Module org.apache.jena.core
Package org.apache.jena.graph

Class GraphUtil

java.lang.Object
org.apache.jena.graph.GraphUtil
public class GraphUtil extends Object
An ad-hoc collection of useful code for graphs

  • Method Details

    • listSubjects

      public static ExtendedIterator<Node> listSubjects(Graph g, Node p, Node o)
      Return an iterator over the unique subjects with predicate p and object o. p and o can be wildcards (Node.ANY)
      Parameters:
      g - Graph
      p - Predicate - may be Node.ANY
      o - Object - may be Node.ANY
      Returns:
      ExtendedIterator

    • listPredicates

      public static ExtendedIterator<Node> listPredicates(Graph g, Node s, Node o)
      Return an iterator over the unique predicate between s and o. s and o can be wildcards (Node.ANY)
      Parameters:
      g - Graph
      s - Subject - may be Node.ANY
      o - Object - may be Node.ANY
      Returns:
      ExtendedIterator

    • listObjects

      public static ExtendedIterator<Node> listObjects(Graph g, Node s, Node p)
      Return an iterator over the unique objects with a given subject and object. s and p can be wildcards (Node.ANY)
      Parameters:
      g - Graph
      s - Subject - may be Node.ANY
      p - Predicate - may be Node.ANY
      Returns:
      ExtendedIterator

    • containsNode

      public static boolean containsNode(Graph graph, Node node)
      Does the graph use the node anywhere as a subject, predicate or object?

    • findAll

      public static ExtendedIterator<Triple> findAll(Graph g)
      Answer an iterator covering all the triples in the specified graph.
      Parameters:
      g - the graph from which to extract triples
      Returns:
      an iterator over all the graph's triples

    • add

      public static void add(Graph graph, Triple[] triples)

    • add

      public static void add(Graph graph, List<Triple> triples)

    • add

      public static void add(Graph graph, Iterator<Triple> it)

    • addInto

      public static void addInto(Graph dstGraph, Graph srcGraph)
      Add triples into the destination (arg 1) from the source (arg 2)

    • delete

      public static void delete(Graph graph, Triple[] triples)

    • delete

      public static void delete(Graph graph, List<Triple> triples)

    • delete

      public static void delete(Graph graph, Iterator<Triple> it)

    • remove

      public static void remove(Graph g, Node s, Node p, Node o)
      A safe and cautious remove() function that converts the remove to a number of Graph.delete(Triple) operations.

      To avoid any possible ConcurrentModificationExceptions, it finds batches of triples, deletes them and tries again until no more triples matching the input can be found.

    • deleteLoopSrc

      public static void deleteLoopSrc(Graph dstGraph, Graph srcGraph)
      Delete triples in srcGraph from dstGraph by looping on srcGraph.

    • deleteLoopDst

      public static void deleteLoopDst(Graph dstGraph, Graph srcGraph)
      Delete the triple in srcGraph from dstGraph by checking the contents of dsgGraph against the srcGraph. This involves calling srcGraph.contains.
      Implementation Note:
      dstGraph.size() is used by this method.

    • deleteFrom

      public static void deleteFrom(Graph dstGraph, Graph srcGraph)
      Delete triples in the destination (arg 1) as given in the source (arg 2).
      Implementation Note:
      This is designed for the case of dstGraph being comparable or much larger than srcGraph or srcGraph having a lot of triples to actually be deleted from dstGraph. This includes the case of large, persistent dstGraph.

      It is not designed for a large srcGraph and large dstGraph with only a few triples in common to delete from dstGraph. It is better to calculate the difference in some way, and copy into a small graph to use as the srcGraph.

      To force delete by looping on srcGraph, use deleteLoopSrc(Graph, Graph).

      For large srcGraph and small dstGraph, use deleteLoopDst(org.apache.jena.graph.Graph, org.apache.jena.graph.Graph). See discussion on jena/pull/212, (archived at JENA-1284).