Web Services The Next Dimension of Enterprise Computing

Web Services The Next Dimension of Enterprise Computing Dr. Billy B. L. Lim School of Information Technology Illinois State University

Outline n Web Services ¡ ¡ ¡ What Why How Who When Not

Questions n Assuming that you’re a venture capitalist: ¡ n Would you fund a company that proposes to build xyz. Books. com and compete directly with the Amazon. com’s of the world? Assuming that you’re a IT 168/177 student: ¡ Would you be able to write an app that gather user addresses and plot a map that shows the route from ISU to the closest address?

E-Commerce Scenarios n n Objective: Capitalize on the success of e-commerce and build a web site to sell books, CDs, and others Scenario 1 ¡ ¡ Build Billy. Books. com and compete directly with the Amazon. com’s of the world Any chance of success here?

E-Commerce Scenarios n Scenario 2 Source: Atkin, J. , “Amazon Everywhere, ” PC Magazine, 9/2003.

What are Web Services? n W 3 C 2003: ¡ “A Web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards. ”

Why Web Services? Observations n “I couldn’t make DCOM work. I tried and failed, again and again. But I can make a Web service in a heartbeat. ” -- Jim Gray, Microsoft Distinguished Engineer (Turing Award (~= Nobel Price for computing) Winner)

Explosive Growth of API Calls / WS n Reference: http: //www. slideshare. net/jmusser/open-apis-state-of-themarket-2011

Why Web Services? Observations n Projected Revenues ¡ 380 millions in 2001 vs. 15. 5 billions in 2005 (Source: Zap. Think, Inc. ’ 02) ¡ IDC estimate: 1. 6 billions in 2004 vs. 34 billions in 2007 (Source: South China Morning Post, May 28, ’ 02)

Why Web Services? Observations n “When do you expect your company to develop a Web Services strategy? ” Source: Info. World Web Services Survey, July ‘ 01

Why Web Services? Observations www. ws-i. org n The industry is aligned … ¡ ¡ Broad industry initiative for Web services n Over 150 industry leaders Interoperability across platforms, applications, and languages

Why Web Services? Observations

Why Web Services? Observations n Technology of the Year (Info. World ’ 02)

Why Web Services? n n Interoperable Easy to use Reusable Ubiquitous

1 st Generation Web Applications UI Logic Biz Logic Browsers OS Services Source: Gusmano ‘ 02 Servers Data, Hosts

2 nd Generation Web Applications Rich Client UI Logic Richer Browsers Biz Logic Tier OS Services Source: Gusmano ‘ 02 Servers Data, Hosts

Next Generation Web Applications Other Services Smarter Clients Applications Become Programmable Web Services XM L XML Standard Browsers HTML Smarter Devices XM L Biz Logic & Tier. Web Logic Service OS OS Services ML X Public Web Services XML Foundation Services XML Internal Web Services XML Open Internet Communications Protocols (HTTP, SMTP, XML, SOAP) Servers Data, Hosts Source: Gusmano ‘ 02

Web Services: Life Cycle Service Registry (e. g. , IBM UDDI service) publish service (e. g. , stock quote) Service Provider (e. g. , Brokerage House) find service bind to service Service Requester (e. g. , XYZ Financial Software) Life Cycle of a Web Service Execution (Registry, Lookup, and Consumption)

What is Under the Hood? n n XML SOAP WSDL UDDI

Web Services: SOAP, WSDL, UDDI

An Overview of SOAP n n Simple Object Access Protocol Lightweight XML-based messaging format Builds on ¡ W 3 C XML standards ¡ IETF HTTP standard Works with: ¡ ¡ ¡ Any operating system Any programming language Any platform

What is a SOAP Message? SOAP Message The complete SOAP Message Protocol Headers Standard Protocol (HTTP, SMTP, etc. ) and SOAP Headers SOAP Envelope <Envelope> encloses payload SOAP Headers SOAP Body Message Name & Data <Header> encloses headers Individual headers <Body> contains SOAP Message Name and Data XML Encoded SOAP Message Name and Data

Simple SOAP Request (Using HTTP) POST /Stock. Quote HTTP/1. 1 Host: www. stockquoteserver. com Content-Type: text/xml Content-Length: 323 SOAPAction: “www. stockquoteserver. com/Get. Last. Trade. Price” <? xml version=“ 1. 0” encoding=“utf-8”? > <SOAP-ENV: Envelope xmlns: SOAP-ENV="http: //schemas. xmlsoap. org/soap/envelope/" SOAP-ENV: encoding. Style="http: //schemas. xmlsoap. org/soap/encoding/"> <SOAP-ENV: Body> <m: Get. Last. Trade. Price xmlns: m="Some-Namespace-URI"> <symbol>DIS</symbol> </m: Get. Last. Trade. Price> </SOAP-ENV: Body> </SOAP-ENV: Envelope>

Simple SOAP Response (Using HTTP) HTTP/1. 1 200 OK Content-Type: text/xml; charset=utf-8 Content-Length: nnnn <? xml version=“ 1. 0” encoding=“utf-8”? > <SOAP-ENV: Envelope xmlns: SOAP-ENV="http: //schemas. xmlsoap. org/soap/envelope/" SOAP-ENV: encoding. Style="http: //schemas. xmlsoap. org/soap/encoding/"> <SOAP-ENV: Body> <m: Get. Last. Trade. Price. Response xmlns: m="Some-Namespace-URI"> <Price>24. 5</Price> </m: Get. Last. Trade. Price. Response> </SOAP-ENV: Body> </SOAP-ENV: Envelope>

WSDL n n Web Services Description Language Lets Web Services describe ¡ ¡ ¡ what they are where they can be found how they should be used

Simplified WSDL example <? xml version="1. 0"? > <service. Description> <soap > <service> <addresses> <address uri="http: //localhost//Hello. World. asmx"/> </addresses> <request. Response name="Hello. World" soap. Action="http: //tempuri. org/Hello. World"> <request ref="s 0: Hello. World"/> <response ref="s 0: Hello. World. Result"/> </request. Response> </service> </soap> </service. Description> Complete one: ISU Hello in Foreign Language Translator

UDDI n n Universal Description, Discovery, and Integration Lets companies find publicly available Web Services on the Internet or corporate Intranets.

UDDI

How useful are Web Services? n Web services: Some possibilities ¡ ¡ ¡ ¡ Financial information (e. g. , stock quotes) Sports information Weather information News Delivery status Tax and shipping calculations Any data that is relevant to the client

Web Services: Who? n Who is doing this? ¡ Vendors n n ¡ Users/Consumers n n n Microsoft, IBM, Sun, Oracle, HP, BEA, etc. . NET passport, Calendar, Alerts, Amazon Web Services, etc. Nordstrom, General Motors, etc. List of public Web Services http: //www. xmethods. net/ Who should pay attention to this? ¡ All of us!

Web Services: When?

Web Services: When? n Web Services will enter most organizations in three distinct phases: [Source: IDC] ¡ 2002 (within the firewall) n n ¡ 2004 (contained external users) n n n ¡ Simplified app integration Increased developer productivity Simplified business-partner connectivity Richer app functionality Subscription-based services 2006 to 2008 (fully dynamic search and use) n n Casual / ad-hoc use of services New business models possible Commoditization of software Pervasive use in nontraditional devices

Web Services: The Not? n Challenges/Issues ¡ ¡ ¡ ¡ Reliability / Consistency Security Authentication Privacy Billing Reuse Performance Incompatible implementations of standards

Web Services: “Lingua Franca” Source: Clarke ‘ 02

References n n n Clarke, N. , “. Net & the J 2 EE: Web Services - Can we live together? , ” Java. One 2002. Gosling, J. , Next-Generation Web Services Conference, Keynote address, Jan, 2002. Gusmano, M. , “Build Web Services with VB. NET, ” Microsoft Internet Developer Group, April 2001.