private static boolean matchNode(Item node, Item item, Match details) {
if (isAny(item)) {
details.anyMatches++;
return true;
}
if (isAnyVar(item)) {
details.varMatches++;
return true;
}
if (node.isSymbol()) {
// TERM in the thing to be matched means something concrete will be there.
if (node.equals(TERM)) {
if (item.equals(TERM)) {
details.termMatches++;
return true;
}
// Does not match LITERAL, URI, BNODE and VAR/ANY were done above.
return false;
}
throw new ARQException("StatsMatcher: unexpected slot type: " + node);
}
if (!node.isNode()) return false;
Node n = node.getNode();
if (n.isConcrete()) {
if (item.isNode() && item.getNode().equals(n)) {
details.exactMatches++;
return true;
}
if (isAnyTerm(item)) {
details.termMatches++;
return true;
}
if (isAnyURI(item) && n.isURI()) {
details.termMatches++;
return true;
}
if (isAnyLiteral(item) && n.isLiteral()) {
details.termMatches++;
return true;
}
if (isAnyBNode(item) && n.isBlank()) {
details.termMatches++;
return true;
}
}
return false;
}
protected Object extractBinding(Map<String, Node> binds, int nodeIndex) {
Node node = this.nodes[nodeIndex];
if (node.isVariable()) {
Node boundNode = binds.get(this.nodes[nodeIndex].getName());
if (boundNode == null) {
throw new UnsupportedOperationException("Unbound variable");
}
node = boundNode;
}
if (node.isConcrete()) {
Node_Concrete lit = (Node_Concrete) node;
if (lit.isLiteral()) return lit.getLiteralValue();
else if (lit.isURI()) return lit.getURI();
else if (lit.isBlank()) return lit.getBlankNodeLabel();
}
throw new UnsupportedOperationException("Incorrect node type for comparison: " + node);
}
/**
* Builds up statements like [] rr:template "http://data.example.com/department/{DEPTNO}" or []
* rr:class ex:Department and returns them as a Statement List.
*
* @param r2rml the target com.hp.hpl.jena.rdf.model.Model
* @param mappingData the target that should be mapped to relational structures (subject,
* predicate or object)
* @param varDefs the construction definition of the target value based in the actual database
* value and some additional data like prefix strings or certain functions like uri( ... )
* @return a List<Statement> containing all the subject map statements
*/
private List<Statement> buildMapStatements(Model r2rml, Node mappingData, VarDefinition varDefs) {
List<Statement> results = new ArrayList<Statement>();
// a blank node []
Resource mapSubject = ResourceFactory.createResource();
// rr:template or rr:column or rr:constant
Property mapPredicate;
// a literal like "http://data.example.com/department/{DEPTNO}" or
// simply "DEPTNO" (column name) or a constant "Foo bar!!"
// (or in rare cases a URI, which is handled separately)
Literal mapObject;
// template or column or constant
if (mappingData.isVariable()) {
Collection<RestrictedExpr> restrictions = varDefs.getDefinitions((Var) mappingData);
List<PredicateAndObject> mapPredicateAndObjects = processRestrictions(restrictions);
for (PredicateAndObject result : mapPredicateAndObjects) {
mapPredicate = result.getPrediacte();
Statement resultStatement;
RDFNode rawObject = result.getRawObject();
// object is literal
if (rawObject.isLiteral()) {
mapObject = rawObject.asLiteral();
resultStatement = r2rml.createStatement(mapSubject, mapPredicate, mapObject);
// object is blank node
} else if (rawObject.isAnon()) {
Resource mapResObject = rawObject.asResource();
resultStatement = r2rml.createStatement(mapSubject, mapPredicate, mapResObject);
// object is resource
} else {
Resource mapResObject = rawObject.asResource();
resultStatement = r2rml.createStatement(mapSubject, mapPredicate, mapResObject);
}
results.add(resultStatement);
}
// everything that is not a variable is handled as a constant
} else if (mappingData.isConcrete()) {
// URIs and Literals have to be handled separately since the methods
// to retrieve the respective value are different
Statement resultStatement;
// URI
if (mappingData.isURI()) {
/*
* This case is somewhat special since the mapObject is not a
* Literal. So, this needs some special handling:
* - the Literal mapObject will not be used
* - a special mapObject_uri Resource will be created
* - the result will be created, appended to the List and
* returned to not go through any further ordinary processing
*/
Resource mapObject_uri = ResourceFactory.createResource(mappingData.getURI());
mapPredicate = ResourceFactory.createProperty(rrNamespace, "constant");
resultStatement = r2rml.createStatement(mapSubject, mapPredicate, mapObject_uri);
results.add(resultStatement);
return results;
// Literal
} else if (mappingData.isLiteral()) {
mapObject = ResourceFactory.createPlainLiteral(mappingData.getLiteral().toString(false));
// else (e.g. blank node)
} else { // mapSubject.isBlank() == true
/*
* Hmm... I think this violates the standard. So lean back and
* enjoy the trace...
*/
mapObject = null;
}
mapPredicate = ResourceFactory.createProperty(rrPrefix, "constant");
resultStatement = r2rml.createStatement(mapSubject, mapPredicate, mapObject);
results.add(resultStatement);
}
return results;
}
