The slides share experience on how to build a crawl FB content and save as RDF, then use Joseki (Jena) to serve the RDF data using SPARQL endpoint.

1. Saveface – Save Facebook’s data
as RDF graph
Using Jena, Joseki & FB graph API
Fuming Shih
fuming@mit.edu

2. About Me
• 4th year graduate student at CSAIL, working
with Hal Abelson
• Member of DIG group (decentralized
information group) at CSAIL
• Working on topics relating to privacy, mobile
context, and accountability
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3. Saveflickr
Saveface
Simond Secono's Walled Gardens Picture, taken from TimBL's presentation 3

4. Outline
• Demo Saveface SPARQL endpoint
• Overview
• Set up Joseki SPARQL endpoint
• From Protégé (data modeling) to Jena/Jaster
(RDF library/SPARQL endpoint
– Protégé
– Jastor
– Facebook graph API
– Jena
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5. Overview
• Protégé 4.1 (data modeling)
• Jastor library (RDF to POJO)
• Facebook graph API
• RestFB*
• Jena/Jastor
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6. Setup Joseki (Jena)
• Joskei is an HTTP engine that supports SPRAQL;
(use jetty, support ARQ for Jena)
– configuration as turtle file
• Get Jena 2.6.3, tdb 0.8.7, Joseki 3.4.2 at
http://sourceforge.net/projects/jena/files/
– or go to
http://dig.csail.mit.edu/2010/aintno/rdfData/aintno_j
oseki.tar.gz for everything in one zip file
– Jena is now an Apache Incubator program
(http://incubator.apache.org/jena/index.html)
source: http://ricroberts.com/articles/installing-jena-and-joseki-on-os-x-or-linux 6

7. Setup environment
• export JOSEKIROOT=/path/to/Joseki-3.4.2
• export TDBROOT=/path/to/TDB-0.8.7
• export JENAROOT=/path/to/Jena-2.6.3
• export
CLASSPATH=.:$JENAROOT/lib/*.jar:$TDBROOT/lib/*.jar:
$JOSEIKIROOT/lib/*.jar
• export PATH=“$TDBROOT/bin:$JOSEKIROOT/bin:$PATH
• if you download the all-in-one package(* I have put all
jars under Joseki’s lib folder)
– export JOSEKIROOT="/path/to/Joseki-aintno”
– export PATH="$JOSEKIROOT/bin:$PATH”
– export CLASSPATH=".:$JOSEKIROOT/lib/*.jar"
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8. Run Joseki
• cd /path/to/Joseki
• ./bin/rdfserver
– ./bin/rdfserver - - help
(joseki.rdfserver [--verbose] [--port N] dataSourceConfigFile)
• Now open browser at http://localhost:2020/
– test some of the SPARQL query interface with example
data
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9. Joseki - Http access to SPARQL
Endpoint
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10. Saveface
• Goal: save my Facebook data as linked data
• Facebook *finally* provides restful API to
access its data (Facebook Graph API)
– http://developers.facebook.com/docs/reference/a
pi/
– graph structure (e.g. Album class)
• http://developers.facebook.com/docs/reference/api/al
bum/
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11. From Data model to Java POJO
• Used Protégé to create owl class for each of the
Facebook classes
– be aware that mapping from OO to ontology needs
cares
– serialize as RDF files
• Mapping ontologies (owl files) to JAVA classes
– used Jastor library to generates Java
interfaces, implementations, factories, and listeners
based on the properties and class hierarchies in the
Web ontologies
– easier for non-Semantic Web java developer to make
use of ontology
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12. Jastor
• Typesafe, Ontology Driven RDF Access from Java
http://jastor.sourceforge.net/
– Use Jena 2.4
• Provides an interface for
access/setting/adding event listeners to RDF
model Jastor
Operator listener
iCal SIOC
Mapping
tool
Tag FOAF
Jena2 Platform
(RDF model + Reasoning Engine +
Persistence System) RDF DB
Ontology
files
JAVA VM 12

13. Example
Create mapping
JastorContext ctx = new JastorContext();
ctx.addOntologyToGenerate(new FileInputStream("src/data/Tag.owl"),
"http://www.mit.edu/dig/ns/tag",
"edu.mit.dig.model.Tag");
JastorGenerator gen = new JastorGenerator(
new File("gensrc").getCanonicalFile(),
ctx);
gen.run();
Make use of the class
Tag tag = edu.mit.dig.model.Tag.tagFactory.createTag(NS_PREFIX + "id_1", model);
tag.addName("A tag");
tag.addX(45);
tag.addY(32);
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14. RestFB + RDF
• Facebook graph API client
• Forked RestFB 1.5.4 and added RDFUtil.java
– used java reflection to covert each FB objects in
RestFB to Jena RDF model (method toRDF())
• Default domain name for Saveface data
– http://servername:port_num/data/saveface/
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15. Demo
• git clone git@github.com:fumingshih/savefaceDemo.git
• Login to your Facebook
• Go to http://developers.facebook.com/docs/reference/api/
– click on one of the links to view your content in json format (graph)
– copy the access_token after
https://graph.facebook.com/me/friends?access_token
• Run saveface.tutorial.Exercise1.java
– paste the access_token string (* only valid for one
hour)
– change the directory for storing RDF (TDB files)
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16. Access SaveFace Data through Joseki
• Open /path/to/your/Joseki/joseki-config.ttl
• Three concepts in the configuration files
– services
• Services are the points that request are sent to
• Need to specify dataset and processor
• Note that the service reference and the routing of incoming
requests by URI as defined by web.xml have to align
– datasets
• can be path to the dataset
• or using Jena assembler description to compile different named
graphs together
– processors
• set limitations on SPARQL queries (locking, no FROM/FROM
NAMED)
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Reference: http://www.joseki.org/configuration.html

17. Configuration Example (Service)
# Service 3 - SPARQL processor only handing a given dataset(TDB)
<#service3>
rdf:type joseki:Service ;
rdfs:label "SPARQL on the named graph of saveface" ;
joseki:serviceRef "saveface" ; # web.xml must route this name to Joseki
# dataset part
joseki:dataset <#savefacedata> ;
# Service part.
# This processor will not allow either the protocol,
# nor the query, to specify the dataset.
joseki:processor joseki:ProcessorSPARQL_MultiDS ;
.
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18. Configuration Example (Dataset)
# init tdb
[] ja:loadClass "com.hp.hpl.jena.tdb.TDB" .
tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset .
tdb:GraphTDB rdfs:subClassOf ja:Model .
<#savefacedata> rdf:type tdb:DatasetTDB ;
rdfs:label "saveface dataset" ;
#change this line below to your path to the dataset
tdb:location "/Users/fuming/tmp/saveface_demo" ;
.
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19. Facebook Data as Linked Data!
• Change graph name to <urn:saveface:dataGraph:FumingShih>
in the SPARQL query
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20. References
• http://incubator.apache.org/jena/index.html
• http://www.joseki.org/
• Graph API
– http://developers.facebook.com/docs/reference/api/
• Jastor
– http://jastor.sourceforge.net/
• RestFB (http://restfb.com/ )
– FB API browser (http://zestyping.livejournal.com/257224.html)
• SavefaceDemo
– https://github.com/fumingshih/savefaceDemo
– More on Saveface demo
• http://dice.csail.mit.edu/aintno/ui/#aintno
• http://dig.csail.mit.edu/wiki/SocialWebs_Data_Crawler/RDF_Repository_Setu
p
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