68a462b05a
* [VIVO-1312] Linked Data Fragments initial implementation * [VIVO-1312] Use known ontologies in the prefixes config * [VIVO-1312] Simplify SPARQL as when restricted to specific values, they don’t need ordering * [VIVO-1312] Freemarker fixes * [VIVO-1312] Remove blank nodes * [VIVO-1312] Add access control header and standard prefixes for TPF * [VIVO-1312] Render literals in form so that they will work on resubmit * [VIVO-1312] Minor template update * [VIVO-1312] Minor template update
80 lines
2.6 KiB
Java
80 lines
2.6 KiB
Java
package org.linkeddatafragments.util;
|
|
|
|
import org.linkeddatafragments.fragments.tpf.ITriplePatternElement;
|
|
import org.linkeddatafragments.fragments.tpf.TriplePatternElementFactory;
|
|
|
|
/**
|
|
* Parses strings (as obtained from HTTP request parameters) into
|
|
* {@link ITriplePatternElement}s.
|
|
*
|
|
* @param <ConstantTermType> type for representing constants in triple patterns
|
|
* (i.e., URIs and literals)
|
|
* @param <NamedVarType> type for representing named variables in triple patterns
|
|
* @param <AnonVarType> type for representing anonymous variables in triple
|
|
* patterns (i.e., variables denoted by a blank node)
|
|
*
|
|
* @author <a href="http://olafhartig.de">Olaf Hartig</a>
|
|
* @author Ruben Verborgh
|
|
*/
|
|
abstract public
|
|
class TriplePatternElementParser<ConstantTermType,NamedVarType,AnonVarType>
|
|
extends RDFTermParser<ConstantTermType>
|
|
{
|
|
|
|
/**
|
|
*
|
|
*/
|
|
public final TriplePatternElementFactory<ConstantTermType,NamedVarType,AnonVarType>
|
|
factory = new TriplePatternElementFactory<ConstantTermType,NamedVarType,AnonVarType>();
|
|
|
|
/**
|
|
*
|
|
* @param param
|
|
* @return
|
|
*/
|
|
public ITriplePatternElement<ConstantTermType,NamedVarType,AnonVarType>
|
|
parseIntoTriplePatternElement( final String param )
|
|
{
|
|
// nothing or empty indicates an unspecified variable
|
|
if ( param == null || param.isEmpty() )
|
|
return factory.createUnspecifiedVariable();
|
|
|
|
// identify the kind of RDF term based on the first character
|
|
char firstChar = param.charAt(0);
|
|
switch ( firstChar )
|
|
{
|
|
// specific variable that has a name
|
|
case '?':
|
|
{
|
|
final String varName = param.substring(1);
|
|
final NamedVarType var = createNamedVariable( varName );
|
|
return factory.createNamedVariable( var );
|
|
}
|
|
|
|
// specific variable that is denoted by a blank node
|
|
case '_':
|
|
{
|
|
final AnonVarType var = createAnonymousVariable( param );
|
|
return factory.createAnonymousVariable( var );
|
|
}
|
|
|
|
// assume it is an RDF term
|
|
default:
|
|
return factory.createConstantRDFTerm( parseIntoRDFNode(param) );
|
|
}
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param varName
|
|
* @return
|
|
*/
|
|
abstract public NamedVarType createNamedVariable( final String varName );
|
|
|
|
/**
|
|
*
|
|
* @param label
|
|
* @return
|
|
*/
|
|
abstract public AnonVarType createAnonymousVariable( final String label );
|
|
}
|