private static List<Resource> equivalentTypes(Resource type) {
   List<Resource> types = new ArrayList<Resource>();
   types.add(type);
   for (StmtIterator it = type.getModel().listStatements(ANY, OWL.equivalentClass, type);
       it.hasNext(); ) types.add(it.nextStatement().getSubject());
   return types;
 }
Beispiel #2
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  /**
   * Answer the shortest path from the <code>start</code> resource to the <code>end</code> RDF node,
   * such that every step on the path is accepted by the given filter. A path is a {@link List} of
   * RDF {@link Statement}s. The subject of the first statement in the list is <code>start</code>,
   * and the object of the last statement in the list is <code>end</code>.
   *
   * <p>The <code>onPath</code> argument is a {@link Filter}, which accepts a statement and returns
   * true if the statement should be considered to be on the path. To search for an unconstrained
   * path, pass {@link Filter#any} as an argument. To search for a path whose predicates match a
   * fixed restricted set of property names, pass an instance of {@link PredicatesFilter}.
   *
   * <p>If there is more than one path of minimal length from <code>start</code> to <code>end</code>
   * , this method returns an arbitrary one. The algorithm is blind breadth-first search, with loop
   * detection.
   *
   * @param m The model in which we are seeking a path
   * @param start The starting resource
   * @param end The end, or goal, node
   * @param onPath A filter which determines whether a given statement can be considered part of the
   *     path
   * @return A path, consisting of a list of statements whose first subject is <code>start</code>,
   *     and whose last object is <code>end</code>, or null if no such path exists.
   */
  public static Path findShortestPath(
      Model m, Resource start, RDFNode end, Filter<Statement> onPath) {
    List<Path> bfs = new LinkedList<Path>();
    Set<Resource> seen = new HashSet<Resource>();

    // initialise the paths
    for (Iterator<Statement> i = m.listStatements(start, null, (RDFNode) null).filterKeep(onPath);
        i.hasNext(); ) {
      bfs.add(new Path().append(i.next()));
    }

    // search
    Path solution = null;
    while (solution == null && !bfs.isEmpty()) {
      Path candidate = bfs.remove(0);

      if (candidate.hasTerminus(end)) {
        solution = candidate;
      } else {
        Resource terminus = candidate.getTerminalResource();
        if (terminus != null) {
          seen.add(terminus);

          // breadth-first expansion
          for (Iterator<Statement> i = terminus.listProperties().filterKeep(onPath);
              i.hasNext(); ) {
            Statement link = i.next();

            // no looping allowed, so we skip this link if it takes us to a node we've seen
            if (!seen.contains(link.getObject())) {
              bfs.add(candidate.append(link));
            }
          }
        }
      }
    }

    return solution;
  }
 public Collection<URI> getSupportedFacets(URI needUri) throws NoSuchNeedException {
   List<URI> ret = new LinkedList<URI>();
   Need need = DataAccessUtils.loadNeed(needRepository, needUri);
   Model content = rdfStorageService.loadContent(need);
   if (content == null) return ret;
   Resource baseRes = content.getResource(content.getNsPrefixURI(""));
   StmtIterator stmtIterator = baseRes.listProperties(WON.HAS_FACET);
   while (stmtIterator.hasNext()) {
     RDFNode object = stmtIterator.nextStatement().getObject();
     if (object.isURIResource()) {
       ret.add(URI.create(object.toString()));
     }
   }
   return ret;
 }
Beispiel #4
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  private static ResultSetRewindable unique(ResultSetRewindable results) {
    // VERY crude.  Utilises the fact that bindings have value equality.
    List<Binding> x = new ArrayList<Binding>();
    Set<Binding> seen = new HashSet<Binding>();

    for (; results.hasNext(); ) {
      Binding b = results.nextBinding();
      if (seen.contains(b)) continue;
      seen.add(b);
      x.add(b);
    }
    QueryIterator qIter = new QueryIterPlainWrapper(x.iterator());
    ResultSet rs =
        new ResultSetStream(results.getResultVars(), ModelFactory.createDefaultModel(), qIter);
    return ResultSetFactory.makeRewindable(rs);
  }
Beispiel #5
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  private ResultSetRewindable convertToStrings(ResultSetRewindable resultsActual) {
    List<Binding> bindings = new ArrayList<Binding>();
    while (resultsActual.hasNext()) {
      Binding b = resultsActual.nextBinding();
      BindingMap b2 = BindingFactory.create();

      for (String vn : resultsActual.getResultVars()) {
        Var v = Var.alloc(vn);
        Node n = b.get(v);
        String s;
        if (n == null) s = "";
        else if (n.isBlank()) s = "_:" + n.getBlankNodeLabel();
        else s = NodeFunctions.str(n);
        b2.add(v, NodeFactory.createLiteral(s));
      }
      bindings.add(b2);
    }
    ResultSet rs =
        new ResultSetStream(
            resultsActual.getResultVars(), null, new QueryIterPlainWrapper(bindings.iterator()));
    return ResultSetFactory.makeRewindable(rs);
  }