Class DescribeIteration
- java.lang.Object
-
- org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E>
-
- org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet>
-
- org.eclipse.rdf4j.query.algebra.evaluation.iterator.DescribeIteration
-
- All Implemented Interfaces:
AutoCloseable
,Iterator<BindingSet>
,CloseableIteration<BindingSet>
- Direct Known Subclasses:
FederatedDescribeIteration
public class DescribeIteration extends LookAheadIteration<BindingSet>
Iteration that implements a simplified version of Symmetric Concise Bounded Description (omitting reified statements).- Author:
- Jeen Broekstra
- See Also:
- Concise Bounded Description - alternatives
-
-
Field Summary
Fields Modifier and Type Field Description protected BindingSet
parentBindings
protected static String
VARNAME_OBJECT
protected static String
VARNAME_PREDICATE
protected static String
VARNAME_SUBJECT
-
Constructor Summary
Constructors Constructor Description DescribeIteration(CloseableIteration<BindingSet> sourceIter, EvaluationStrategy strategy, Set<String> describeExprNames, BindingSet parentBindings)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected CloseableIteration<BindingSet>
createNextIteration(Value subject, Value object)
protected BindingSet
getNextElement()
Gets the next element.protected void
handleClose()
Called byAbstractCloseableIteration.close()
when it is called for the first time.-
Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration
hasNext, next, remove
-
Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration
close, isClosed
-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
-
Methods inherited from interface org.eclipse.rdf4j.common.iteration.CloseableIteration
stream
-
Methods inherited from interface java.util.Iterator
forEachRemaining
-
-
-
-
Field Detail
-
VARNAME_SUBJECT
protected static final String VARNAME_SUBJECT
- See Also:
- Constant Field Values
-
VARNAME_PREDICATE
protected static final String VARNAME_PREDICATE
- See Also:
- Constant Field Values
-
VARNAME_OBJECT
protected static final String VARNAME_OBJECT
- See Also:
- Constant Field Values
-
parentBindings
protected BindingSet parentBindings
-
-
Constructor Detail
-
DescribeIteration
public DescribeIteration(CloseableIteration<BindingSet> sourceIter, EvaluationStrategy strategy, Set<String> describeExprNames, BindingSet parentBindings)
-
-
Method Detail
-
getNextElement
protected BindingSet getNextElement() throws QueryEvaluationException
Description copied from class:LookAheadIteration
Gets the next element. Subclasses should implement this method so that it returns the next element.- Specified by:
getNextElement
in classLookAheadIteration<BindingSet>
- Returns:
- The next element, or null if no more elements are available.
- Throws:
QueryEvaluationException
-
createNextIteration
protected CloseableIteration<BindingSet> createNextIteration(Value subject, Value object) throws QueryEvaluationException
- Throws:
QueryEvaluationException
-
handleClose
protected void handleClose() throws QueryEvaluationException
Description copied from class:AbstractCloseableIteration
Called byAbstractCloseableIteration.close()
when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.- Specified by:
handleClose
in classAbstractCloseableIteration<BindingSet>
- Throws:
QueryEvaluationException
-
-