org.axiondb
Interface RowIterator

All Known Subinterfaces:

JoinedRowIterator, MutableIndexedRowIterator

All Known Implementing Classes:

BaseJoinedRowIterator, BaseRowIterator, ChainedRowIterator, ChangingIndexedRowIterator, DelegatingRowIterator, EmptyRowIterator, FilteringChangingIndexedRowIterator, SingleRowIterator

public interface RowIterator

A bidirectional iterator over a collection of Rows.

Version:

$Revision: 1.10 $ $Date: 2004/08/27 03:21:20 $

Method Summary

void	add(Row row) Add a Rowat the current position in my underlying collection, or throw UnsupportedOperationException.
Row	current() Returns the last Rowreturned by me (by next(),previous(), first(),last(), etc.).
int	currentIndex() Returns the index of the current()row, if any.
Row	first() Returns the first Rowin the list, positioning the cursor to just before the first Rowin the list.
boolean	hasCurrent() Returns true if I have a current Row.
boolean	hasNext() Returns true if I have more Rows when traversing the list in the forward direction.
boolean	hasPrevious() Returns true if I have more Rows when traversing the list in the reverse direction.
boolean	isEmpty() Returns true if there are no rows to report with this iterator.
Row	last() Returns the last Rowin the list, positioning the cursor to just after the last Rowin the list.
Row	next() Returns the next Rowin the list, or throws NoSuchElementExceptionif no next Row exists.
int	nextIndex() Returns the index of the next()row, if any, or the number of elements is the iterator if we've reached the end.
Row	peekNext() Return the value that would be returned by a call to next(), if any, but don't update my position.
Row	peekPrevious() Return the value that would be returned by a call to previous(), if any, but don't update my position.
Row	previous() Returns the previous Rowin the list, or throws NoSuchElementExceptionif no next Row exists.
int	previousIndex() Returns the index of the previous()row, if any, or -1 if we're add the beginning of the list.
void	remove() Set the Rowat the current position in my underlying collection, or throw UnsupportedOperationException.
void	reset() Re-initialize this RowIterator to its initial state (positioned just before the first Rowin the list).
void	set(Row row) Set the Rowat the current position in my underlying collection, or throw UnsupportedOperationException.

Method Detail

add

public void add(Row row)
         throws UnsupportedOperationException,
                AxionException

Add a Rowat the current position in my underlying collection, or throw UnsupportedOperationException. (Optional operation.)

Throws:

UnsupportedOperationException

AxionException

current

public Row current()
            throws NoSuchElementException

Returns the last Rowreturned by me (by next(),previous(), first(),last(), etc.).

Throws:

NoSuchElementException - when no Rowhas yet been returned

currentIndex

public int currentIndex()
                 throws NoSuchElementException

Returns the index of the current()row, if any.

Throws:

NoSuchElementException - when no Rowhas yet been returned

first

public Row first()
          throws NoSuchElementException,
                 AxionException

Returns the first Rowin the list, positioning the cursor to just before the first Rowin the list. (In other words, after first is called both next()and current()will return the first row in the list.)

Throws:

NoSuchElementException - when there is no first Row

AxionException - when a problem occurs accessing the Row

hasCurrent

public boolean hasCurrent()

Returns true if I have a current Row. (In other words, returns true iff current()would return a Rowrather than throwing an exception.)

hasNext

public boolean hasNext()

Returns true if I have more Rows when traversing the list in the forward direction. (In other words, returns true iff next()would return a Rowrather than throwing an exception.)

hasPrevious

public boolean hasPrevious()

Returns true if I have more Rows when traversing the list in the reverse direction. (In other words, returns true iff previous()would return a Rowrather than throwing an exception.)

isEmpty

public boolean isEmpty()

Returns true if there are no rows to report with this iterator.

last

public Row last()
         throws NoSuchElementException,
                AxionException

Returns the last Rowin the list, positioning the cursor to just after the last Rowin the list. (In other words, after last is called both previous()and current()will return the last row in the list.)

Throws:

NoSuchElementException - when there is no last Row

AxionException - when a problem occurs accessing the Row

next

public Row next()
         throws NoSuchElementException,
                AxionException

Returns the next Rowin the list, or throws NoSuchElementExceptionif no next Row exists.

Throws:

NoSuchElementException - when there is no next Row

AxionException - when a problem occurs accessing the Row

nextIndex

public int nextIndex()

Returns the index of the next()row, if any, or the number of elements is the iterator if we've reached the end.

peekNext

public Row peekNext()
             throws NoSuchElementException,
                    AxionException

Return the value that would be returned by a call to next(), if any, but don't update my position.

Throws:

NoSuchElementException - when there is no next Row

AxionException - when a problem occurs accessing the Row

peekPrevious

public Row peekPrevious()
                 throws NoSuchElementException,
                        AxionException

Return the value that would be returned by a call to previous(), if any, but don't update my position.

Throws:

NoSuchElementException - when there is no previous Row

AxionException - when a problem occurs accessing the Row

previous

public Row previous()
             throws NoSuchElementException,
                    AxionException

Returns the previous Rowin the list, or throws NoSuchElementExceptionif no next Row exists.

Throws:

NoSuchElementException - when there is no next Row

AxionException - when a problem occurs accessing the Row

previousIndex

public int previousIndex()

Returns the index of the previous()row, if any, or -1 if we're add the beginning of the list.

remove

public void remove()
            throws UnsupportedOperationException,
                   AxionException

Set the Rowat the current position in my underlying collection, or throw UnsupportedOperationException. (Optional operation.)

Throws:

UnsupportedOperationException

AxionException

reset

public void reset()
           throws AxionException

Re-initialize this RowIterator to its initial state (positioned just before the first Rowin the list).

Throws:

AxionException

set

public void set(Row row)
         throws UnsupportedOperationException,
                AxionException

Set the Rowat the current position in my underlying collection, or throw UnsupportedOperationException. (Optional operation.)

Throws:

UnsupportedOperationException

AxionException