219451, Section 450, 2nd Semester, 2007 219451, Section 450, 2nd Semester, 2007 Web Services Web Services Technology Technology Lect re 4 Lecture 4: Web Service Technology Stack gy and SOAP Monchai Sopitkamon Ph D Monchai Sopitkamon, Ph.D. Outline Outline � Web Services Technology Stack gy � ebXML � SOAP SOAP
Web Services Technology Stack Web Services Technology Stack gy gy � Internet and Web protocols (TCP/IP and HTTP) form the foundational layer for Web services for Web services. � Next layer contains the core XML- processing technologies, including XML and related technologies, e.g., XSL, Vertical Vertical Vertical Vertical Vertical DTDs, and XML Schema. DTDs, and XML Schema. Language Language Language Language Language � Horizontal XML Vocabularies provide functionality that can be used across W eb services Technologies: SOAP, W SDL, UDDI industries, e.g., ebXML. Horizontal XML Vocabularies: ebXML � The technologies that enable Web � The technologies that enable Web services lies above the XML horizontal Core XML Processing: XML, Schema vocabularies. � The top layer contains vertical W eb Framework: Internet Protocols, HTTP, TCP/IP languages XML-based technologies that languages, XML-based technologies that define specific processes for a single industry or group of industries. XML T XML T echnologies that Enable echnologies that Enable B B Business- Business i i -Processing Systems Processing Systems P P i i S S t t � Various XML-based technologies defining business processes can help solve real-world business issues processes can help solve real world business issues. � E.g., when shipping address is not correct, package may be delivered at wrong address or may not be delivered at all. at all. � To prevent this, DTDs and schemas can be used to reduce the amount of errorneous info that enters an organization. o ga at o . � However, only using XML documents does not guarantee that all business partners can understand the same documents. � Business partners must establish sets of standards that every partner uses.
ebXML ebXML � Electronic Business XML is an open, XML-based infrastructure that enables l bal c m anies t c nd ct reliable inter enables global companies to conduct reliable, interoperable e-business erable e b siness � EbXML provides a set of specifications that defines an alternative to Electronic Data Interchange (EDI) systems. � EbXML allows businesses to partner and conduct global B2B transactions EbXML allows businesses to partner and conduct global B2B transactions using XML and the Internet. � Many of these capabilities, although offered by EDI, can be achieved by XML at less costs than through EDI. � With ebXML, organizations exchange business messages, maintain trading W h bXML h b d relationships, define and register business processes and transfer data using a set of specifications that describe the implementation of such systems. � For larger organizations with substantial investments into EDI infrastructure, they can incorporate ebXML into their existing EDI implementation to let them conduct businesses with smaller organizations adopting ebXML technology. p g gy ebXML ebXML Architecture ebXML ebXML Architecture Architecture Architecture Source: http://www.ibm.com/developerworks/xml/library/x-ebxml/
Business Transaction Protocol (BTP) Business Transaction Protocol (BTP) ( ( ) ) Is an XML-based protocol developed to work with existing business-messaging standards, � including ebXML to coordinate and manage complex transactions between business using including ebXML, to coordinate and manage complex transactions between business using Web services or other B2B technology. Members of this technology include BEA Systems, Sun Microsystems, HP , Oracle, Entrust, and � etc. Due to the complexity of processes defined by BTP p y p y , the adoption of the technology has been , p gy � slow. Only a few companies (e.g., BEA and HP) have implemented the protocol in their products and systems. The goal of the protocol is to define how organizations can coordinate their systems to � achieve automated business transactions. BTP describes a transaction as either an atom or a cohesion. BTP d b h h � An atom take part in a two-phase commit transaction – i.e., a process either fully commits to � a transaction or rolls back (cancels) the transaction. An example of an atom includes a single Web services operation and the internal processes � that support the operation that support the operation. Cohesion is a group of atoms that work as a unit to complete a transaction. � With cohesion, certain portions of transactions can be failed without cancelling the � transaction. E E.g., in an on-line order, the credit-card authorization might fail, but the order still can be sent i li d h di d h i i i h f il b h d ill b � to the warehouse to prepare the inventory to ship, and the authorization can be re-tried, instead of forcing the customer to begin the ordering process again. Business Process Modeling Language (BPML) and Business Process Modeling Language (BPML) and B Business Process Query Language (BPQL) Business Process Query Language (BPQL) B i i P P Q Q L L (BPQL) (BPQL) � BPML is a meta-language for modeling business processes processes � BPQL deploys processes. � Companies can use BPML to model, deploy and p , p y manage order, customer-care, demand-planning and product-development processes. � BPML offers a model for businesses to � BPML offers a model for businesses to communicate by exchanging messages. � BPQL employs UDDI to register and discover b business processes deployed on a process d l d repository.
Web Services Flow Language (WSFL) Web Services Flow Language (WSFL) g g g ( g ( ) ) � Is an XML-based language created by IBM to incorporate Web services as part of a business’s workflow businesss workflow � A business workflow is defined as the operations required to accomplish a process or transaction. � In WSFL, Web services providers and Web services consumers can define the work to perform and the flow the work needs to follow to implement business t f d th fl th k d t f ll t i l t b i processes. � WSFL functions as a layer on top of WSDL. � WSFL uses WSDL to describe not only Web services characteristics, but also y Quality of Service (QoS), a characteristic of service not covered by WSDL. � WSFL describes Web services compositions – collections of Web services that work together. � T T wo types of composition models: flow model and global model. wo types of composition models: flow model and global model. � The flow model describes the sequence of steps required by a collection of Web services to accomplish a transaction. � The global model describes an interaction pattern composition, which specifies how the Web services relate to each other not the sequence of interactions how the Web services relate to each other, not the sequence of interactions. Universal Business Language (UBL) Universal Business Language (UBL) g g g ( g ( ) ) � UBL uses ebXML parameters and systems to develop a set of XML business documents develop a set of XML business documents. � Goal: to create a set of international, freely available, unlicensed e-commerce standard documents. � T o achieve this goal, UBL is based on an existing XML technology called the XML Common XML technology called the XML Common Business Language (xCBL) 3.0. � xCBL 3.0 is a freely available widely implemented standard that defines several sets implemented standard that defines several sets of document formats.
History of SOAP History of SOAP y � SOAP was created before the advent of Web services, as a communications protocol that could be used over the Internet. p � When the XML 1.0 was released in 1998, not only did it describe data, but XML could also describe programmatic actions or behaviors. � As a result IBM Lotus Microsoft DevelopMentor and Userland � As a result, IBM, Lotus, Microsoft, DevelopMentor and Userland Software began collaborating to develop an XML-messaging protocol to define a non-platform specific way to invoke remote operations. � This work later turned into the development of SOAP. � The first SOAP specification, SOAP 0.9, was published in 1999. � Several subsequent versions of SOAP were followed before the protocol was submitted to the W3C protocol was submitted to the W3C. � The W3C released SOAP 1.2 as a Working Draft in July 2001. � On June 24, 2003, SOAP 1.2 was finalized and accepted as part of the W3C Recommendations. SOAP Architecture SOAP Architecture � Web services are often part of larger, object-based architectures h � Good systems architectures promote loosely-coupled systems – i.e., systems in which each software component’s implementation is independent of those surrounding it. i l i i i d d f h di i � When an application resides in a loosely-coupled system, changes to one component or application do not affect other applications in the system. li ti i th t � E.g., if the Web service implementation is modified to enhance performance, the developer does not have to modify other applications in the system applications in the system. � Advantage: a developer can change a particular component without going through the error-prone process of modifying other system components ใ other system components ใ
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