders and may be registered trademarks or trademarks in the United States and/or other countries.