Class SingletonListIterator<E>
java.lang.Object
org.apache.commons.collections4.iterators.SingletonListIterator<E>
- All Implemented Interfaces:
Iterator<E>
,ListIterator<E>
,OrderedIterator<E>
,ResettableIterator<E>
,ResettableListIterator<E>
SingletonIterator
is an ListIterator
over a single
object instance.- Since:
- 2.1
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Add always throwsUnsupportedOperationException
.boolean
hasNext()
Is another object available from the iterator?boolean
Is a previous object available from the iterator?next()
Get the next object from the iterator.int
Returns the index of the element that would be returned by a subsequent call tonext
.previous()
Get the previous object from the iterator.int
Returns the index of the element that would be returned by a subsequent call toprevious
.void
remove()
Remove the object from this iterator.void
reset()
Reset the iterator back to the start.void
Set sets the value of the singleton.
-
Constructor Details
-
SingletonListIterator
Constructs a newSingletonListIterator
.- Parameters:
object
- the single object to return from the iterator
-
-
Method Details
-
hasNext
Is another object available from the iterator?This returns true if the single object hasn't been returned yet.
-
hasPrevious
Is a previous object available from the iterator?This returns true if the single object has been returned.
- Specified by:
hasPrevious
in interfaceListIterator<E>
- Specified by:
hasPrevious
in interfaceOrderedIterator<E>
- Returns:
- true if the single object has been returned
-
nextIndex
Returns the index of the element that would be returned by a subsequent call tonext
.- Specified by:
nextIndex
in interfaceListIterator<E>
- Returns:
- 0 or 1 depending on current state.
-
previousIndex
Returns the index of the element that would be returned by a subsequent call toprevious
. A return value of -1 indicates that the iterator is currently at the start.- Specified by:
previousIndex
in interfaceListIterator<E>
- Returns:
- 0 or -1 depending on current state.
-
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<E>
- Specified by:
next
in interfaceListIterator<E>
- Returns:
- the single object
- Throws:
NoSuchElementException
- if the single object has already been returned
-
previous
Get the previous object from the iterator.This returns the single object if it has been returned.
- Specified by:
previous
in interfaceListIterator<E>
- Specified by:
previous
in interfaceOrderedIterator<E>
- Returns:
- the single object
- Throws:
NoSuchElementException
- if the single object has not already been returned
-
remove
Remove the object from this iterator.- Specified by:
remove
in interfaceIterator<E>
- Specified by:
remove
in interfaceListIterator<E>
- Throws:
IllegalStateException
- if thenext
orprevious
method has not yet been called, or theremove
method has already been called after the last call tonext
orprevious
.
-
add
Add always throwsUnsupportedOperationException
.- Specified by:
add
in interfaceListIterator<E>
- Parameters:
obj
- the object to add- Throws:
UnsupportedOperationException
- always
-
set
Set sets the value of the singleton.- Specified by:
set
in interfaceListIterator<E>
- Parameters:
obj
- the object to set- Throws:
IllegalStateException
- ifnext
has not been called or the object has been removed
-
reset
Reset the iterator back to the start.- Specified by:
reset
in interfaceResettableIterator<E>
-