Class SingletonListIterator
- java.lang.Object
-
- org.apache.commons.collections.iterators.SingletonListIterator
-
- All Implemented Interfaces:
Iterator
,ListIterator
,ResettableIterator
,ResettableListIterator
public class SingletonListIterator extends Object implements ListIterator, ResettableListIterator
SingletonIterator
is anListIterator
over a single object instance.- Since:
- Commons Collections 2.1
- Version:
- $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
- Author:
- Stephen Colebourne, Rodney Waldhoff
-
-
Constructor Summary
Constructors Constructor Description SingletonListIterator(Object object)
Constructs a newSingletonListIterator
.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
add(Object obj)
Add always throwsUnsupportedOperationException
.boolean
hasNext()
Is another object available from the iterator?boolean
hasPrevious()
Is a previous object available from the iterator?Object
next()
Get the next object from the iterator.int
nextIndex()
Returns the index of the element that would be returned by a subsequent call to next.Object
previous()
Get the previous object from the iterator.int
previousIndex()
Returns the index of the element that would be returned by a subsequent call to previous.void
remove()
Remove the object from this iterator.void
reset()
Reset the iterator back to the start.void
set(Object obj)
Set sets the value of the singleton.-
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
-
-
-
-
Constructor Detail
-
SingletonListIterator
public SingletonListIterator(Object object)
Constructs a newSingletonListIterator
.- Parameters:
object
- the single object to return from the iterator
-
-
Method Detail
-
hasNext
public boolean hasNext()
Is another object available from the iterator?This returns true if the single object hasn't been returned yet.
- Specified by:
hasNext
in interfaceIterator
- Specified by:
hasNext
in interfaceListIterator
- Returns:
- true if the single object hasn't been returned yet
-
hasPrevious
public boolean hasPrevious()
Is a previous object available from the iterator?This returns true if the single object has been returned.
- Specified by:
hasPrevious
in interfaceListIterator
- Returns:
- true if the single object has been returned
-
nextIndex
public int nextIndex()
Returns the index of the element that would be returned by a subsequent call to next.- Specified by:
nextIndex
in interfaceListIterator
- Returns:
- 0 or 1 depending on current state.
-
previousIndex
public int previousIndex()
Returns the index of the element that would be returned by a subsequent call to previous. A return value of -1 indicates that the iterator is currently at the start.- Specified by:
previousIndex
in interfaceListIterator
- Returns:
- 0 or -1 depending on current state.
-
next
public Object next()
Get the next object from the iterator.This returns the single object if it hasn't been returned yet.
- Specified by:
next
in interfaceIterator
- Specified by:
next
in interfaceListIterator
- Returns:
- the single object
- Throws:
NoSuchElementException
- if the single object has already been returned
-
previous
public Object previous()
Get the previous object from the iterator.This returns the single object if it has been returned.
- Specified by:
previous
in interfaceListIterator
- Returns:
- the single object
- Throws:
NoSuchElementException
- if the single object has not already been returned
-
remove
public void remove()
Remove the object from this iterator.- Specified by:
remove
in interfaceIterator
- Specified by:
remove
in interfaceListIterator
- Throws:
IllegalStateException
- if the next or previous method has not yet been called, or the remove method has already been called after the last call to next or previous.
-
add
public void add(Object obj)
Add always throwsUnsupportedOperationException
.- Specified by:
add
in interfaceListIterator
- Throws:
UnsupportedOperationException
- always
-
set
public void set(Object obj)
Set sets the value of the singleton.- Specified by:
set
in interfaceListIterator
- Parameters:
obj
- the object to set- Throws:
IllegalStateException
- if next has not been called or the object has been removed
-
reset
public void reset()
Reset the iterator back to the start.- Specified by:
reset
in interfaceResettableIterator
- Specified by:
reset
in interfaceResettableListIterator
-
-