Interface NodeIterator

All Superinterfaces:
ClosableIterator<RDFNode>, org.apache.jena.atlas.lib.Closeable, ExtendedIterator<RDFNode>, Iterator<RDFNode>, org.apache.jena.atlas.iterator.IteratorCloseable<RDFNode>
All Known Implementing Classes:
ContNodeIteratorImpl, NodeIteratorImpl, SeqNodeIteratorImpl

public interface NodeIterator extends ExtendedIterator<RDFNode>
An iterator which returns RDF nodes.

RDF iterators are standard Java iterators, except that they have an extra method that returns specifically typed objects, in this case RDF nodes, and have a close() method. that should be called to free resources if the application does not complete the iteration.

  • Method Details

    • hasNext

      boolean hasNext()
      Determine if there any more values in the iteration.
      Specified by:
      hasNext in interface Iterator<RDFNode>
      Returns:
      true if and only if there are more values available from the iteration.
    • next

      Return the next RDFNode of the iteration.
      Specified by:
      next in interface Iterator<RDFNode>
      Returns:
      The next RDFNode from the iteration.
      Throws:
      NoSuchElementException - if there are no more nodes to be returned.
    • nextNode

      RDFNode nextNode() throws NoSuchElementException
      Return the next RDFNode of the iteration.
      Returns:
      The next RDFNode from the iteration.
      Throws:
      NoSuchElementException - if there are no more nodes to be returned.
    • remove

      void remove() throws NoSuchElementException
      Unsupported Operation.
      Specified by:
      remove in interface Iterator<RDFNode>
      Throws:
      NoSuchElementException
    • close

      void close()
      Terminate the iteration and free up resources.

      Some implementations, e.g. on relational databases, hold resources while the iterator still exists. These will normally be freed when the iteration completes. However, if an application wishes to ensure they are freed without completing the iteration, this method should be called.

      .
      Specified by:
      close in interface ClosableIterator<RDFNode>
      Specified by:
      close in interface org.apache.jena.atlas.lib.Closeable