public class CursorableLinkedList extends AbstractLinkedList implements Serializable
List
implementation with a ListIterator
that
allows concurrent modifications to the underlying list.
This implementation supports all of the optional List
operations.
It extends AbstractLinkedList
and thus provides the
stack/queue/dequeue operations available in LinkedList
.
The main feature of this class is the ability to modify the list and the
iterator at the same time. Both the listIterator()
and cursor()
methods provides access to a Cursor
instance which extends
ListIterator
. The cursor allows changes to the list concurrent
with changes to the iterator. Note that the iterator()
method and
sublists do not provide this cursor behaviour.
The Cursor
class is provided partly for backwards compatibility
and partly because it allows the cursor to be directly closed. Closing the
cursor is optional because references are held via a WeakReference
.
For most purposes, simply modify the iterator and list at will, and then let
the garbage collector to the rest.
Note that this implementation is not synchronized.
LinkedList
,
Serialized FormModifier and Type | Class and Description |
---|---|
static class |
CursorableLinkedList.Cursor
An extended
ListIterator that allows concurrent changes to
the underlying list. |
protected static class |
CursorableLinkedList.SubCursor
A cursor for the sublist based on LinkedSubListIterator.
|
AbstractLinkedList.LinkedListIterator, AbstractLinkedList.LinkedSubList, AbstractLinkedList.LinkedSubListIterator, AbstractLinkedList.Node
Modifier and Type | Field and Description |
---|---|
protected List |
cursors
A list of the cursor currently open on this list
|
header, modCount, size
Constructor and Description |
---|
CursorableLinkedList()
Constructor that creates.
|
CursorableLinkedList(Collection coll)
Constructor that copies the specified collection
|
Modifier and Type | Method and Description |
---|---|
protected void |
addNode(AbstractLinkedList.Node nodeToInsert,
AbstractLinkedList.Node insertBeforeNode)
Inserts a new node into the list.
|
protected void |
broadcastNodeChanged(AbstractLinkedList.Node node)
Informs all of my registered cursors that the specified
element was changed.
|
protected void |
broadcastNodeInserted(AbstractLinkedList.Node node)
Informs all of my registered cursors that the specified
element was just added to my list.
|
protected void |
broadcastNodeRemoved(AbstractLinkedList.Node node)
Informs all of my registered cursors that the specified
element was just removed from my list.
|
protected ListIterator |
createSubListListIterator(AbstractLinkedList.LinkedSubList subList,
int fromIndex)
Creates a list iterator for the sublist.
|
CursorableLinkedList.Cursor |
cursor()
Returns a
CursorableLinkedList.Cursor for iterating through the elements of this list. |
CursorableLinkedList.Cursor |
cursor(int fromIndex)
Returns a
CursorableLinkedList.Cursor for iterating through the elements of this list
starting from a specified index. |
protected void |
init()
The equivalent of a default constructor called
by any constructor and by
readObject . |
Iterator |
iterator()
Returns an iterator that does not support concurrent modification.
|
ListIterator |
listIterator()
Returns a cursor iterator that allows changes to the underlying list in parallel.
|
ListIterator |
listIterator(int fromIndex)
Returns a cursor iterator that allows changes to the underlying list in parallel.
|
protected void |
registerCursor(CursorableLinkedList.Cursor cursor)
Registers a cursor to be notified of changes to this list.
|
protected void |
removeAllNodes()
Removes all nodes by iteration.
|
protected void |
removeNode(AbstractLinkedList.Node node)
Removes the specified node from the list.
|
protected void |
unregisterCursor(CursorableLinkedList.Cursor cursor)
Deregisters a cursor from the list to be notified of changes.
|
protected void |
updateNode(AbstractLinkedList.Node node,
Object value)
Updates the node with a new value.
|
add, add, addAll, addAll, addFirst, addLast, addNodeAfter, addNodeBefore, clear, contains, containsAll, createHeaderNode, createNode, createSubListIterator, doReadObject, doWriteObject, equals, get, getFirst, getLast, getNode, hashCode, indexOf, isEmpty, isEqualValue, lastIndexOf, remove, remove, removeAll, removeFirst, removeLast, retainAll, set, size, subList, toArray, toArray, toString
protected transient List cursors
public CursorableLinkedList()
public CursorableLinkedList(Collection coll)
coll
- the collection to copyprotected void init()
readObject
.init
in class AbstractLinkedList
public Iterator iterator()
If the underlying list is modified while iterating using this iterator
a ConcurrentModificationException will occur.
The cursor behaviour is available via listIterator()
.
iterator
in interface Iterable
iterator
in interface Collection
iterator
in interface List
iterator
in class AbstractLinkedList
public ListIterator listIterator()
The cursor enables iteration and list changes to occur in any order without invalidating the iterator (from one thread). When elements are added to the list, an event is fired to all active cursors enabling them to adjust to the change in the list.
When the "current" (i.e., last returned by ListIterator.next()
or ListIterator.previous()
) element of the list is removed,
the cursor automatically adjusts to the change (invalidating the
last returned value such that it cannot be removed).
listIterator
in interface List
listIterator
in class AbstractLinkedList
public ListIterator listIterator(int fromIndex)
The cursor enables iteration and list changes to occur in any order without invalidating the iterator (from one thread). When elements are added to the list, an event is fired to all active cursors enabling them to adjust to the change in the list.
When the "current" (i.e., last returned by ListIterator.next()
or ListIterator.previous()
) element of the list is removed,
the cursor automatically adjusts to the change (invalidating the
last returned value such that it cannot be removed).
listIterator
in interface List
listIterator
in class AbstractLinkedList
fromIndex
- the index to start frompublic CursorableLinkedList.Cursor cursor()
CursorableLinkedList.Cursor
for iterating through the elements of this list.
A Cursor
is a ListIterator
with an additional
close()
method. Calling this method immediately discards the
references to the cursor. If it is not called, then the garbage collector
will still remove the reference as it is held via a WeakReference
.
The cursor enables iteration and list changes to occur in any order without invalidating the iterator (from one thread). When elements are added to the list, an event is fired to all active cursors enabling them to adjust to the change in the list.
When the "current" (i.e., last returned by ListIterator.next()
or ListIterator.previous()
) element of the list is removed,
the cursor automatically adjusts to the change (invalidating the
last returned value such that it cannot be removed).
The listIterator()
method returns the same as this method, and can
be cast to a Cursor
if the close
method is required.
public CursorableLinkedList.Cursor cursor(int fromIndex)
CursorableLinkedList.Cursor
for iterating through the elements of this list
starting from a specified index.
A Cursor
is a ListIterator
with an additional
close()
method. Calling this method immediately discards the
references to the cursor. If it is not called, then the garbage collector
will still remove the reference as it is held via a WeakReference
.
The cursor enables iteration and list changes to occur in any order without invalidating the iterator (from one thread). When elements are added to the list, an event is fired to all active cursors enabling them to adjust to the change in the list.
When the "current" (i.e., last returned by ListIterator.next()
or ListIterator.previous()
) element of the list is removed,
the cursor automatically adjusts to the change (invalidating the
last returned value such that it cannot be removed).
The listIterator(int)
method returns the same as this method, and can
be cast to a Cursor
if the close
method is required.
fromIndex
- the index to start fromIndexOutOfBoundsException
- if the index is out of range
(index < 0 || index > size()).protected void updateNode(AbstractLinkedList.Node node, Object value)
updateNode
in class AbstractLinkedList
node
- node to updatevalue
- new value of the nodeprotected void addNode(AbstractLinkedList.Node nodeToInsert, AbstractLinkedList.Node insertBeforeNode)
addNode
in class AbstractLinkedList
nodeToInsert
- new node to insertinsertBeforeNode
- node to insert beforeNullPointerException
- if either node is nullprotected void removeNode(AbstractLinkedList.Node node)
removeNode
in class AbstractLinkedList
node
- the node to removeNullPointerException
- if node
is nullprotected void removeAllNodes()
removeAllNodes
in class AbstractLinkedList
protected void registerCursor(CursorableLinkedList.Cursor cursor)
cursor
- the cursor to registerprotected void unregisterCursor(CursorableLinkedList.Cursor cursor)
cursor
- the cursor to deregisterprotected void broadcastNodeChanged(AbstractLinkedList.Node node)
node
- the node that was changedprotected void broadcastNodeRemoved(AbstractLinkedList.Node node)
node
- the node that was changedprotected void broadcastNodeInserted(AbstractLinkedList.Node node)
node
- the node that was changedprotected ListIterator createSubListListIterator(AbstractLinkedList.LinkedSubList subList, int fromIndex)
createSubListListIterator
in class AbstractLinkedList
subList
- the sublist to get an iterator forfromIndex
- the index to start from, relative to the sublistCopyright © 2001–2015 The Apache Software Foundation. All rights reserved.