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