1 / 19

Web Services Overview

Explore the world of web services, including REST and SOAP protocols, XML syntax, HTTP packaging, and various approaches for machine-to-machine communication. Learn about registration, search, resolution, navigation, decomposition, enhancement, and transformation services in the digital library realm.

janetlee
Download Presentation

Web Services Overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Web Services Overview Thomas Hickey

  2. What are Web Services? • Machine-to-machine communication • Run over standard Web protocols • XML syntax, HTTP packaging • Several approaches • REST • Representational State Transfer • SOAP • Simple Object Access Protocol

  3. REST • REST is simplest • Send an HTTP request • Get back a response (XML, HTML) • Examples • Web browser • OpenURL • Z39.50 as a Web service: SRU http://sfx.bath.ac.uk/sfxmenu?genre=book&isbn=1234-5678 http://www.kb.nl/ cgi-zoek/srw.pl?query=test&maxRec=10&recSchema=dc_record

  4. REST: OAI-PMH • Now in version 2.0 • Allows synchronization of databases • Other services can be layered • ODL: Open Digital Libraries • XTCat name authority service

  5. SOAP is more complex • Simple Object Access Protocol • Z39.50 as a SOAP service: SRW • http://www.loc.gov/z3950/agency/zing/srwu/wsdl/zing_srw_binding.wsdl • WSDL • UDDI

  6. Classes of Services • Register • Search • Resolve • Navigate • Decompose • Enhance • Transform

  7. Registration Services • Metadata about metadata • Dublin Core extensions • Digital format descriptions • Metadata about objects • Books • Web resources • Metadata about agents • People • Institutions

  8. Search Services • Go from data to links • Name to preferred form • Search terms to record list

  9. Resolution Services • From links to data • Record numbers to records • Controlled names to name metadata • Class number to textual description

  10. Navigation Services • Movement within hierarchies • Classification, e.g. DDC • FRBR (work, expression, manifestation, item) • General network movement • Link selection and following

  11. Decomposition Services • DDC Numbers • Names within a list • Citations within a paper • Structure of a document • Letters within an image

  12. Enhancement Services • Normalization • Linkage to registered forms • Addition of DDC numbers • Authority control on agents • Content augmentation • Add information to a brief record from a matching longer record

  13. Transformation Services • Syntax translation • MARC21 to MARC XML • Semantic translation • Qualified Dublin Core to MARC21 • Library of Congress SH to FAST • Content translation • English to French?

  14. An Example: ePrints UK • Records harvested from archives • Web services to enhance metadata

  15. Personal e-print archives Institutional e-print archives Non-institutional e-print archives OAI-PMH Subject Classification Service e-Prints UK SOAP Name Authority Service SOAP HTTP Z39.50 RDN Gateway/portal Service Citation Analysis Service RDN Gateway/portal Service RDN Gateway/portal Service

  16. Web Services for ePrints UK • Personal name authorities • Subject classification • Citation analysis

  17. Example: XTCat • Union catalog of thesis and dissertation metadata • Records extracted from WorldCat • Available via OAI-PMH • Separate ‘set’ for electronic theses • We harvest from other repositories • Integrate with existing records • Allow re-harvesting (e.g. by VTLS)

  18. Issues • Syntax • Semantics • Content

  19. No one promised us tomorrow Hawaiian proverb

More Related