Package org.apache.commons.rdf.api

Interface Dataset

    • Method Summary

      All Methods Instance Methods Abstract Methods Default Methods 
      Modifier and Type Method Description
      void add​(BlankNodeOrIRI graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
      Add a quad to the dataset, possibly mapping any of the components to those supported by this dataset.
      void add​(Quad quad)
      Add a quad to the dataset, possibly mapping any of the components of the Quad to those supported by this dataset.
      void clear()
      Clear the dataset, removing all quads.
      default void close()
      Close the dataset, relinquishing any underlying resources.
      boolean contains​(java.util.Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
      Check if dataset contains a pattern of quads.
      boolean contains​(Quad quad)
      Check if dataset contains quad.
      Graph getGraph()
      Get the default graph of this dataset.
      java.util.Optional<Graph> getGraph​(BlankNodeOrIRI graphName)
      Get a named graph in this dataset.
      java.util.stream.Stream<BlankNodeOrIRI> getGraphNames()
      Get the graph names in this Dataset.
      default java.lang.Iterable<Quad> iterate()
      Get an Iterable for iterating over all quads in the dataset.
      default java.lang.Iterable<Quad> iterate​(java.util.Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
      Get an Iterable for iterating over the quads in the dataset that match the pattern.
      void remove​(java.util.Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
      Remove a concrete pattern of quads from the default graph of the dataset.
      void remove​(Quad quad)
      Remove a concrete quad from the dataset.
      long size()
      Number of quads contained by the dataset.
      java.util.stream.Stream<? extends Quad> stream()
      Get all quads contained by the dataset.
      java.util.stream.Stream<? extends Quad> stream​(java.util.Optional<BlankNodeOrIRI> graphName, BlankNodeOrIRI subject, IRI predicate, RDFTerm object)
      Get all quads contained by the dataset matched with the pattern.

    • Method Detail

      • add

        void add​(Quad quad)
        Add a quad to the dataset, possibly mapping any of the components of the Quad to those supported by this dataset.
        Specified by:
        add in interface GraphLike<Quad>
        Parameters:
        quad - The quad to add

      • add

        void add​(BlankNodeOrIRI graphName,
         BlankNodeOrIRI subject,
         IRI predicate,
         RDFTerm object)
        Add a quad to the dataset, possibly mapping any of the components to those supported by this dataset.
        Parameters:
        graphName - The graph the quad belongs to, or null for the default graph
        subject - The quad subject
        predicate - The quad predicate
        object - The quad object

      • contains

        boolean contains​(Quad quad)
        Check if dataset contains quad.
        Specified by:
        contains in interface GraphLike<Quad>
        Parameters:
        quad - The quad to check.
        Returns:
        True if the dataset contains the given Quad.

      • contains

        boolean contains​(java.util.Optional<BlankNodeOrIRI> graphName,
                 BlankNodeOrIRI subject,
                 IRI predicate,
                 RDFTerm object)
        Check if dataset contains a pattern of quads.
        Parameters:
        graphName - The graph the quad belongs to, wrapped as an Optional (null is a wildcard, Optional.empty() is the default graph)
        subject - The quad subject (null is a wildcard)
        predicate - The quad predicate (null is a wildcard)
        object - The quad object (null is a wildcard)
        Returns:
        True if the dataset contains any quads that match the given pattern.

      • close

        default void close()
            throws java.lang.Exception
        Close the dataset, relinquishing any underlying resources.

        For example, this would close any open file and network streams and free database locks held by the dataset implementation.

        The behaviour of the other dataset methods are undefined after closing the dataset.

        Implementations might not need close(), hence the default implementation does nothing.

        Specified by:
        close in interface java.lang.AutoCloseable
        Throws:
        java.lang.Exception

      • getGraph

        Graph getGraph()
        Get the default graph of this dataset.

        The Triples of the default graph are equivalent to the Quads in this Dataset which has the Quad.getGraphName() set to Optional.empty().

        It is unspecified if modifications to the returned Graph are reflected in this Dataset.

        The returned graph MAY be empty.

        Returns:
        The default graph of this Dataset
        See Also:
        getGraph(BlankNodeOrIRI)

      • getGraph

        java.util.Optional<Graph> getGraph​(BlankNodeOrIRI graphName)
        Get a named graph in this dataset.

        The Triples of the named graph are equivalent to the the Quads of this Dataset which has the Quad.getGraphName() equal to the provided graphName, or equal to Optional.empty() if the provided graphName is null.

        It is unspecified if modifications to the returned Graph are reflected in this Dataset.

        It is unspecified if requesting an unknown or empty graph will return Optional.empty() or create a new empty Graph.

        Parameters:
        graphName - The name of the graph, or null for the default graph.
        Returns:
        The named Graph, or Optional.empty() if the dataset do not contain the named graph.
        See Also:
        getGraph(), getGraphNames()

      • getGraphNames

        java.util.stream.Stream<BlankNodeOrIRI> getGraphNames()
        Get the graph names in this Dataset.

        The set of returned graph names is equivalent to the set of unique Quad.getGraphName() of all the stream() of this dataset (excluding the default graph).

        The returned Stream SHOULD NOT contain duplicate graph names.

        The graph names can be used with getGraph(BlankNodeOrIRI) to retrieve the corresponding Graph, however callers should be aware of any concurrent modifications to the Dataset may cause such calls to return Optional.empty().

        Note that a Dataset always contains a default graph which is not named, and thus is not represented in the returned Stream. The default graph is accessible via getGraph() or by using Optional.empty() in the Quad access methods).

        Returns:
        A Stream of the graph names of this Dataset.

      • remove

        void remove​(Quad quad)
        Remove a concrete quad from the dataset.
        Specified by:
        remove in interface GraphLike<Quad>
        Parameters:
        quad - quad to remove

      • remove

        void remove​(java.util.Optional<BlankNodeOrIRI> graphName,
            BlankNodeOrIRI subject,
            IRI predicate,
            RDFTerm object)
        Remove a concrete pattern of quads from the default graph of the dataset.
        Parameters:
        graphName - The graph the quad belongs to, wrapped as an Optional (null is a wildcard, Optional.empty() is the default graph)
        subject - The quad subject (null is a wildcard)
        predicate - The quad predicate (null is a wildcard)
        object - The quad object (null is a wildcard)

      • clear

        void clear()
        Clear the dataset, removing all quads.
        Specified by:
        clear in interface GraphLike<Quad>

      • size

        long size()
        Number of quads contained by the dataset.

        The count of a set does not include duplicates, consistent with the Quad.equals(Object) equals method for each Quad.

        Specified by:
        size in interface GraphLike<Quad>
        Returns:
        The number of quads in the dataset

      • stream

        java.util.stream.Stream<? extends Quad> stream()
        Get all quads contained by the dataset.

        The iteration does not contain any duplicate quads, as determined by the Quad.equals(Object) method for each Quad.

        The behaviour of the Stream is not specified if add(Quad), remove(Quad) or clear() are called on the Dataset before it terminates.

        Implementations may throw ConcurrentModificationException from Stream methods if they detect a conflict while the Stream is active.

        Specified by:
        stream in interface GraphLike<Quad>
        Returns:
        A Stream over all of the quads in the dataset

      • stream

        java.util.stream.Stream<? extends Quad> stream​(java.util.Optional<BlankNodeOrIRI> graphName,
                                               BlankNodeOrIRI subject,
                                               IRI predicate,
                                               RDFTerm object)
        Get all quads contained by the dataset matched with the pattern.

        The iteration does not contain any duplicate quads, as determined by the Quad.equals(Object) method for each Quad.

        The behaviour of the Stream is not specified if add(Quad), remove(Quad) or clear() are called on the Dataset before it terminates.

        Implementations may throw ConcurrentModificationException from Stream methods if they detect a conflict while the Stream is active.

        Parameters:
        graphName - The graph the quad belongs to, wrapped as an Optional (null is a wildcard, Optional.empty() is the default graph)
        subject - The quad subject (null is a wildcard)
        predicate - The quad predicate (null is a wildcard)
        object - The quad object (null is a wildcard)
        Returns:
        A Stream over the matched quads.

      • iterate

        default java.lang.Iterable<Quad> iterate()
                                  throws java.util.ConcurrentModificationException,
                                         java.lang.IllegalStateException
        Get an Iterable for iterating over all quads in the dataset.

        This method is meant to be used with a Java for-each loop, e.g.: 

         for (Quad t : dataset.iterate()) {
     System.out.println(t);
 }
        The behaviour of the iterator is not specified if add(Quad), remove(Quad) or clear(), are called on the Dataset before it terminates. It is undefined if the returned Iterator supports the Iterator.remove() method.

        Implementations may throw ConcurrentModificationException from Iterator methods if they detect a concurrency conflict while the Iterator is active.

        The Iterable.iterator() must only be called once, that is the Iterable must only be iterated over once. A IllegalStateException may be thrown on attempt to reuse the Iterable.

        The default implementation of this method will call stream() to return its BaseStream.iterator().

        Specified by:
        iterate in interface GraphLike<Quad>
        Returns:
        A Iterable that returns Iterator over all of the quads in the dataset
        Throws:
        java.lang.IllegalStateException - if the Iterable has been reused
        java.util.ConcurrentModificationException - if a concurrency conflict occurs while the Iterator is active.

      • iterate

        default java.lang.Iterable<Quad> iterate​(java.util.Optional<BlankNodeOrIRI> graphName,
                                         BlankNodeOrIRI subject,
                                         IRI predicate,
                                         RDFTerm object)
                                  throws java.util.ConcurrentModificationException,
                                         java.lang.IllegalStateException
        Get an Iterable for iterating over the quads in the dataset that match the pattern.

        This method is meant to be used with a Java for-each loop, e.g.: 

         IRI alice = factory.createIRI("http://example.com/alice");
 IRI knows = factory.createIRI("http://xmlns.com/foaf/0.1/");
 for (Quad t : dataset.iterate(null, alice, knows, null)) {
     System.out.println(t.getGraphName());
     System.out.println(t.getObject());
 }

        The behaviour of the iterator is not specified if add(Quad), remove(Quad) or clear(), are called on the Dataset before it terminates. It is undefined if the returned Iterator supports the Iterator.remove() method.

        Implementations may throw ConcurrentModificationException from Iterator methods if they detect a concurrency conflict while the Iterator is active.

        The Iterable.iterator() must only be called once, that is the Iterable must only be iterated over once. A IllegalStateException may be thrown on attempt to reuse the Iterable.

        The default implementation of this method will call stream(Optional, BlankNodeOrIRI, IRI, RDFTerm) to return its BaseStream.iterator().

        Parameters:
        graphName - The graph the quad belongs to, wrapped as an Optional (null is a wildcard, Optional.empty() is the default graph)
        subject - The quad subject (null is a wildcard)
        predicate - The quad predicate (null is a wildcard)
        object - The quad object (null is a wildcard)
        Returns:
        A Iterable that returns Iterator over the matching quads in the dataset
        Throws:
        java.lang.IllegalStateException - if the Iterable has been reused
        java.util.ConcurrentModificationException - if a concurrency conflict occurs while the Iterator is active.