com.persistit

Class PersistitMap.ExchangeIterator<E>

java.lang.Object

com.persistit.PersistitMap.ExchangeIterator<E>

All Implemented Interfaces:

Iterator<E>

Enclosing class:

PersistitMap<K,V>

public abstract class PersistitMap.ExchangeIterator<E>
extends Object
implements Iterator<E>

Implements java.util.Iterator using an underlying Persistit tree as the source of keys and values to be traversed. In addition to the inherited methods of java.util.Iterator, this class also implements a facility to apply a KeyFilter to restrict the set of keys over it will iterate. See setFilterTerm(KeyFilter.Term) and getKeyFilter() for details.

Method Summary

Modifier and Type	Method and Description
Key.Direction	getDirection()
KeyFilter	getKeyFilter() Returns the KeyFilter for this iterator, or null if there is none.
boolean	hasNext()
protected void	nextEntry()
void	remove()
void	setDirection(Key.Direction direction) Set the desired traversal direction of this Iterator.
void	setFilterTerm(KeyFilter.Term term) Set up a KeyFilter for this Iterator.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, next

Method Detail

setDirection

public void setDirection(Key.Direction direction)

Set the desired traversal direction of this Iterator. Values Key.GT (ascending) and Key.LT (descending) are allowed.

Parameters:

direction - The direction

getDirection

public Key.Direction getDirection()

Returns:

The traversal direction (GT for increasing keys, LT for decreasing keys) of this Iterator.

getKeyFilter

public KeyFilter getKeyFilter()

Returns the KeyFilter for this iterator, or null if there is none.

Returns:

A copy of the current KeyFilter, or null if there is none.

setFilterTerm

public void setFilterTerm(KeyFilter.Term term)

Set up a KeyFilter for this Iterator. When set, the hasNext() and Iterator.next() operations return only those keys, values or entries for records having keys selected by the supplied KeyFilter.Term. Note that setting the filter affects subsequent hasNext or next operations, but does not modify the current key, nor does it affect the behavior of remove() or PersistitMap.ExchangeEntry.setValue(V) for the current entry.

Parameters:

term - If null, clears the KeyFilter for this iterator. Otherwise, sets up a filter based on the supplied Term.

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

nextEntry

protected void nextEntry()

remove

public void remove()

Specified by:

remove in interface Iterator<E>