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Jena is a Java framework for building Semantic Web applications. It provides a programmatic environment for RDF, RDFS and OWL, SPARQL and includes a rule-based inference engine.
/*
(c) Copyright 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
All rights reserved - see end of file.
$Id: QueryTriple.java,v 1.11 2008/01/02 12:07:57 andy_seaborne Exp $
*/
package com.hp.hpl.jena.graph.query;
import java.util.*;
import com.hp.hpl.jena.graph.*;
import com.hp.hpl.jena.shared.BrokenException;
/**
A QueryTriple is a composite of three QueryNodes derived from a
single source triple. QueryTriple knows how to classify a triple
into a QueryTriple based on the classification of that triple's elements.
A QueryTriple can create a specific Matcher which
will do the minimal amount of work to match triples that have been
generated by find on the finder of that QueryTriple.
@author hedgehog
*/
public class QueryTriple
{
public final QueryNode S;
public final QueryNode P;
public final QueryNode O;
public QueryTriple( QueryNode S, QueryNode P, QueryNode O )
{ this.S = S; this.P = P; this.O = O; }
public String toString()
{ return ""; }
public static QueryTriple [] classify( QueryNodeFactory f, Mapping m, Triple [] t )
{
QueryTriple [] result = f.createArray( t.length );
for (int i = 0; i < t.length; i += 1) result[i] = classify( f, m, t[i] );
return result;
}
public static QueryTriple classify( QueryNodeFactory f, Mapping m, Triple t )
{
HashSet fresh = new HashSet();
return f.createTriple
( QueryNode.classify( f, m, fresh, t.getSubject() ),
QueryNode.classify( f, m, fresh, t.getPredicate() ),
QueryNode.classify( f, m, fresh, t.getObject() ) );
}
public Applyer createApplyer( final Graph g )
{ return new SimpleApplyer( g, this ); }
public Matcher createMatcher()
{
final int SMATCH = 4, PMATCH = 2, OMATCH = 1, NOMATCH = 0;
int bits =
(S.mustMatch() ? SMATCH : 0)
+ (P.mustMatch() ? PMATCH : 0)
+ (O.mustMatch() ? OMATCH : 0)
;
switch (bits)
{
case SMATCH + PMATCH + OMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{ return S.match( d, t.getSubject() )
&& P.match( d, t.getPredicate() )
&& O.match( d, t.getObject() ); }
};
case SMATCH + OMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{
return S.match( d, t.getSubject() )
&& O.match( d, t.getObject() ); }
};
case SMATCH + PMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{
return S.match( d, t.getSubject() )
&& P.match( d, t.getPredicate() );
}
};
case PMATCH + OMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{
return P.match( d, t.getPredicate() )
&& O.match( d, t.getObject() );
}
};
case SMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{ return S.match( d, t.getSubject() ); }
};
case PMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{ return P.match( d, t.getPredicate() ); }
};
case OMATCH:
return new Matcher()
{
public boolean match( Domain d, Triple t )
{ return O.match( d, t.getObject() ); }
};
case NOMATCH:
return Matcher.always;
}
throw new BrokenException( "uncatered-for case in optimisation" );
}
public static class SimpleApplyer extends Applyer
{
protected final Graph g;
protected final QueryNode s;
protected final QueryNode p;
protected final QueryNode o;
protected SimpleApplyer( Graph g, QueryTriple qt )
{ this.g = g; this.o = qt.O; this.p = qt.P; this.s = qt.S; }
public Iterator find( Domain d )
{ return g.find( s.finder( d ), p.finder( d ), o.finder( d ) ); }
public void applyToTriples( Domain d, Matcher m, StageElement next )
{
Iterator it = find( d );
while (it.hasNext())
if (m.match( d, (Triple) it.next() ))
next.run( d );
}
}
}
/*
* (c) Copyright 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/