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Web Services Web Services • New set of XML – based protocols that allow internet services to be: – Self Describing • I.e. there is a method to query them about the parameters that are needed to invoke them – Automatically discovered • I.e. there is a way to determine the existence and location of a new service – Able to run over any type of connection to any type of device • Use SOAP to hide network layer, can run over HTTP Example of a Car Web Service • You drive a car from NYC to Boston and want to get a cup of coffee • Coffee sellers: publish/post their services at certain registries using a service description language • You: tell the car to discover the best coffee offering • Car starts purchasing transaction with the seller – invoke the discovered service, put order, pay (credit card) • Get driving instructions and pick up the coffee Purchase Order Example • Old Purchase order (PO) submission process – POs submitted by e-mails – E-mails are manually processed and PO entered into firm’s PO system (format conversion) – Invoices are generated and manually pasted into an e-mail message – Problem: speed, cost, conversion/spelling errors • Web service will automate submission process – – – – PO automatically processed Invoice automatically generated No human in the loop Faster, cheaper, more reliable method What is a Web Service? • Definition: 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 machineprocessable 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. (taken from http://www.w3.org/TR/2003/WD-ws-arch20030808/#whatis) • A new breed of web application. They are self describing, self-contained, modular applications that can be published, located and invoked across the web Key Features of Web Services • Applications published on the Web that perform certain functions, e.g. weather reports, stock quotes, travel package • Other applications discover and invoke them • Are self-contained, self-described and modular: represent black-box functionality – defined by messages service accepts & generates – is independent of underlying implementation • Invoked using standard Internet protocols – E.g., HTTP protocol and XML data format Web Service Models • Partner: serve known customers, partners and remote business units – E.g., Continental lets its customers check flight info and do upgrades remotely. • Private: Integrate software apps within a company developed on different platforms – Build bridges between different apps with Web services front ends; EAI • Public: Offer Web services to the world – Register a service with a broker for consumers to find them, negotiate terms and use them – E.g., get a weather information, buy a product. What is a Web Service? Open Internet Protocols Web Service A programmable application component accessible via standard Internet protocols You can ask a site or device for a description of its Web Services, or use a directory service such as UDDI UDDI Web Services Web Services are defined in terms of the Description Language formats and ordering of messages Web Service consumers can send and receive messages using SOAP All these capabilities are built using open Internet protocols SOAP XML, HTTP Components and Operations Service Broker Publish/ Un-publish Find Service Requestors Bind Web Services Components and Operations Service Providers Building On An XML Foundation Benefits Of XML Foundation User: Beyond browsing – Access and act on information – Greater control, better decision-making, easier collaboration – Optimal support for different devices Business: Integration by design – Best-of-breed internally and externally – Business processes and partners – Agility to run, adapt business better Industry: New opportunities – Don’t have to do it all yourself – Make your value easier to consume – “Plug and play” business relationships SOAP • Simple Object Access Protocol – Allows movement of data defined by XML – Describes a message and how it should be treated – Has rules for relating data in an application to data in a database – Has a framework for developing processes and procedures that can run on one system while calling data from another • http://www.w3c.org/TR/soap UDDI • Use SOAP and XML to define ways for applications to find out about the existence and capabilities of other applications • Should speed up interactions that use SOAP and XML • http://www.uddi.org WSDL • Does for web services what XML does for data – Defines services and describes ways of invoking them – Provides a complete description of a service,its location (i.e., address, port), and a list of operations available. • http://www.w3c.org/TR/wsdl Benefits of Web Services • Business Process Automation • Enterprise Application Integration • Freedom to choose the best technology platform in each situation • Promotes Interoperability • Reduce Complexity through encapsulation • Increases access points • Enable Just in Time integration Web Services Promise… • Ability to distribute applications anywhere on the Web • Services can be changed / updated without touching the calling application • Should dramatically increase ease of implementing B2B applications Issues and Concerns • New and untested technology • XML agreements – Firms have to agree on document descriptions • Transaction management • Security • Quality of Service (QoS) – – – – Reliability Scalability Performance Availability and Accessibility Summary • The Web services framework is being defined, standardized and supported by the industry at a record pace. • Broad industry acceptance and standard compliance will make it ubiquitous. • Will bring an unprecedented level of interoperability to Web applications. • The benefits of Web services, however, are not limited to the Web! Applications • • • • • Real Time Data – News Stock Quotes Internet Telephony Services Instant Messaging CRM Straight Through Processing – Automated end-to-end processing of transactions from trade inception to settlement Creating Web Services • ASP.NET – Easiest way to create web services • SOAP Toolkit V2 (VS6) – MSDN – http://msdn.microsoft.com/webservices/ • SOAP Toolkits for – Apache - http://xml.apache.org/soap/ – XMethods http://www.xmethods.net – …more on google Examples of Web Services today • • • • http://www.amazon.com/webservices http://www.weather.com http://www.google.com http://www.flamenconetworks.com is a firm that creates software for development of web services • MSN network and Verizon Wireless in a joint venture to provide wireless data services http://www.webservices.org/index.php/article/artic leview/408/1/29/ For more information… • http://www.ibm.com/software/webservices • http://java.sun.com/webservices • http://msdn.microsoft.com/webservices/unde rstanding