info.aduna.iteration

Interface Iteration<E,X extends Exception>

Type Parameters:

E - Object type of objects contained in the iteration.

X - Exception type that is thrown when a problem occurs during iteration.

All Known Subinterfaces:

CloseableIteration<E,X>, GraphQueryResult, QueryResult<T>, TupleQueryResult

All Known Implementing Classes:

CloseableIterationBase, CloseableIteratorIteration, ConvertingIteration, DelayedIteration, DistinctIteration, EmptyIteration, ExceptionConvertingIteration, FilterIteration, GraphQueryResultImpl, IntersectIteration, IterationWrapper, IteratorIteration, LimitIteration, LookAheadIteration, MinusIteration, MutableTupleQueryResult, OffsetIteration, ReducedIteration, SingletonIteration, TimeLimitIteration, TupleQueryResultImpl, UnionIteration

public interface Iteration<E,X extends Exception>

An Iteration is a typed Iterator-like object that can throw (typed) Exceptions while iterating. This is used in cases where the iteration is lazy and evaluates over a (remote) connection, for example accessing a database. In such cases an error can occur at any time and needs to be communicated through a checked exception, something Iterator can not do (it can only throw RuntimeExceptions.

Author:

jeen, Herko ter Horst

See Also:

Iterator

Method Summary

Methods

Modifier and Type	Method and Description
boolean	hasNext() Returns true if the iteration has more elements.
E	next() Returns the next element in the iteration.
void	remove() Removes from the underlying collection the last element returned by the iteration (optional operation).

Method Detail

hasNext

boolean hasNext()
                throws X extends Exception

Returns true if the iteration has more elements. (In other words, returns true if next() would return an element rather than throwing a NoSuchElementException.)

Returns:

true if the iteration has more elements.

Throws:

X

X extends Exception

next

E next()
       throws X extends Exception

Returns the next element in the iteration.

Returns:

the next element in the iteration.

Throws:

NoSuchElementException - if the iteration has no more elements or if it has been closed.

X extends Exception

remove

void remove()
            throws X extends Exception

Removes from the underlying collection the last element returned by the iteration (optional operation). This method can be called only once per call to next.

Throws:

UnsupportedOperationException - if the remove operation is not supported by this Iteration.

IllegalStateException - If the Iteration has been closed, or if next() has not yet been called, or remove() has already been called after the last call to next().

X extends Exception