org.apache.ojb.broker.accesslayer
Class PagingIterator

java.lang.Object
  org.apache.ojb.broker.accesslayer.PagingIterator

All Implemented Interfaces:

java.util.Iterator, OJBIterator

public class PagingIterator

extends java.lang.Object

implements OJBIterator

PagingIterator is wrapper around an OJBIterator to support startAt endAt positions. The PagingIterator returns rows including startAt and including endAt. startAt = 1, endAt = 11 returns rows 1 to 11 if available if endAt == Query.NO_END_AT_INDEX endAt is set to the last available row

Version:

$Id: PagingIterator.java,v 1.8 2003/12/18 18:54:32 brj Exp $

Author:

Jakob Braeuchi

Constructor Summary

PagingIterator(OJBIterator anIterator, int startAt, int endAt)
Constructor

Method Summary

boolean	absolute(int row) Moves the cursor to the given row number in the iterator.
int	fullSize()
boolean	hasNext()
java.lang.Object	next()
boolean	relative(int row) Moves the cursor a relative number of rows, either positive or negative.
void	releaseDbResources() Release all internally used Database resources of the iterator.
void	remove() remove is not supported
int	size()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PagingIterator

public PagingIterator(OJBIterator anIterator,
                      int startAt,
                      int endAt)

Constructor

Parameters:

anIterator - wrapped Iterator

startAt - (first row is 1)

endAt - (Query.NO_END_AT_INDEX stands for all available rows)

Method Detail

size

public int size()
         throws PersistenceBrokerException

Specified by:

size in interface OJBIterator

Returns:

the size of the iterator, aka the number of rows in this iterator.

Throws:

PersistenceBrokerException

fullSize

public int fullSize()
             throws PersistenceBrokerException

Specified by:

fullSize in interface OJBIterator

Returns:

the unlimited size of the iterator, fullSize() may differ from size() for PagingIterator

Throws:

PersistenceBrokerException

absolute

public boolean absolute(int row)
                 throws PersistenceBrokerException

Description copied from interface: OJBIterator

Moves the cursor to the given row number in the iterator. If the row number is positive, the cursor moves to the given row number with respect to the beginning of the iterator. The first row is row 1, the second is row 2, and so on.

Specified by:

absolute in interface OJBIterator

Parameters:

row - the row to move to in this iterator, by absolute number

Throws:

PersistenceBrokerException

relative

public boolean relative(int row)
                 throws PersistenceBrokerException

Description copied from interface: OJBIterator

Moves the cursor a relative number of rows, either positive or negative. Attempting to move beyond the first/last row in the iterator positions the cursor before/after the the first/last row. Calling relative(0) is valid, but does not change the cursor position.

Specified by:

relative in interface OJBIterator

Parameters:

row - the row to move to in this iterator, by relative number

Throws:

PersistenceBrokerException

releaseDbResources

public void releaseDbResources()

Description copied from interface: OJBIterator

Release all internally used Database resources of the iterator. Clients must call this methods explicitely if the iterator is not exhausted by the client application. If the Iterator is exhauseted this method will be called implicitely.

Specified by:

releaseDbResources in interface OJBIterator

remove

public void remove()

remove is not supported

Specified by:

remove in interface java.util.Iterator

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator

next

public java.lang.Object next()

Specified by:

next in interface java.util.Iterator