org.apache.commons.collections.iterators
Class ReverseListIterator
java.lang.Object
org.apache.commons.collections.iterators.ReverseListIterator
- Iterator, ListIterator, ResettableIterator, ResettableListIterator
public class ReverseListIterator
extends java.lang.Object
Iterates backwards through a List, starting with the last element
and continuing to the first. This is useful for looping around
a list in reverse order without needing to actually reverse the list.
The first call to
next()
will return the last element
from the list, and so on. The
hasNext()
method works
in concert with the
next()
method as expected.
However, the
nextIndex()
method returns the correct
index in the list, thus it starts high and reduces as the iteration
continues. The previous methods work similarly.
$Revision: $ $Date: 2006-05-12 23:52:43 +0100 (Fri, 12 May 2006) $- Serge Knystautas
- Stephen Colebourne
void | add(Object obj) - Adds a new element to the list between the next and previous elements.
|
boolean | hasNext() - Checks whether there is another element.
|
boolean | hasPrevious() - Checks whether there is a previous element.
|
Object | next() - Gets the next element.
|
int | nextIndex() - Gets the index of the next element.
|
Object | previous() - Gets the previous element.
|
int | previousIndex() - Gets the index of the previous element.
|
void | remove() - Removes the last returned element.
|
void | reset() - Resets the iterator back to the start (which is the
end of the list as this is a reversed iterator)
|
void | set(Object obj) - Replaces the last returned element.
|
ReverseListIterator
public ReverseListIterator(List list)
Constructor that wraps a list.
list
- the list to create a reversed iterator for
add
public void add(Object obj)
Adds a new element to the list between the next and previous elements.
hasNext
public boolean hasNext()
Checks whether there is another element.
- true if there is another element
hasPrevious
public boolean hasPrevious()
Checks whether there is a previous element.
- true if there is a previous element
next
public Object next()
Gets the next element.
The next element is the previous in the list.
- the next element in the iterator
nextIndex
public int nextIndex()
Gets the index of the next element.
- the index of the next element in the iterator
previous
public Object previous()
Gets the previous element.
The next element is the previous in the list.
- the previous element in the iterator
previousIndex
public int previousIndex()
Gets the index of the previous element.
- the index of the previous element in the iterator
remove
public void remove()
Removes the last returned element.
set
public void set(Object obj)
Replaces the last returned element.
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