public class GraphContainerUtils {
private static final Node RDFtype = RDF.type.asNode();
private static final Node BAG = RDF.Bag.asNode();
private static final Node ALT = RDF.Alt.asNode();
private static final Node SEQ = RDF.Seq.asNode();
private static final String membershipPattern = RDF.getURI() + "_(\\d+)";
private static final int NOT_FOUND = -9999;
public static Collection<Node> containerMembers(Graph graph, Node container) {
return containerMembers(graph, container, null);
}
public static Collection<Node> containerMembers(Graph graph, Node container, Node containerType) {
if (!isContainer(graph, container, containerType)) return null;
ExtendedIterator<Triple> iter = graph.find(container, Node.ANY, Node.ANY);
SortedMap<Integer, Node> triples = new TreeMap<Integer, Node>(order);
try {
for (; iter.hasNext(); ) {
Triple t = iter.next();
int index = getIndex(t);
if (index == NOT_FOUND) continue;
// Insert
triples.put(new Integer(index), t.getObject());
}
} finally {
iter.close();
}
return triples.values();
}
// List x = new ArrayList() ;
// try {
// for ( ; iter.hasNext() ; )
// {
// // Sort triples in a sorted set.
// // Then extract.
// Triple t = (Triple)iter.next() ;
// String p = t.getPredicate().getURI() ;
//
// if ( p.matches(membershipPattern) )
// x.add(t.getObject()) ;
// }
// } finally { iter.close() ; }
// return x ;
// }
public static boolean isContainerMember(
Graph graph, Node container, Node containerType, Node member) {
return countContainerMember(graph, container, containerType, member, true) != 0;
}
public static int countContainerMember(
Graph graph, Node container, Node containerType, Node member) {
return countContainerMember(graph, container, containerType, member, false);
}
private static int countContainerMember(
Graph graph, Node container, Node containerType, Node member, boolean stopEarly) {
if (graph == null) {
Log.warn(GraphContainerUtils.class, "containerMember called with null graph");
return 0;
}
if (container == null) {
Log.warn(GraphContainerUtils.class, "containerMember called with null list");
return 0;
}
if (member == null) {
Log.warn(GraphContainerUtils.class, "containerMember called with null member");
return 0;
}
if (!isContainer(graph, container, containerType)) return 0;
int count = 0;
ExtendedIterator<Triple> iter = graph.find(container, Node.ANY, member);
try {
for (; iter.hasNext(); ) {
Triple t = iter.next();
Node p = t.getPredicate();
String u = p.getURI();
if (u.matches(membershipPattern)) {
count++;
if (stopEarly) return count;
}
}
} finally {
iter.close();
}
return count;
}
// public static boolean isContainer(Graph graph, Node container)
// { return isContainer(graph, container, null) ; }
public static boolean isContainer(Graph graph, Node container, Node containerType) {
// if ( container.isLiteral() )
// return false ;
if (containerType == null)
return isContainer(graph, container, BAG)
|| isContainer(graph, container, ALT)
|| isContainer(graph, container, SEQ);
return graph.contains(container, RDFtype, containerType);
}
static Pattern pattern = Pattern.compile(membershipPattern);
private static int getIndex(Triple triple) {
String u = triple.getPredicate().getURI();
// Must be _nnn.
Matcher m = pattern.matcher(u);
if (!m.find()) return NOT_FOUND;
String index = m.group(1);
return Integer.parseInt(index);
}
static ContainerOrder order = new ContainerOrder();
private static class ContainerOrder implements java.util.Comparator<Integer> {
public int compare(Integer i1, Integer i2) {
int index1 = i1.intValue();
int index2 = i2.intValue();
if (index1 < index2) return Expr.CMP_LESS;
if (index1 > index2) return Expr.CMP_GREATER;
return Expr.CMP_EQUAL;
}
}
}
public alt() {
super(RDF.Alt.asNode());
}