distilling the Web of Data drop by drop (with Java)

distilling the Web of Data
drop by drop (with Java)

Sourcesense UK “Last Wednesday” - Davide Palmisano @dpalmisano

Wednesday, June 29, 2011

the shortest introduction
ever to the Web o f Data

Web pages markup technologies are
intended for human consumption

they let machines to present raw
data to humans

extracting valuable data may
require fancy scraping techniques

scraping: one size doesn’t fit all



<div>
<div> Canon Rebel T2i (EOS 550D) $899 </div>
<div> The Rebel T2i EOS 550D is Cannon's
top-of-the-line consumer digital SLR
camera. It can shoot up

<div> AN_UCC-13: 013803123784 </div>
<div> price: 899 USD </div>

</div>
</div>



<div>

<div> AN_UCC-13: 013803123784 </div>
what does this
</div> is this a tag mean?
</div> currency or what?


“meaning”, Joseph Kosuth, The Panza Collection, MART - Rovereto, Italy


Microformats

“Microformats are a way of adding simple markup
to human-readable data items such as events,
contact details or locations, on web pages”
Andy Mabbett

- community driven initiative
- largely adopted
- quick & dirty
- scarcely extensibility


Microformats

<div class=”hlisting item”>
<div> Canon Rebel T2i (EOS 550D) $899< /div>
<div class=”description”> The Rebel T2i EOS
550D is Cannon's
<div> AN_UCC-13: 013803123784 </div>
<div class=”price”> price: 899 USD </div>
</div>
</div>


RDFa: RDF in attribute

model your data as they were Web pages
connected with named links and properties
and embed them in your (X)HTML using
@attributes

- RDF, graph-based model
- W3C Recommandation
- highly extensible

i.e GoodRelations[1], a fully flavored
vocabulary for the e-commerce



model your data

http://mystore.com/product/5642

ex:price ex:value 899

ex:producer
ex:currency

ex:description
USD
http://canon.co.uk

The Rebel T2i EOS
550D blah blah


and then embed them in your
(X)HTML pages
<div about=”http://mystore.com/product/5642”>
<div>Canon Rebel T2i (EOS 550D) $899</div>
<div property=”gr:description”>The Rebel T2i EOS 550D
is Cannon's blah blah</div>

<div rel=”gr:hasPriceSpecification”>
<span> price:
<span property=”gr:hasCurrencyValue”>899</span>
<span property=”gr:hasCurrency”>USD</span>
</span>
</div>
</div>

HTML5: Microdata

Microdata allows nested groups of name-value
pairs to be added to HTML documents, in
parallel with the existing content

- W3C Working draft
- native of HTML5 specification
- serializable in RDF

- Google, Yahoo! and Bing endorsed Schema.org
- large adoption expected


HTML5: Microdata

<div itemscop itemtype=”http://schema.org/Offer”>
<div itemprop=”name”> Canon Rebel T2i (EOS 550D) $899
</div>
<div itemprop=”description”> The Rebel T2i EOS 550D
is Cannon's blah blah</div>

<div>
<span> price:
<span itemprop=”price”> 899 </span>
<span itemprop=”priceCurrency”> USD </span>
</span>
</div>
</div>


% of marked up Web pages

3.5

3

2.5

2

1.5

1

RDFa 0.5
hCard
adr
09/2008 xfn 0
03/2009 hReview
10/2010
data from Yahoo! [2]


tie ‘em all together

uniform, reconciled and
unified RDF representation


a drop-by-drop distiller

Anything To Triples (any23) is an open source,
Apache-licensed:

- Java library,
- Web service and
- a command-line tool

able to distill RDF triples from a
variety of semantically marked up Web
documents

http://developers.any23.org


live demo http://any23.org

Web site with ~5000 products description with
GoodRelations using RDFa


use Any23 in your Java
programs
Any23 runner = new Any23();
runner.setHTTPUserAgent("test-user-agent");
HTTPClient httpClient = runner.getHTTPClient();
DocumentSource source = new HTTPDocumentSource(
httpClient,
"http://test.com/index.html"
);
ByteArrayOutputStream out = new
ByteArrayOutputStream();
TripleHandler handler = new NTriplesWriter(out);
runner.extract(source, handler);
String n3 = out.toString("UTF-8");


Any23: Command-Line tool
any23-core/bin$ ./any23

usage: any23 [-e <arg>] [-f <arg>] [-l <arg>] [-n] [-o <arg>]
[-p] [-s] [-t] [-v] {<url>|<file>}
-e <arg> comma-separated list of extractors, e.g.
rdf-xml,rdf-turtle
-f,--format <arg> Output format [turtle (default),
ntriples, rdfxml, quad, uris]
-l,--log <arg> logging, please specify a file
-n,--nesting disable production of nesting triples
-o,--output <arg> ouput file (defaults to stdout)
-p,--pedantic validates and fixes HTML content
detecting commons issues
-s,--stats print out statistics of Any23


Any23: Web Service
blacky:~ davide$ curl http://any23.org/any23/?format=nquads&url=http://
www.bbc.co.uk/programmes/b00kygwh&report=on

<response>
<extractors>
<extractor>rdf-xml</extractor>
</extractors>
<report>
...
<validationReport>
<ruleActivations></ruleActivations>
...
</validationReport>
</report>
<data>
<rdf:Description rdf:about="http://www.bbc.co.uk/programmes/
b00kygwh#programme">
<rdf:type rdf:resource="http://purl.org/ontology/po/Episode"/>
<po:pid>b00kygwh</po:pid>
<dc:title>The Terminator</dc:title>
</rdf:Description>
</data>
</response>

Apache Tika
mimetype detection

Cyber Neko HTML
DOM extraction

Rule Fix
Validator

Microdata RDFa hListing hReview hCalendar hCard
Extractor Extractor

Microformat Extractors

Sesame RDF/XML NQuads JSON
Writer Writer Writer
ExtractionResult


extractor
public interface Extractor<Input> {

/**
* Executes the extractor. Will be invoked only once, extractors are
* not reusable.
*
* @param in The extractor's input
* @param documentURI The document's URI
* @param out Sink for extracted data
* @throws IOException On error while reading from the input stream
* @throws ExtractionException On other error, such as parse errors
*/
void run(Input in, URI documentURI, ExtractionResult out)
throws IOException, ExtractionException;

/**
* Returns a {@link org.deri.any23.extractor.ExtractorDescription} of
* this extractor.
*/
ExtractorDescription getDescription();

}


validate and fix
public interface Rule {

String getHRName();

boolean applyOn(
DOMDocument document,
RuleContext context,
ValidationReportBuilder validationReportBuilder
);
}

public interface Fix {

String getHRName();

void execute(Rule rule, RuleContext context, DOMDocument document);

}

void addRule(Class<? extends Rule> rule, Class<? extends Fix> fix);


plugins
@PluginImplementation
@Author(name="Michele Mostarda (mostarda@fbk.eu)")
public class HTMLScraperPlugin implements ExtractorPlugin {

private static final Logger logger =
LoggerFactory.getLogger(HTMLScraperPlugin.class);

@Init
public void init() {
logger.info("Plugin initialization.");
}

@Shutdown
public void shutdown() {
logger.info("Plugin shutdown.");
}

public ExtractorFactory getExtractorFactory() {
return HTMLScraperExtractor.factory;
}

}


roadmap
incoming 0.6.0 release
- support for Microdata
- support for CSV
- support for RDFa 1.1 prefix mechanism
- improved app configuration
- bug fixing

Apache (pre) Incubation process
- http://wiki.apache.org/incubator/Any23Proposal
- supporters and mentors (thanks guys!)
Simone Tripodi (@stripodi)
Tommaso Teofili (@tteofili)
- we’re looking for mentors


closing credits

active committers

Giovanni Tummarello ( @jccq )
Michele Mostarda ( @micmos )
Davide Palmisano ( @dpalmisano )
Richard Cyganiak ( @cygri )

thanks to the whole Semantic Web community,
especially those who tirelessly challenge us
with bugs and features requests


References

[1] http://purl.org/goodrelations/v1

[2] http://tripletalk.wordpress.com/2011/01/25/
rdfa-deployment-across-the-web/


distilling the Web of Data drop by drop (with Java)

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