Presentation is loading. Please wait.

Presentation is loading. Please wait.

Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 1 Web Services.

Similar presentations


Presentation on theme: "Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 1 Web Services."— Presentation transcript:

1 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 1 Web Services

2 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 2 Contents l Base technologies uXML uSOAP l Web Services l WSDL l UDDI

3 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 3 XML l EXTENSIBLE MARKUP LANGUAGE l Derived from SGML uextremely simple dialect of SGML uMetalanguage uText-based markup language l Designed to describe data uFast becoming standard for data interchange on the web l Standardized uW3C Recommendation, 6 October 2000 : Extensible Markup Language (XML) 1.0 (Second Edition)

4 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 4 XML Example you@yourAddress.com me@myAddress.com......

5 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 5 XML Document Structure l XML and HTML uSimilar syntax but uDesigned for different purposes · HTML : display data · XML : describe data l XML document uContains XML elements l XML element uStart tag (with optional attributes) uContent uEnd Tag l XML tags uNot predefined

6 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 6 XML Syntax l Rules uXML document MUST contain a root element uXML elements MUST be properly nested uAttribute values MUST be quoted uXML tags MUST have a closing tag uXML tags are case sensitive l Well formed XML uXML document without breach of these rules uMore precisely : according to the W3C recommendation

7 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 7 XML Namespaces l Namespace uMethod to avoid element name conflicts · Use of a prefix uUniform Resource Identifier (URI) · Unique name · I.e. Uniform Resource Locator (URL) l xmlns attribute uXMLs way to define namespaces uPlaced in the start tag of an element · All child elements with same prefix are associated with same namespace uSyntax : · General Namespace: · Default Namespace:

8 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 8 XML Validation l Document Type Definition (DTD) or XML-Schema (XSD) uAgreement necessary for data interchange uDifferent ways to define legal building blocks and document structure uExpress shared vocabularies l Valid XML document uWell Formed uConforms to the rules of a DTD or XML-Schema

9 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 9 Document Type Definition (DTD) l Defined as part of the XML specification l Two ways of usage uInternal uExternal l Different Syntax than XML uCant be processed with standard XML Parser l Not hierarchical uCant specify complex relationships uNo context-sensitivity

10 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 10 DTD Example you@yourAddress.com me@myAddress.com...... Internal DOCTYPE declarationExternal DOCTYPE declaration you@yourAddress.com me@myAddress.com......

11 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 11 XML-Schema Definition (XSD) l Written in XML uInherits XMLs Advantages · Simplicity · Extensibility uSpecify any kind of relationship l Support of Data Types uValidation of the corectness of data is easier uFacilitates work with a database uOwn datatypes can be created l Namespaces l Standardized uW3C Recommendation, 2 May 2001

12 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 12 Manipulating XML documents l Tree-based APIs uXML document is mapped in internal tree structure uE.g. DOM (random access mode) · Document Object Model l Event-based APIs uParsing events are reported to application uSAX · Simple API for XML

13 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 13 The benefits of XML l Universal data format l Plain text uFiles can be easily created and edited uPlatform independency uReusability l Hierarchical uFaster access uIncreased efficiency

14 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 14 SOAP l Simple Object Access Protocol uXML-based uIntended for decentralized, distributed environments l Information exchange uHTTP uEnables Remote Procedure Calls (RPCs) using HTTP uEnables document-oriented messaging l Standardized uW3C Recommendation 24 June 2003 : SOAP Version 1.2

15 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 15 SOAP Building Blocks l Required uEnvelope element · Identifies document as a SOAP-message · Framework for packaging message information · http://www.w3.org/2003/05/soap-envelope uBody element · Contains call and response information l Optional uHeader element · Additional application-specific information uFault element · Information about errors that ocurred while processing the message

16 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 16 SOAP Building Blocks Example 1 2 5 6... 7 8 9... 10 11... 12 13 14 specific information about the SOAP message error message from a SOAP message

17 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 17 SOAP HTTP Binding l HTTP Communication uOver TCP/IP uHTTP Client connects to HTTP Server uAfter established connection, client can send HTTP request · HTTP POST or HTTP GET uServer processes request and sends HTTP response back l HTTP POST uContent-Type · MIME Type for the message · Character encoding uContent-Length in bytes POST /item HTTP/1.1 Host: 189.123.345.239 Content-Type: text/plain Content-Length: 200 200 OK Content-Type: text/plain Content-Length: 200 Request Response

18 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 18 Web Service l Service uAbstract set of functionality uProgrammable component · Accessible over the internet through XML messaging l Simplicity and ubiquity uThe Internets success factors uBasic principles of Web Services l Still under development !

19 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 19 Historical context

20 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 20 Web Service Committees l W3C uWorld Wide Web Consortium uhttp://www.w3c.orghttp://www.w3c.org l OASIS uOrganisation for the Advancement of Structured Information Standards uhttp://www.oasis-open.orghttp://www.oasis-open.org l WS-I uWeb Services Interoperability Organisation uhttp://www.ws-i.orghttp://www.ws-i.org l Webservices.org

21 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 21 Web Service Characteristics l Interoperability uPlatform & language independent l Automate processes uProgram to program / business to business (B2B) interaction l Loosely coupled system uMore flexible reconfiguration

22 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 22 Roles

23 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 23 Web Services Architecture l W3C Working Draft 14 May, 2003 : Web Services Architecture uAbstract framework l Programming Stack uConcrete implementation uCollection of standardised protocols and application programming interfaces (APIs) · UDDI : Universal Description, Discovery and Integration Service · WSDL : Web Services Description Language · SOAP : Simple Object Access Protocol · HTTP : Hypertext Transport Protocol

24 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 24

25 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 25 Development l J2EE uIndustry standard uSUN ONE · Java Web Services Developer Pack (JWSDP) uIBM Websphere uetc. l.NET uMircosoft

26 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 26 WSDL l Web Services Description Language l Description of a Web Service uDetails about operations uLocation l Based on XML l Not yet a W3C standard !

27 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 27 WSDL Service definition l Six major elements : u l Example : uhttp://soap.amazon.com/schemas/AmazonWebServices.wsdlhttp://soap.amazon.com/schemas/AmazonWebServices.wsdl

28 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 28 UDDI l Universal Description, Discovery and Integration of Web Services l Specification l Implementation uImplemented on common XML format uProvides Registry uAccess : SOAP l No formal relationship between WSDL and UDDI !

29 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 29 Final Example Dollar Rent-A-Car Southwest Airlines Internet Booking UNIX WINDOWS Web Service Architecture

30 Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 30 Thanks for your attention


Download ppt "Universität Bonn, Seminar Component Engineering for Media Applications SS 2003, Autor – Sebastian Lorenz 1 Web Services."

Similar presentations


Ads by Google