Maandag 24 november 2003

1
CoFfTeA seminarie

• Maandag 24 november 2003

2
Agenda (1)

• Welkom Chris Van Keer (departementsbestuur)
• Inleiding Patrick De Causmaecker
• Achtergrond Peter Demeester
• Raamwerk
• Ontologie
• Webgebaseerde datarepresentatietalen
• Gebruikte tools Peter Demeester Nele Custers
• OilEd
• WordNet
• JDom

• Jena
• D2RMap
• OpenTS

3
Agenda (2)

• Koffie
• Demonstratie
• Discussie
• Drink

4
Inleiding

• CoFfTeA

5
Goals

• Offer software developers better insight in
• needs of planning practice
• the opportunities of component based software
  development
• How software can function with loosely connected
  components
• A component model for timetabling

6
Further expectations

• Semantic Web Technology
• Suggested by members of the user committee
• Offers semantics, representation formats,
  connectivity, interoperability, logic,
• Can it support a development strategy?

7
An example domain

• Timetabling
• Group has experience
• PATAT, Nurse Rostering, TITAN
• Links with the user committee
• Planning, scheduling, rostering
• Build a component framework for timetabling
  using concepts and tools taken from the semantic
  web context

8
Questions to answer or not

• What is a framework?
• How to build a framework?
• What is timetabling?
• How to incorporate users desires?
• How to understand the user?
• How to explain the results?

9
Questions to answer

• What does the semantic web to help?
• What is ontology?
• How can ontology speed up development?
• How can existing tools be used?

10
Realisations

• We developed
• An ontology for timetabling.
• A mapping tool for timetabling applications using
  this ontology
• A constraint editor that can use our numbering
  techniques developed elsewhere to allow the
  definition of constraints using the ontology and
  the results of the mapping
• An application framework that is consistent with
  the ontology and that allows access to the OpenTS
  metaheuristics framework for optimisation of
  timetables.

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Achtergrond

• Raamwerk, ontologie en webgebaseerde
  datarepresentatietalen

12
Local search component
OpenTS
evaluation component
constraint component
Query model in RDQL and Jena API
Constraints in XML, generated by the GSCG Jena,
JDom, OilEd source, ..
XML D2R mapping file
(semi)-automatic generation of the D2R mapping
file
JWNL, WordNet, ontology for timetabling, OilEd
source, Jena, JDom,
Semantic mapping component
school database
13
Raamwerk
14
Why Component Framework

• Conventional software reuse
• Copy paste and OO class inheritance
• Details about implementation are needed (-)
• Reusable components
• Provide software reuse
• Implementation details are not needed ()
• Software development
• Software components as building blocks to develop
  applications
• Software maintenance
• interchangeable components
• Easier, quicker, cheaper development and
  maintenance ()

15
What Is a Component Framework

• One preferred definition
• A component framework is a collection of
  collaborating components designed for reuse in
  one or more problem domains
• Component framework and class library
• In OO context, a component framework is often a
  class library
• But a component framework is more than a class
  library target problem domain, between
  programming language toolkit and application

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Criteria for Good Components

• Reusable content generic
• Well-encapsulated black-box components are
  desired
• Well-defined interfaces
• What arguments need a method and what will be the
  result?
• Ease of reuse e.g. composable
• Independently deployed

17
Criteria for Good Component Frameworks

• Good individual components not sufficient
• Good architecture framework architecture affects
  the application architecture
• Ease of learning and use
• well-organised layered, categorized
• for framework developers to handle complexity of
  framework
• for framework users easy to find what they need
• consistency between components
• following conventions in implementation how they
  expect and return info, handle errors, affect
  environment, and so on
• naming strategy
• name of classes for domain entities same as
  domain terms
• name of method reflecting function services (ex.
  Getters and setters methods)

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Problem Domain, Application and Framework

• Application

Framework
Problem Domain
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Component Models

• Sun J2EE
• language-specific (Java) and platform-independent
• Microsoft .NET
• Multi-language (but no support yet for Java) and
  platform-specific (Windows, not really)

20
Ontologie
21
Pieter Brueghel, de oude de toren van Babel
(1563)
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What is an ontology?

• An ontology defines a common vocabulary for
  researchers who need to share information in a
  domain. It includes machine-interpretable
  definitions of basic concepts in the domain and
  relations among them

23
What is an ontology?

• Ontology (following the Oxford English
  Dictionary) the science or study of being
• In other words Theory about the nature of
  existence, of what types of things exist
• The term ontology was introduced by philosophy
  but AI and Web researchers have co-opted the term
  for their own jargon
• Next examples come from John F Sowa
  http//www.jfsowa.com/ontology/ontoshar.htm

24
Aristotle's categories
25
Tree of Porphyry
26
What is an ontology?

• No universally agreed meaning for the term
• Possible definition Uschold
• Conceptualisation a world view a way of
  thinking about a domain. Set of informal rules
  that constrain the structure of a piece of
  reality.Typically expressed as a set of
  concepts (entities, attributes, processes), their
  definitions and their inter-relationships.
• Implicit in someones head
• Explicit this is called an ontology

27
What is an ontology?

• Ontology is an explicit account or representation
  of some part of a conceptualisation
• Variety of forms necessarily it will include a
  vocabulary of terms and some specification of
  their meaning
• Manifestation of a shared understanding of a
  domain that is agreed between a number of parties.

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Kinds of ontologies

• Formality degree of formality by which a
  vocabulary is created and meaning is specified
• Purpose intended uses of the ontology
• Subject matter nature of subject matter that the
  ontology is characterising

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Formality
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Purpose (1)

• Communication between people unambiguous (maybe
  informal) definition
• Inter-operability among systems achieved by
  translating between different
• modelling methods
• paradigms
• languages
• software tools

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Communication between people
32
Purpose (Inter-operability)
L1
L2
L1
L2
T2
T1
interlingua
T3
T4
L4
L3
L4
L3
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Purpose (2)

• Systems engineering benefits
• Reusability ontology basis for formal encoding
  of entities, attributes, processes and their
  inter-relationships in the domain of interest.
  This may become a reusable/shared component
• Knowledge acquisition increase speed
  reliability by using an existing ontology as
  basis for guiding knowledge acquisition

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Purpose (3)

• Systems engineering benefits
• Reliability formal representation makes possible
  the automation of consistency checking.
• Specification ontology can assist in the process
  of
• identifying requirements of the system
• understanding the relationships among the
  components of the system
• and provides a declarative specification of a
  software system

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Purpose (4)
COMMUNICATION Between people organisations
INTER-OPERABILITY between systems
Reusable components
Reliability Specification SYSTEMS
ENGINEERING
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Genericity (related with purpose)

• Extent to which an ontology can/is intended to be
  reused in a range of different situations

Upper-level models
Application ontologies
37
Subject matter

• Most common categories
• Domain ontology (medicine, geology, finance,)
• Task, method or problem solving ontology
• Representation or meta-ontology

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What is in an ontology?

• An ontology is a formal explicit description of
• concepts in a domain of discourse (classes),
• properties of each concept describing various
  features,
• attributes of the concepts (slots or roles or
  properties),
• and restrictions on slots (facets or role
  restrictions)
• An ontology together with a set of individual
  instances of classes constitutes a knowledge base.

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What is in an ontology?

• Classes are the focus of most ontologies
• Classes describes concepts in the domain
• Ex class of beers represents all beersspecific
  beers are instances of this class
• A class can have subclasses that represent
  concepts that are more specific than the
  superclass
• Ex you can divide the class of all beers into
  dark, yellow, amber,Alternatively we can divide
  the class into pils, kriek, trappist,

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What is in an ontology?

• Slots describe properties of classes and
  instances Kriek Lindemans is produced by the
  brewery Lindemans
• In practical terms, developing an ontology
  includes
• Defining classes in the ontology
• Arranging the classes in a taxonomic
  (subclass-superclass) hierarchy
• Defining slots and describing allowed values for
  these slots
• Filling in the values for slots for instances

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Webgebaseerde datarepresentatietalen
42
Problem with current web

• Designed to improve the exchange of information
  between different people
• Majority of data on the web today is that the
  form it is published in (HTML) is difficult to
  use on a large scale
• Machines/software programs/agents have trouble
  processing this information
• Need of languages that allow automatic
  interpretation of content

43
What is the Semantic Web?

• Goal of the SW make info on the web
  machine-processable
• Think of it as being an efficient way of
  representing data on the WWW (or as a globally
  linked database)
• Semantic Web is invented by Tim Berners-Lee
• On a XML conference (XML 2000) in December 2000 T
  B-L introduced an architecture for the Semantic
  Web

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Architecture of the SW
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First layer URI

• items on the web are identified through the use
  of identifiers
• Since each item is considered a resource
  identifiers are called Uniform Resource
  Identifiers
• URI can be given to anything
• Anything that has a URI can be said to be on the
  web
• URI is the foundation of the web
• Best known URI is the URL

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Second layer XML

• XML acronym for eXtensible Markup Language
• Pro Users can create documents using their own
  structure and syntax.
• XML allows to invent tags suitable for a
  particular problem
• In HTML number of tags is limited

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XML an example

• lt?xml version"1.0"?gt
• ltarticlegt
• lttitlegtUsing web standards for
  timetablinglt/titlegt
• ltauthorgtSep Ducamaerckelt/authorgt
• ltauthorgtPer Tedesemlt/authorgt
• ltauthorgtVenghed Bangerlt/authorgt
• ltaffiliationgtKaHo Sint-Lieven,Gentlt/affiliationgt
• lt/articlegt

48
The need of a schema language

• The freedom of inventing tags can lead to
  confusion
• Schemas determine how content should be formatted
• XML Schema tells something about syntax
• Pro exchange syntactically valid XML documents
  between people, organisations,

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Example of an XML Schema

• lt?xml version"1.0""?gt
• ltxsschema xmlnsxs"http//www.w3.org/2001/XMLSch
  ema"gt
• ltxselement name"article"gt
• ltxscomplexTypegt
• ltxssequencegt
• ltxselement name"title"
  type"xsstring"/gt
• ltxselement name"author"
  type"xsstring" maxOccurs"unbounded"/
  gt
• ltxselement name"affiliation"
  type"xsstring"/gt
• lt/xssequencegt
• lt/xscomplexTypegt
• lt/xselementgt
• lt/xsschemagt

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Third layer RDF RDF Schema

• RDF is a means to make statements that are
  machine-processable
• RDF short for Resource Description Framework
• Goal add formal semantics to the web

51
Example
Object or the value of the property
Resource identified by an URI
Property characterises the resource
http//www.kahosl.be/articleX.xml
Sep Ducamaercke
creator

• ArticleX has creator Sep Ducamaercke
• RDF is just a model for representing metadata
• Representation labeled graphs or translate to
  XML

ltrdfRDF xmlnsrdfhttp//www.w3.org/1999/02/22-r
df-syntax-ns xmlnshttp//sep.ducamaer
cke.net/rdfexamplesgt ltrdfDescription
abouthttp//www.kahosl.be/articleX.xmlgt
ltcreatorgtSep Ducamaerckelt/creatorgt
ltrdfDescriptiongt ltrdfRDFgt
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RDF Schema

• On top of RDF OO type system, named RDF Schema
• RDF Schema is a data typing system for RDF
• Difference between XML Schema and RDF Schema
• XML Schema is about syntax
• RDF Schema says something about the
  interpretation of RDF statements

53
Fourth layer Ontology language

• Need of a language to express ontologies in
• Newest languages use RDFS as a starting point
• DAMLOIL or OWL (http//www.w3.org/2001/sw/WebOnt/
  )
• These language provide methods of saying things
  such as inverses, unambiguous properties, unique
  properties, lists, restrictions, cardinalities,
  pair wise disjoint lists, datatypes,

54
Fifth layer Logic

• This part the following parts have not been
  developed yet
• Logic layer permits to state any logical
  principle and permits the computer to reason (by
  inference) using things from the lower layers
• Ex person sells gt 100 products ? person ?
  supersalesman club

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Sixth layer Proof

• Once we have systems that follow logic it makes
  sense to use them to prove things
• People around the world could write logic
  statements
• The machine could follow these Semantic links
  to construct proofs

56
Seventh layer Trust

• Not a real physical layer
• When the lower layers are ready there will be
  trust
• Metaphor tells that received data on the SW can
  be trusted
• To reach trust people should attach a digital
  signature

57
RDF(S) References

• http//www.w3.org/TR/rdf-primer/
• http//www.cs.vu.nl/marta/wbkr/slides/wbkr_c4.pdf
  
• http//www710.univ-lyon1.fr/champin/rdf-tutorial/
  

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More info about the Semantic Web

• T. Berners-Lee, James Hendler and Ora Lassila,
  The Semantic Web, Scientific American, May 2001.
  (http//www.scientificamerican.com/2001/0501issue/
  0501berners-lee.html)
• S. B. Palmer, The Semantic Web, Taking Form.
  (http//infomesh.net/2001/06/swform/)
• http//ingenieur.kahosl.be/projecten/swa2002

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Gebruikte Tools
60
Developing ontologies with OilEd

• Crash course in using OilEd
• http//oiled.man.cs.uk

61
References

• Tutorial on OilEd http//oiled.man.ac.uk/tutorial
  /
• Ontology Development 101 A Guide to Creating
  Your First Ontology (http//protege.stanford.edu/p
  ublications/ontology_development/ontology101-noy-m
  cguinness.html)
• Warning Above paper uses Protégé instead of OilEd

62
OilEd was used for

• Creating our ontology
• Representing the ontology in a JTree (we adapted
  some of the classes of OilEd) in the mapping
  component (see later)

63
OilEd short

• Creating classes (super and subclasses
  (taxonomy))
• Creating properties (super, inverse and
  subproperties)
• subClassOf and sameClassAs
• Reasoner
• Axioms (disjoint subclass)
• Creating restrictions

64
An ontology for animals

• To get acquainted with OilEd a little exercise
  (taken from http//oiled.man.ac.uk/tutorial/)
• We will make an ontology of animals

65
Create classes

• Make the superclass animal
• Add the subclasses cat, sheep, cow, giraffe
• Add mad cow as subclass of cow

66
Properties

• View class hierarchy right click on one of the
  classes and select show hierarchy
• Add properties to our classes therefore define
  properties
• Define the properties eats and eaten by
• Eats is inverse property of eaten by
• Domain of eats is animal, range of eaten by is
  animal
• Describe classes with the assistance of
  properties (restrictions)

67
Restrictions

• Restriction is made up of
• Property along which the class is restricted
• Type of filler for property
• Filler for the property
• Select animal, add restriction along eats, select
  filler of Thing
• Add 2 extra classes dog and bone (no subclass of
  animal)
• Select dog and add restriction along eats (type
  filler class bone)

68
Reasoner

• Start the reasoner
• Verify the model
• View the hierarchy model
• What is the result?
• Discard changes
• Verify the model again
• Commit changes

69
Individuals

• Add class heavenly body
• Select tab Individuals
• Add Individual sun (is an instance of heavenly
  body)
• Add moon and mars

70
Sets

• Add property howls at
• Add class wolf (no superclass)
• Add restriction along howls at
• Filler type set, choose moon

71
SubclassOf vs SameClassAs

• SubclassOf ? descriptions are necessary
  conditions. In other words necessary for class
  membership, not sufficient to describe membership
• SameClassAs ? descriptions are necessary and
  sufficient conditions. In other words necessary
  for class membership, and sufficient to describe
  membership
• SameClassAs ? defined description (complete
  definition)
• SubclassOf ? primitive description

72
SubclassOf vs SameClassAs

• Add class person (no superclass)
• Add class werewolf (subclass of person)
• Add restriction to werewolf (property of howls
  at, filler type set (moon))
• Verify!
• View class hierarchy! Comment?
• Change Property setting from SubclassOf to
  SameClassAs (of the class Wolf)
• Verify model and view class hierarchy

73
Restriction type (has-class to-class)

• Until now only used has-class
• Example with other kinds of restrictions
• Add class plant with subclass grass
• Add vegetarian (subclass of animal and defined as
  SameClassAs)
• Property restriction eats, filler plant
• Change superclass of cow to vegetarian
• Add new disjoint axiom plant animal are
  disjoint
• Add property restriction eats with filler sheep
  to mad cow
• Verify model! Remarks?

74
To-class

• Vegetarians eat only plants (change restriction
  to to-class)
• Select vegetarian, select restriction, change
  type to to-class
• Verify model
• Inconsistency (mad cow)

75
Restriction types

• Restriction types ? logical quantifiers
• Has-class ? ?
• To-class ? ?

76
Restriction type - cardinality

• This allows us to define the number of fillers a
  slot may have
• Example
• Add new subclass of animal called biped
• Set SameClassAs property and add property
  restriction on has foot with filler foot
• Change restriction to exact cardinality 2
• Select person class

77
Restriction type - cardinality

• Create restriction on has foot with filler foot
• Change cardinality of restriction to exact 2
• Verify model!
• Person should appear under biped

78
Developed ontologies

• Developed 2 ontologies (in OilEd NotePad)
• School timetabling ontology (loosely based on
  OZONE)
• Ontology for events (loosely based on iCalendar)

79
iCalendar

• iCalendar document-based format for describing
  events, to-do lists and journals.
• Includes also times, dates, people, events,
  locations
• Used in calendaring and scheduling applications
  of
• most major desktop and
• PDA personal information managers.
• Initiative to share calendars on the Internet
• Described in IETF 2445 (http//www.ietf.org/rfc/rf
  c2445.txt)

80
WordNet JWNL
81
WordNet

• Dictionary with knowledge of a native English
  speaker
• English nouns, verbs, adjectives and adverbs are
  organized into synonym sets
• Different relations link the synonym sets

82
JWNL (Java WordNet Library)

• Java API for accessing WordNet
• net.didion.jwnl.data all data objects that
  contain information from the dictionary
• net.didion.jwnl.data.list objects that hold the
  results of relationship operations
• net.didion.jwnl.data.relationship Tools for
  finding pointer relationships between two words.
• net.didion.jwnl.dictionary interface into the
  dictionary, contains all the methods needed for
  looking up words

83

• import net.didion.jwnl.
• import net.didion.jwnl.dictionary.
• import net.didion.jwnl.data.
• import net.didion.jwnl.data.list.
• import net.didion.jwnl.util.
• import java.io.
• public class Example
• public static void main(String args)    
  try            JWNL.initialize(new
  FileInputStream("C\\jwnl\\file_properties.xml"))
              IndexWord W1
  Dictionary.getInstance().getIndexWord(POS.NOUN,
  args0)            IndexWord W2
  Dictionary.getInstance().getIndexWord
  (POS.NOUN, args1)               
  RelationshipList list                 
  Relationship.findRelationships(W1.getSense(1),
  W2.getSense(1),
  
  PointerType.HYPERNYM)           
  System.out.println("Relationship between "
  W1.getLemma()
  " and " W2.getLemma()
  "")            PointerTargetNodeList ptnl
  ((Relationship)list.get(0)).getNodeList()       
      

84

• int commonParentIndex
• ((AsymmetricRelationship)l
  ist.get(0)).getCommonParentIndex()           
  PointerTargetNode ptn
  (PointerTargetNode) ptnl.get(commonParentIndex) 
             Synset synset ptn.getSynset()      
        for(int i0 iltsynset.getWordsSize()
  i)                           
  System.out.print(synset.getWord(i).getLemma() "
  ")                        System.out.println()
                  catch(Exception e)       
              e.printStackTrace()           
  System.exit(-1)            

85
Output

• C\ gt java Relation ear noseRelationship between
  ear and nosesense_organ sensory_receptor
  receptor
• C\ gt java Relation nurse teacherRelationship
  between nurse and teacherprofessional
  professional_person

86
Manipulating XML documents

• JDOM
• http//jdom.org

87
JDOM

• What? Open source, tree-based API for
  processing/manipulating/parsing/creating XML
  data/documents with Java
• JDOM represents an XML document as tree composed
  of elements, attributes, comments, processing
  instructions, text nodes, CDATA,
• Entire tree is available at any time
• If document is loaded into memory, the document
  can be modified by JDOM

88
JDOM

• JDOM tree is fully read-write
• All parts of tree can be moved, deleted, and
  added to
• After finishing working in memory serialise it
  back to disk or onto a stream

89
JDOM references

• Java XML, Brett McLaughlin, OReilly (ISBN
  0-596-00197-5)
• Processing XML with Java, Elliotte Rusty Harold,
  Addison-Wesley Pub Co (ISBN 0201771861), also
  available on-line http//cafeconleche.org/books/x
  mljava/
• Simplify XML programming with JDOM, Wes Biggs and
  Harry Evans, IBM DeveloperWorks
  (http//www-106.ibm.com/developerworks/java/librar
  y/j-jdom/)

90
JDOM was used for

• Creating the constraints in XML

91
Document class

• Documents are in the package org.jdom.Document
• From scratchDocument doc new Document(new
  Element(root))

92
Create a document element

• Create simple document in JDOMDocument doc
  new Document()Element e new
  Element(root)e.setText(This is the
  root)doc.addContent(e)
• Or more compactDocument doc new Document (new
  Element(root).setText(This is the root))

93
Element class

• Get root element
• Element root doc.getRootElement()
• list of all child elements
• List allChildren root.getChildren()
• get those elements that have this given name
• List namedChildren root.getChildren(name)
• get 1st element with a given name
• Element child root.getChild(name)

94
Well-Formedness

• Element constructor check if the element is legal
  (ex. No forbidden characters)
• Add/remove method checks structure
• No loops in the tree
• Exactly one root
• Consistent namespaces

95
Attribute class

• Elements may have attributesltaddress
  streetGebr.Desmetstraat 1 cityGent
  zip9000gtlt/addressgt
• Get attributeString street address.getAttribut
  eValue(street)int zip address.getAttribute(
  zip).getIntValue()
• Set attributeaddress.setAttribute(country,
  Belgium)
• Remove attributeaddress.removeAttribute(country
  )

96
Element content

• Element may have text contentltcitygtGentlt/citygt
• To get the contentString city
  element.getText()This returns \n Gent\n
• String city element.getTextTrim()returns Gent
• To change the text contentelement.setText(A
  new description)

97
XMLOutputter Class

• Different kinds of outputDocument doc new
  Document()XMLOutputter outp new
  XMLOutputter()
• Rawoutp.output(doc, fileOutputStream)
• compactoutp.setTextTrim(true)outp.output(doc,
  socket.getOutputStream())
• pretty outputoutp.setIndent( )outp.setNewline
  s(true)outp.output(doc, System.out)

98
Writing XML documents

• import org.jdom.
• import org.jdom.output.XMLOutputter
• import java.math.BigInteger
• import java.io.IOException
• public class FibonacciJDOM
• public static void main(String args)
• Element root new Element("Fibonacci_Numbers")
  BigInteger low BigInteger.ONE BigInteger
  high BigInteger.ONE for (int i 1 i lt 5
  i) Element fibonacci new
  Element("fibonacci") fibonacci.setAttribute("
  index",String.valueOf(i)) fibonacci.setText(l
  ow.toString()) root.addContent(fibonacci)

99
Writing XML documents

• BigInteger temp high high
  high.add(low) low temp
• Document doc new Document(root)
• // serialize it onto System.out try
  XMLOutputter serializer new XMLOutputter()
  serializer.setIndent( ) serializer.setNew
  lines(true) serializer.output(doc,
  System.out)
• catch (IOException e)
• System.err.println(e)

• Demo

100
DTD

• Suppose the DTD of the previous XML file looks
  likelt!ELEMENT Fibonacci_Numbers
  (fibonacci)gtlt!ELEMENT fibonacci
  (PCDATA)gtlt!ATTLIST fibonacci index CDATA
  IMPLIEDgt
• DocType class represents DTDsDocType type new
  DocType("Fibonacci_Numbers", "fibonacci.dtd")
• Add to the previous JDOM program the following
  linesDocType type new DocType("Fibonacci_Numbe
  rs", "fibonacci.dtd") Document doc new
  Document(root, type)

101
Navigating JDOM Trees

• Everything is an object cast to right type
• Done by instanceof
• getChildren() returns only elements (everything
  else is missed) -gt returns a java.util.List
• To get everything use getContent() -gt returns a
  java.util.List
• In this case not everything is Element

102
Reading an XML File

• import org.jdom.
• import org.jdom.input.SAXBuilder
• import java.io.IOException
• import java.util.
• public class NodeLister
• public static void main(String args)
• if (args.length 0)
• System.out.println("Usage java NodeLister
  URL")
• return
• SAXBuilder builder new SAXBuilder()
• try Document doc builder.build(args0)
  listNodes(doc, 0)

103
Big example

• // indicates a well-formedness error
• catch (JDOMException e)
• System.out.println(args0 " is not
  well- formed.")
• System.out.println(e.getMessage())
• catch (IOException e)
• System.out.println(e)
• public static void listNodes(Object o, int depth)
  printSpaces(depth) if (o instanceof Element)
  Element element (Element) o
  System.out.println("Element "
  element.getName()) List children
  element.getContent() Iterator iterator
  children.iterator() while (iterator.hasNext())
  Object child iterator.next() listNodes(c
  hild, depth1)

104
Big example

• else if (o instanceof Document)
  System.out.println("Document") Document doc
  (Document) o List children
  doc.getContent() Iterator iterator
  children.iterator() while (iterator.hasNext())
  Object child iterator.next() listNodes(c
  hild, depth1) else if (o instanceof
  Comment) System.out.println("Comment")
  else if (o instanceof CDATA) System.out.printl
  n("CDATA section") // CDATA is a subclass of
  Text so this test must come // before the test
  for Text. else if (o instanceof Text)
  System.out.println("Text") else if (o
  instanceof EntityRef) System.out.println("Entit
  y reference")

105
Big example

• else if (o instanceof ProcessingInstruction)
  System.out.println("Processing Instruction")
  else // This really shouldn't
  happen System.out.println("Unexpected type
  "o.getClass())
• private static void printSpaces(int n) for
  (int i 0 i lt n i) System.out.print('
  ')

• Demo

106
What JDOM does not do

• JDOM cannot handle docs larger than the available
  memory
• JDOM treats the doc as logical whole (ex. is the
  character literally input or input via character
  reference, or parsing a doc with JDOM and writing
  it out can create little differences)
• JDOM does not provide any real model of the DTD
• No standard solution to traverse a tree

107
Introduction to the JENA RDF API

108
Jena was used for

• Querying the mapped RDF data file

109
JENA description

• Jena is a Java framework for building Semantic
  Web applications. It provides a programmatic
  environment for RDF, RDFS and OWL, including a
  rule-based inference engine.
• Valid since version 2.0 (appeared summer 2003)
• The Jena Framework includes
• A RDF API
• Reading and writing RDF in RDF/XML, N3 and
  N-Triples
• An OWL API
• In-memory and persistent storage
• RDQL a query language for RDF
• Taken from the Jena website

110
Semantic weblayers
RDF, RDFS, DAMLOIL, OWL, Jena (HP)
XML, XML Schema,DOM, JDOM, SAX,
111
JENA

• JENA
• Full-featured Java API for RDF
• Open source API
• Accessible at Source Forge (http//jena.sourceforg
  e.net) also avaliable at http//www.hpl.hp.com/sem
  web/jena.htm

112
JENA interfaces

• Vocabulary
• Model A set of statements
• Statement A triple of R, P, O
• Resource Subject, named by a URI
• Property characterises resource
• Object May be a resource or a literal
• Literal Non-nested object
• Container Special resource, collection of
  things
• BAG Unordered collection
• SEQ Ordered collection
• ALT Unordered collection except first element

113
ltlt interface gtgt RDFNode
ltlt interface gtgt Resource
ltlt interface gtgt Literal
ltlt interface gtgt Property
ltlt interface gtgt Statement
ltlt interface gtgt Container
ltlt interface gtgt Bag
ltlt interface gtgt Seq
ltlt interface gtgt Alt
114
(No Transcript)
115
Structure of RDF data (Model)
value
NAME
SESSION
SESSION_ID
value
value
value
NUMBER_OF_PEOPLE
TIMESLOT_ID
value
DTSTART
DTEND
value
TIMESLOT
value
LOCATION_ID
value
NAME
LOCATION
value
HAS_CAPACITY
value
DATE_ID
value
DAY
DATE
WEEKNR
value
value
value
NAME
SESSIONGROUP_ID
SESSION-GROUP
value
STUDENTGROUP_ID(gt1)
ATTENDEE
value
TEACHERGROUP_ID
TEACHER-GROUP
TEACHER_ID(gt1)
value
116
JENA Examples

• Ex 1 Building simple RDF Graph with Jena
• Ex 2 Blank node example
• Ex 3 List the statements in the graph
• Ex 4 Writing RDF
• Ex 5 Reading RDF to a Model object
• Ex 6 Navigating Model object
• Ex 7 Querying a Model object 1
• Ex 8 Querying a Model object 2
• Ex 9 Using containers

117
import com.hp.hpl.jena.rdf.model. import
com.hp.hpl.jena.vocabulary. import
java.io.PrintWriter public class Example_1_new
extends Object // Some definitions static
String personURI "http//somewhere/JohnSmith"
static String fullName "John Smith"
public static void main (String args) try
// Create an empty graph Model
model ModelFactory.createDefaultModel()
// Create the resource Resource
johnSmith model.createResource(personURI)
// Add the property johnSmith.addProper
ty(VCARD.FN, fullName) // Print RDF/XML
of model to system output model.write(new
PrintWriter(System.out)) catch (Exception
e) System.out.println("Failed " e)

vcard.FN
http//somewhere/JohnSmith
John Smith
Ex 1 Building a simple RDF Graph with Jena
118
// Some definitions String personURI
"http//somewhere/JohnSmith" String givenName
"John" String familyName "Smith" String
fullName givenName " " familyName //
Create an empty Model Model model
ModelFactory.createDefaultModel() // Create the
resource and add the properties cascading
style Resource johnSmith model.createResource(pe
rsonURI)
.addProperty(VCARD.FN, fullName)
.addProperty(VCARD.N, model.createResourc
e()
.addProperty(VCARD.Given, givenName)
.addProperty(VCARD.Family,
familyName) )
http//somewhere/JohnSmith
vcard.FN
vcard.N
John Smith
vcard.Given
vcard.Family
John
Smith
Ex 2 Blank node example
119
List statements // List the statements in the
Model StmtIterator iter model.listStatements()
// Print out the predicate, subject and object
of each statement while (iter.hasNext())
Statement stmt iter.nextStatement()
Resource subject stmt.getSubject() // Get
the subject Property predicate
stmt.getPredicate() // Get the predicate
RDFNode object stmt.getObject() // Get
the object System.out.print(subject.toString(
)) System.out.print(" " predicate.toString()
" ") if (object instanceof Resource)
System.out.print(object.toString()) else
// object is a literal System.out.print("
\"" object.toString() "\"")
System.out.println(" .")
Object can be an instance of a resource or a
literal
Ex 3 List the statements in the graph
120
List statements / Result http//somewhere/JohnSm
ith http//www.w3.org/2001/vcard-rdf/3.0N
anon14df86ecc3dee17b-7fff . anon14df86ecc3de
e17b-7fff http//www.w3.org/2001/vcard-rdf/3.0Fa
mily "Smith" . anon14df86ecc3dee17b-7fff
http//www.w3.org/2001/vcard-rdf/3.0Given "John"
. http//somewhere/JohnSmith http//www.w3.org/20
01/vcard-rdf/3.0FN "John Smith" .
http//somewhere/JohnSmith
vcard.FN
vcard.N
John Smith
vcard.Given
vcard.Family
John
Smith
Ex 3
121
Reading RDF InputStream in Example_5_new.class.
getClassLoader()
.getResourceAsStream(inputFileName) model.read(ne
w InputStreamReader(in), "") Writing RDF / RDF
XML form model.write(new PrintWriter(System.out))
Writing RDF / RDF XML abbreviated
syntax model.write(new PrintWriter(System.out),
"RDF/XML-ABBREV") Writing RDF / N-Triples
specification model.write(new PrintWriter(System.
out), "N-TRIPLE")
Ex 4 5 writing and reading RDF
122
Navigating a Model / 1 // Read the RDF/XML
file model.read(new InputStreamReader(in),
"") // Retrieve the John Smith vcard resource
from the model Resource vcard
model.getResource(johnSmithURI) // Retrieve
the value of the N property Resource name
(Resource) vcard.getProperty(VCARD.N).getObject()
// Retrieve the given name property String
fullName vcard.getProperty(VCARD.FN).getString()
// Add two nick name properties to
vcard vcard.addProperty(VCARD.NICKNAME,"Smithy").a
ddProperty(VCARD.NICKNAME, "Adman")
Ex 6
123
Navigating a Model / 2 // Read the RDF/XML
file model.read(new InputStreamReader(in),
"") // Retrieve the John Smith vcard resource
from the model Resource vcard
model.getResource(johnSmithURI) // Retrieve
the value of the N property Resource name
(Resource) vcard.getProperty(VCARD.N).getObject()
// Retrieve the given name property String
fullName vcard.getProperty(VCARD.FN).getString()
// Add two nick name properties to
vcard vcard.addProperty(VCARD.NICKNAME,"Smithy").a
ddProperty(VCARD.NICKNAME, "Adman")


Ex 6
124
Navigating a Model / 3 // Read the RDF/XML
file model.read(new InputStreamReader(in),
"") // Retrieve the John Smith vcard resource
from the model Resource vcard
model.getResource(johnSmithURI) // Retrieve
the value of the N property Resource name
(Resource) vcard.getProperty(VCARD.N).getObject()
// Retrieve the given name property String
fullName vcard.getProperty(VCARD.FN).getString()
// Add two nick name properties to
vcard vcard.addProperty(VCARD.NICKNAME,"Smithy").a
ddProperty(VCARD.NICKNAME, "Adman")
vcard
Ex 6
125
Navigating a Model / 4 // Read the RDF/XML
file model.read(new InputStreamReader(in),
"") // Retrieve the John Smith vcard resource
from the model Resource vcard
model.getResource(johnSmithURI) // Retrieve
the value of the N property Resource name
(Resource) vcard.getProperty(VCARD.N).getObject()
// Retrieve the given name property String
fullName vcard.getProperty(VCARD.FN).getString()
// Add two nick name properties to
vcard vcard.addProperty(VCARD.NICKNAME,"Smithy").a
ddProperty(VCARD.NICKNAME, "Adman")
vcard
name
Ex 6
126
Navigating a Model / 5 // Read the RDF/XML
file model.read(new InputStreamReader(in),
"") // Retrieve the John Smith vcard resource
from the model Resource vcard
model.getResource(johnSmithURI) // Retrieve
the value of the N property Resource name
(Resource) vcard.getProperty(VCARD.N).getObject()
// Retrieve the given name property String
fullName vcard.getProperty(VCARD.FN).getString()
// Add two nick name properties to
vcard vcard.addProperty(VCARD.NICKNAME,"Smithy").a
ddProperty(VCARD.NICKNAME, "Adman")
vcard
fullname
name
Ex 6
127
RDQL query language

• RDQL
• Provides a way to specify a graph pattern
• RDQL yields a set of matches
• It results a set of bindings
• Binding set of name-value pairs

128
RDQL query language

• RDQL Syntax (clauses) ? SQL Syntax
• SELECT Identifies the variables to be returned
  to the application
• FROM Specifies the model by URI
• WHERE Specifies the graph pattern as a list of
  triple patterns
• AND Specifies the boolean expressions
• USING A way to shorten the length of URIs

129
RDQL query language examples
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
130
SELECT ?x WHERE (?x lthttp//www.w3.org/2001/vcard
-rdf/3.0FNgt "John Smith")
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
131
SELECT ?x WHERE (?x lthttp//www.w3.org/2001/vcard
-rdf/3.0FNgt "John Smith")
Result x
lthttp//somewhere/J
ohnSmith/gt
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
132
SELECT ?x, ?fname WHERE (?x lthttp//www.w3.org/20
01/vcard-rdf/3.0FNgt ?fname)
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
133
SELECT ?x, ?fname WHERE (?x lthttp//www.w3.org/20
01/vcard-rdf/3.0FNgt ?fname)
Result x fname

lthttp//somewhere/JohnSmith/gt "John
Smith" lthttp//somewhere/RebeccaSmith/gt "Becky
Smith" lthttp//somewhere/SarahJones/gt "Sarah
Jones" lthttp//somewhere/MattJones/gt "Matt
Jones"
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
134
SELECT ?givenName WHERE (?y lthttp//www.w3.org/20
01/vcard-rdf/3.0Familygt "Smith") (?y
lthttp//www.w3.org/2001/vcard-rdf/3.0Givengt
?givenName)
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
135
SELECT ?givenName WHERE (?y lthttp//www.w3.org/20
01/vcard-rdf/3.0Familygt "Smith") (?y
lthttp//www.w3.org/2001/vcard-rdf/3.0Givengt
?givenName)
Result givenName "John" "Rebecca"
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
136
SELECT ?resource ?givenName WHERE (?resource
lthttp//www.w3.org/2001/vcard-rdf/3.0Ngt ?z),
(?z lthttp//www.w3.org/2001/vcard-rdf/3.0Givengt
?givenName)
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
137
SELECT ?resource ?givenName WHERE (?resource
lthttp//www.w3.org/2001/vcard-rdf/3.0Ngt ?z),
(?z lthttp//www.w3.org/2001/vcard-rdf/3.0Givengt
?givenName)
Result resource
givenName
lthttp//somewhere/JohnSmith/gt "John"
lthttp//somewhere/RebeccaSmith/gt
"Rebecca" lthttp//somewhere/SarahJones/gt
"Sarah" lthttp//somewhere/MattJones/gt
"Matthew"
vCardFN
John Smith
http//somewhere/JohnSmith/
vCardGiven
John
vCardN
vCardFamily
Smith
vCardFN
Sarah Jones
http//somewhere/SarahJones/
vCard Given
Sarah
vCardN
vCard Family
Jones
vCardFN
Matt Jones
http//somewhere/MattJones/
vCard Given
Matthew
vCardN
vCard Family
Jones
vCardFN
Becky Smith
http//somewhere/RebeccaSmith/
vCard Given
Rebecca
vCardN
vCard Family
Smith
138
RDQL query language examples

• Other features
• USING Clause
• SELECT ?resource WHERE (?resource infoage
  ?age) AND ?age gt 24USING info FOR
  http//somewhere/peopleInfo
• Querying for PropertiesSELECT ?propWHERE
  (lthttp//somewhere/JohnSmith/gt , ?prop, "John
  Smith")

139

• SELECT ?SESSION_ID, ?NUMBER_OF_PEOPLE,
  ?TIMESLOT_ID, ?DTSTART, ?DTEND,
  ?SessionGroup_ID, ?DATE_ID, ?Day, ?LOCNAME,
  ?LOCATION_ID, ?has_capacity, ?COURSE, ?WeekNr,
  ?WKDY, ?StudentGroup_ID, ?Teacher_ID,
  ?TeacherGroup_ID
• WHERE (?x, lthybridSESSION_IDgt, ?SESSION_ID),
• (?x, lthybridNAMEgt, ?COURSE),
• (?x, lthybridNUMBER_OF_PEOPLEgt,
  ?NUMBER_OF_PEOPLE),
• (?x, lthybridtimeslotgt, ?z),
• (?z, lthybridTIMESLOT_IDgt, ?TIMESLOT_ID),
• (?z, lthybridDTSTARTgt, ?DTSTART),
• (?z, lthybridDTENDgt, ?DTEND),
• (?x, lthybridlocationgt, ?v),
• (?v, lthybridLOCATION_IDgt, ?LOCATION_ID),
• (?v, lthybridNAMEgt, ?LOCNAME),
• (?v, lthybridHAS_CAPACITYgt, ?has_capacity),
• (?x, lthybriddategt, ?r),
• (?r, lthybridDATE_IDgt, ?DATE_ID),
• (?r, lthybridDAYgt, ?Day),
• (?r, lthybridWEEKNRgt, ?WeekNr),
• (?r, lthybridNAMEgt, ?WKDY),
• (?x, lthybridattendeegt, ?m),
• (?m, lthybridsessiongroupgt, ?n),

140
Using RDQL from JAVA

• Key classes
• Query The query itself
• QueryExection The execution algorithm interface
• QueryEngine The local execution algorithm
• QueryResults The results iterator
• ResultBinding One collection of variable
  bindings

141
Using RDQL from JAVA

• JAVA code
• String queryString "SELECT ?x, ?fname ""WHERE
  (?x, lthttp//www.w3.org/2001/vcard-rdf/3.0FNgt,
  ?fname)"
• Query query new Query(queryString)
• query.setSource(model)
• QueryExecution qe new QueryEngine(query)
• QueryResults results qe.exec()
• for ( Iterator iter results iter.hasNext())
  
• ResultBinding res (ResultBinding)iter.next()
• Object x res.get("x")
• Object fname res.get("fname")
• System.out.println("x "x" fname "fname)
  
• results.close()

142
References

• Practical RDF, Shelley Powers http//safari.oreil
  ly.com/?XmlId0-596-00263-7
• Jena Tutorial http//jena.sourceforge.net/tutoria
  l/

143
Database to RDF Mapping Language and Processor

• D2R Map

144
References

• D2R MAP - A Database to RDF Mapping Language,
  Chris Bizer (http//www.wiwiss.fu-berlin.de/suhl/b
  izer/d2rmap/www2003-D2R-Map.pdf)
• D2R language specification, Chris Bizer
  (http//www.wiwiss.fu-berlin.de/suhl/bizer/d2rmap/
  D2R_language20specification.pdf)

145
Why D2R Map?

• If you want to use data (stored in DB) on the
  Semantic Web map it into RDF (this is the format
  for the Semantic Web)
• Map relational database model to graph-based RDF
  data model
• D2R Map XML-based language to describe these
  mappings
• Flexible mapping (no change of existing
  relational database schema)
• Adding SQL statements directly in the mapping
  rules

146
The Language

• For each class in ontology ClassMap element is
  used
• DataTypePropertyBridge elements for literal
  properties (with XML datatypes)
• References to external resources
  ObjectPropertyBridge element

147
Example

• ltd2rClassMap d2rtype"hybridSESSION"
  d2rsql"SELECT FROM ((Session INNER JOIN
  TimeSlot ON Session.TimeSlotIDTimeSlot.TimeSlotI
  D) INNER JOIN Room ON Session.RoomIDRoom.RoomID)
  INNER JOIN TimeDate ON TimeDate.TimeDateIDSessi
  on.TimeDateID" d2rgroupBy"Session.SessionID"gt
• ltd2rDatatypePropertyBridge d2rproperty"hybrid
  SESSION_ID" d2rcolumn"Session.SessionID"/gt
• ltd2rDatatypePropertyBridge d2rproperty"hybrid
  NUMBER_OF_PEOPLE_ID" d2rcolumn"Session.SGroupID
  "/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridti
  meslot d2rreferredClass"hybridTIMESLOT
  d2rreferredGroupBy"TimeSlot.TimeSlotID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridlo
  cation d2rreferredClass"hybridLOCATION
  d2rreferredGroupBy"Room.RoomID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridda
  te d2rreferredClass"hybridDATE
  d2rreferredGroupBy"TimeDate.TimeDateID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridat
  tendee d2rreferredClass"hybridATTENDEE
  d2rreferredGroupBy"Session.SessionID"/gt
• lt/d2rClassMapgt

148
ClassMap

• Used to map the result of a SQL query to a class
  or to a group of similar classes
• 2 (required) attributes sql statement (select
  data from the DB) and groupBy attribute
  (columnlist to group the rows of the ResultSet)

149
ClassMap example
Table Products

• D2R Map Fragment

• ltd2rClassMap d2rtypegoodsProduct
  d2rsqlSELECT from Products
  d2rgroupBygoods.SNr d2ruriPatternhttp//ex
  ample.org/goods_at__at_Products.SerialNR_at__at_gtltd2rDatat
  ypePropertyBridge d2rpropertygoodsname
  d2rcolumnProducts.Product_Name/gtltd2rDatatype
  PropertyBridge d2rpropertygoodshasKeyword
  d2rcolumnProducts.Keyword/gt
• lt/d2rClassMapgt

• RDF result

ltrdfRDFgtltgoodsProduct rdfabouthttp//example
.org/goodsQ8GR2 goodsnameDell Dimension
V400gt ltgoodshasKeywordgt256 MB
RAMlt/goodshasKeywordgt ltgoodshasKeywordgt19
monitorlt/goodshasKeywordgt lt/rdfRDFgt
150
Property Mappings

• Define bridges between columns of the result set
  and instance properties
• 2 different kinds
• DatatypePropertyBridge defines bridge between
  column of result set and literal property of
  instances
• ltd2rDatatypePropertyBridge d2rproperty"hybridS
  ESSION_ID" d2rcolumn"Session.SessionID"/gt
• ObjectPropertyBridgedefines bridge between
  column of result set and object property of
  instances
• ltd2rObjectPropertyBridge d2rproperty"hybridloc
  ation d2rreferredClass"hybridLOCATION
  d2rreferredGroupBy"Room.RoomID"/gt

Reference to a d2rClassMap
151
Elaborated example

• lt?xml version"1.0" encoding"UTF-8"?gt
• ltd2rMap xmlnsd2r"http//www.wiwiss.fu-berlin.de
  /suhl/bizer/D2RMap/0.1" d2rversionInfo"Id
  AtlasMap.d2r,xml, v 0.1 2003/01/27 Peter Exp "gt
• ltd2rProcessorMessage d2routputFormat"RDF/XML-A
  BBREV"/gt
• ltd2rDBConnection d2rjdbcDriver"com.microsoft.j
  dbc.sqlserver.SQLServerDriver" d2rjdbcDSN"jdbcm
  icrosoftsqlserver//HAWKING1433UserAtlasUser2
  PasswordgmatlasdbAtlas" d2rlogin"AtlasUser2"
  d2rpassword"gmatlas"/gt
• ltd2rNamespace d2rprefix"hybrid"
  d2rnamespace"http//project.kahosl.be/cofftea/20
  03/01/hybrid.daml"/gt
• ltd2rNamespace d2rprefix"daml"
  d2rnamespace"http//www.daml.org/2001/03/damloi
  l"/gt
• ltd2rNamespace d2rprefix"rdf"
  d2rnamespace"http//www.w3.org/1999/02/22-rdf-sy
  ntax-ns"/gt
• ltd2rNamespace d2rprefix"schooltimetabling"
  d2rnamespace"http//project.kahosl.be/cofftea/20
  03/01/schooltimetabling.daml"/gt

152
Elaborated example

• ltd2rClassMap d2rtype"hybridSESSION"
  d2rsql"SELECT FROM ((Session INNER JOIN
  TimeSlot ON Session.TimeSlotIDTimeSlot.TimeSlotI
  D) INNER JOIN Room ON Session.RoomIDRoom.RoomID)
  INNER JOIN TimeDate ON TimeDate.TimeDateIDSession
  .TimeDateID" d2rgroupBy"Session.SessionID"gt
• ltd2rDatatypePropertyBridge d2rproperty"hybri
  dSESSION_ID" d2rcolumn "Session.SessionID"/gt
• ltd2rDatatypePropertyBridge d2rproperty"hybri
  dNUMBER_OF_PEOPLE_ID" d2rcolumn "Session.SGrou
  pID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridt
  imeslot" d2rreferredClass"hybridTIMESLOT"
  d2rreferredGroupBy "TimeSlot.TimeSlotID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridl
  ocation" d2rreferredClass"hybridLOCATION"
  d2rreferredGroupBy "Room.RoomID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybridd
  ate" d2rreferredClass"hybridDATE"
  d2rreferredGroupBy "TimeDate.TimeDateID"/gt
• ltd2rObjectPropertyBridge d2rproperty"hybrida
  ttendee" d2rreferredClass"hybridATTENDEE"
  d2rreferredGroupBy "Session.SessionID"/gt
• lt/d2rClassMapgt

153
Elaborated example

• ltd2rClassMap d2rtype"hybridDATE"
  d2rsql"SELECT FROM TimeDate"
  d2rgroupBy"TimeDate.TimeDateID"gt
• ltd2rDatatypePropertyBridge d2rproperty"hybrid
  DATE_ID" d2rcolumn"Time