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Presented by: Dan Alperovich Patrick Bitonti Eric Breeden

GROUP 1 Presentation Web Services “a major shift in the way we think about software architecture and distributed computing”. Presented by: Dan Alperovich Patrick Bitonti Eric Breeden Brian Pante. Today We Will Cover.

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Presented by: Dan Alperovich Patrick Bitonti Eric Breeden

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  1. GROUP 1 PresentationWeb Services“a major shift in the way we think about softwarearchitecture and distributed computing” Presented by: Dan Alperovich Patrick Bitonti Eric Breeden Brian Pante

  2. Today We Will Cover • Introduction To Web Services • Examples of their Uses • Approach Taken by Businesses with Web Services • Key Features • Technologies Used in Web Services • XML, UDDI, SOAP, WSDL, ebXML • A Simple Code Example to Demonstrate Web Services

  3. Introduction to Web Services • What are Web Services • According to SUN, “a Web service is a modular piece of code on the Internet that provides one or more business functions, and that can be discovered and used on demand.” • Important NEW tool for business-to-business (B2B) collaboration • The Web services approach greatly simplifies B2B collaboration and provides a new model for the way businesses share their data and systems • Get rid of communication problems between businesses by doing everything according to standard request and response protocols • Example of a Web Services Use by a Business • “An enterprise can be the provider of Web services and also the consumer of other Web services. For example, a wholesale distributor of spices could be in the consumer role when it uses a Web service to check on the availability of vanilla beans and in the provider role when it supplies prospective customers with different vendors' prices for vanilla beans.”

  4. Introduction to Web Services • Example of Web Services Uses • “An often-cited example of a Web service is that of a stock quote service, in which the request asks for the current price of a specified stock, and the response gives the stock price. This is one of the simplest forms of a Web service in that the request is filled almost immediately, with the request and response being parts of the same method call.” • “instead of including credit card transaction processing functions in an online retail application, an application can access a Web service that provides those functions”

  5. Web Services Approach • The Web services approach typically involves these actions: • A business first creates and deploys its service. • The business must then register this service over the Internet. This registry contain key information about the service being offered and also shows how additional information can be obtained when necessary. • Other businesses use application programs to search these registries for the services they require. The Web services model supports standard registries such as business registries that conform to UDDI or ebXML. • The information obtained through the UDDI registry allows the other business to locate the server which is running the service and find a service definition that details how to make requests to the service along with a number of other things. The ebXML registry is slightly different in that it involves the exchange of business information between the creator of the Web Service and the user of the Web Service. The two parties concerned then make a business arrangement. The requester then locates and uses the Web service according to the business arrangement.

  6. Web Services Approach • This Model Demonstrates the 5 Key Features of Web Services and may help you to gain a better understanding of the processes involved

  7. Key Features of Web Services • MOST IMPORTANT - Based on Standards • entire Web services approach is based on a set of standard protocols and technologies, so that all participating components understand how to communicate • eliminates confusions that could arise between to business's trying to communicate using two entirely different forms of communication • “For example, service discovery in a UDDI registry, as well as requests for the service, use a standard messaging protocol called SOAP. Service definitions follow a Web service description standard called WSDL. And the transactions that involve the exchange of business profiles follow ebXML Messaging Standards. The bottom line is that companies no longer have to work out special, proprietary agreements regarding how to communicate requests between their systems, and what the communicated information means.” • ELIMINATES STEPS IN COMMUNICATION PROCESS

  8. Key Features of Web Services • Advantages Offered to Providers of Web Services • Provider • Registration Process is simpler then working with each possible client individually • List of Possible Clients is everyone with a Connection to the Internet as opposed to just a few company’s who may have heard about your services •  INCREASED EXPOSURE  INCREASED BUSINESS TRANSACTIONS  INCREASED PROFITS • Can’t argue with something that makes life easier and still allows you to increase productivity

  9. Key Features of Web Services • Advantages Offered to Clients of Web Services • Client • QUICKERand MOREFLEXIBLE application development • no longer a need to develop large applications that include all necessary logic and data when same results are achieved by creating smaller applications that access needed functions through Web services • Clients can search for registered services that meet their requirements, select the best one, and use it. It doesn't matter where the Web service is located on the Internet if it is a registered Web Service then it is available to clients • Entire World Wide Web is available for user to find exactly the service they need for any situation

  10. Web Services Technologies • Good because Web services model is built on standard technologies that are widely accepted, like: • Extensible Markup Language (XML) • Universal Description, Discovery, and Integration (UDDI) • Simple Object Access Protocol (SOAP) • Web Service Description Language (WSDL) • Electronic Business XML (ebXML)

  11. XML • XML is emerging as the standard for exchanging data on the Internet • Why? • XML is relatively easy to learn, especially for people who know HTML • Both come from Std. Generalized Markup Language (SGML) • XML describes the content of a document • An XML tag identifies information in a document, as well as the structure of the information • XML documents have a well-formed structure • each XML tag has an ending tag, and a tag that begins within another tag must end before the end of the other tag, and must be completely nested within that other tag • The structure within an XML tag is consistent • XML is extensible • you can even define your own tags, but must still be well-formed

  12. But how is it used specifically in Web Services? One way is to identify a Web service in a registry so that a program looking for a Web service can easily find it and understand what it does...

  13. UDDI • Definition: UDDI is a cross-industry effort to define business registry standards, including specifications for publishing and discovering information about Web services in a business registry • A UDDI registry is like a "Yellow Pages" for Web services • the Business registry is available to the public for businesses to register their Web services • It provides simple information about: • Who it is (the name of the Web service provider) • What it is (the name of a Web service and, typically, a brief description) • Where it is ("binding templates" that point to an address where the service can be accessed--such as a URL or email address) • How to request it ("tModels" that describe the interface for the Web service-- “technical fingerprint”) • Each registry runs at an “operator” site

  14. You still need some agreed-upon protocol for sending XML documents across the Web so that the receiver understands what it's getting, and what to do in response. That's why there’s…

  15. SOAP • Definition: SOAP is an XML-based protocol for exchanging information in a distributed environment • For example, you register a Web service in a UDDI registry using the SOAP protocol. You also use the SOAP protocol to look for a Web service in a UDDI registry, and once you find the service, you use the SOAP protocol to request it. • More info? Listen to Team3

  16. How does a Web services client know what format to use in making a request to a server? How do the client and the server know what the request means?

  17. WSDL • The answers to these questions are provided by information in an XML document, called the WSDL Document, that contains a description of the Web service's interface and semantics • Definition: WSDL is an XML-based language for describing a Web service. • How it’s used: • The registry entry includes a pointer to a WSDL file that contains the WSDL document for the service. Another business searches the registry and finds the service. A programmer uses the interface and semantic information in the WSDL document to construct the appropriate calls to the service • Here is an example of a WSDL document for a service that provides stock quotes--the application that requests this service supplies a symbol for a specific stock. The service responds with the current price of the stock.

  18. There's no way in SOAP to describe the larger context of the service, or the business process in which the service fits. In the real world, being able to successfully use a Web service might depend on how well the pertinent processes of a requesting business mesh with the processes of a business offering the service, so we have...

  19. ebXML • Definition: ebXML provides a comprehensive B2B framework for describing these processes as well as other information so that businesses can successfully collaborate in a global electronic marketplace • Example (extract taken from one of the ebXML specifications): • The exchange of information between two Parties requires each Party to know the other Party's supported Business Collaborations, the other Party's role in the Business Collaboration, and the technology details about how the other Party sends and receives Messages. • The way each Party can exchange information, in the context of a Business Collaboration, can be described by a Collaboration-Protocol Profile (CPP). The agreement between the parties can be expressed as a Collaboration-Protocol Agreement (CPA).

  20. ebXML use • A high-level view of how these components are used for Web services is as follows: • Parties register their CPPs in an ebXML registry. • A Party (let's call it Party 1) searches the ebXML registry for a needed Web service. It finds that the needed service is provided by Party 2. The information is in Party 2's CPP in the ebXML registry. • Party 2 creates a CPA for a business collaboration with Party 1 and sends the CPA to Party 1. • Party 1 and Party 2 negotiate an agreement. Each stores a copy of the CPA in its server. • Party 1 finds and uses the Web service provided by Party 2 as part of the collaboration defined by the CPA.

  21. An Example of a Web Service • To see the source code for a very simple web service application, go to:http://www2.bc.edu/~pante/MC365/StockQuoteDemo.java • To Run this Example You will Need • J2Me Wireless Toolkit http://java.sun.com/products/j2mewtoolkit/download.html • kSOAP MIDP JAR file and kXML JAR file

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