AbstractLinkedList (Apache Commons Collections 4.2 API)

java.lang.Object
- org.apache.commons.collections4.list.AbstractLinkedList<E>

All Implemented Interfaces:

Iterable<E>, Collection<E>, List<E>

Direct Known Subclasses:

CursorableLinkedList, NodeCachingLinkedList
```
public abstract class AbstractLinkedList<E>
extends Object
implements List<E>
```
An abstract implementation of a linked list which provides numerous points for subclasses to override.
Overridable methods are provided to change the storage node and to change how nodes are added to and removed. Hopefully, all you need for unusual subclasses is here.

Since:

3.0

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`AbstractLinkedList.LinkedListIterator<E>` A list iterator over the linked list.
`protected static class`	`AbstractLinkedList.LinkedSubList<E>` The sublist implementation for AbstractLinkedList.
`protected static class`	`AbstractLinkedList.LinkedSubListIterator<E>` A list iterator over the linked sub list.
`protected static class`	`AbstractLinkedList.Node<E>` A node within the linked list.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractLinkedList()` Constructor that does nothing intended for deserialization.
`protected`	`AbstractLinkedList(Collection<? extends E> coll)` Constructs a list copying data from the specified collection.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(E value)`
`void`	`add(int index, E value)`
`boolean`	`addAll(Collection<? extends E> coll)`
`boolean`	`addAll(int index, Collection<? extends E> coll)`
`boolean`	`addFirst(E o)`
`boolean`	`addLast(E o)`
`protected void`	`addNode(AbstractLinkedList.Node<E> nodeToInsert, AbstractLinkedList.Node<E> insertBeforeNode)` Inserts a new node into the list.
`protected void`	`addNodeAfter(AbstractLinkedList.Node<E> node, E value)` Creates a new node with the specified object as its `value` and inserts it after `node`.
`protected void`	`addNodeBefore(AbstractLinkedList.Node<E> node, E value)` Creates a new node with the specified object as its `value` and inserts it before `node`.
`void`	`clear()`
`boolean`	`contains(Object value)`
`boolean`	`containsAll(Collection<?> coll)`
`protected AbstractLinkedList.Node<E>`	`createHeaderNode()` Creates a new node with previous, next and element all set to null.
`protected AbstractLinkedList.Node<E>`	`createNode(E value)` Creates a new node with the specified properties.
`protected Iterator<E>`	`createSubListIterator(AbstractLinkedList.LinkedSubList<E> subList)` Creates an iterator for the sublist.
`protected ListIterator<E>`	`createSubListListIterator(AbstractLinkedList.LinkedSubList<E> subList, int fromIndex)` Creates a list iterator for the sublist.
`protected void`	`doReadObject(ObjectInputStream inputStream)` Deserializes the data held in this object to the stream specified.
`protected void`	`doWriteObject(ObjectOutputStream outputStream)` Serializes the data held in this object to the stream specified.
`boolean`	`equals(Object obj)`
`E`	`get(int index)`
`E`	`getFirst()`
`E`	`getLast()`
`protected AbstractLinkedList.Node<E>`	`getNode(int index, boolean endMarkerAllowed)` Gets the node at a particular index.
`int`	`hashCode()`
`int`	`indexOf(Object value)`
`protected void`	`init()` The equivalent of a default constructor, broken out so it can be called by any constructor and by `readObject`.
`boolean`	`isEmpty()`
`protected boolean`	`isEqualValue(Object value1, Object value2)` Compares two values for equals.
`Iterator<E>`	`iterator()`
`int`	`lastIndexOf(Object value)`
`ListIterator<E>`	`listIterator()`
`ListIterator<E>`	`listIterator(int fromIndex)`
`E`	`remove(int index)`
`boolean`	`remove(Object value)`
`boolean`	`removeAll(Collection<?> coll)`
`protected void`	`removeAllNodes()` Removes all nodes by resetting the circular list marker.
`E`	`removeFirst()`
`E`	`removeLast()`
`protected void`	`removeNode(AbstractLinkedList.Node<E> node)` Removes the specified node from the list.
`boolean`	`retainAll(Collection<?> coll)`
`E`	`set(int index, E value)`
`int`	`size()`
`List<E>`	`subList(int fromIndexInclusive, int toIndexExclusive)` Gets a sublist of the main list.
`Object[]`	`toArray()`
`<T> T[]`	`toArray(T[] array)`
`String`	`toString()`
`protected void`	`updateNode(AbstractLinkedList.Node<E> node, E value)` Updates the node with a new value.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List
replaceAll, sort, spliterator

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable
forEach

- Constructor Detail
  - AbstractLinkedList
```
protected AbstractLinkedList()
```
    Constructor that does nothing intended for deserialization.
    If this constructor is used by a serializable subclass then the init() method must be called.
  - AbstractLinkedList
```
protected AbstractLinkedList(Collection<? extends E> coll)
```
    Constructs a list copying data from the specified collection.
    
    Parameters:
    
    coll - the collection to copy
- Method Detail
  - init
```
protected void init()
```
    The equivalent of a default constructor, broken out so it can be called by any constructor and by readObject. Subclasses which override this method should make sure they call super, so the list is initialised properly.
  - size
```
public int size()
```
    Specified by:
    
    size in interface Collection<E>
    
    Specified by:
    
    size in interface List<E>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Collection<E>
    
    Specified by:
    
    isEmpty in interface List<E>
  - get
```
public E get(int index)
```
    Specified by:
    
    get in interface List<E>
  - iterator
```
public Iterator<E> iterator()
```
    Specified by:
    
    iterator in interface Iterable<E>
    
    Specified by:
    
    iterator in interface Collection<E>
    
    Specified by:
    
    iterator in interface List<E>
  - listIterator
```
public ListIterator<E> listIterator()
```
    Specified by:
    
    listIterator in interface List<E>
  - listIterator
```
public ListIterator<E> listIterator(int fromIndex)
```
    Specified by:
    
    listIterator in interface List<E>
  - indexOf
```
public int indexOf(Object value)
```
    Specified by:
    
    indexOf in interface List<E>
  - lastIndexOf
```
public int lastIndexOf(Object value)
```
    Specified by:
    
    lastIndexOf in interface List<E>
  - contains
```
public boolean contains(Object value)
```
    Specified by:
    
    contains in interface Collection<E>
    
    Specified by:
    
    contains in interface List<E>
  - containsAll
```
public boolean containsAll(Collection<?> coll)
```
    Specified by:
    
    containsAll in interface Collection<E>
    
    Specified by:
    
    containsAll in interface List<E>
  - toArray
```
public Object[] toArray()
```
    Specified by:
    
    toArray in interface Collection<E>
    
    Specified by:
    
    toArray in interface List<E>
  - toArray
```
public <T> T[] toArray(T[] array)
```
    Specified by:
    
    toArray in interface Collection<E>
    
    Specified by:
    
    toArray in interface List<E>
  - subList
```
public List<E> subList(int fromIndexInclusive,
                       int toIndexExclusive)
```
    Gets a sublist of the main list.
    
    Specified by:
    
    subList in interface List<E>
    
    Parameters:
    
    fromIndexInclusive - the index to start from
    
    toIndexExclusive - the index to end at
    
    Returns:
    
    the new sublist
  - add
```
public boolean add(E value)
```
    Specified by:
    
    add in interface Collection<E>
    
    Specified by:
    
    add in interface List<E>
  - add
```
public void add(int index,
                E value)
```
    Specified by:
    
    add in interface List<E>
  - addAll
```
public boolean addAll(Collection<? extends E> coll)
```
    Specified by:
    
    addAll in interface Collection<E>
    
    Specified by:
    
    addAll in interface List<E>
  - addAll
```
public boolean addAll(int index,
                      Collection<? extends E> coll)
```
    Specified by:
    
    addAll in interface List<E>
  - remove
```
public E remove(int index)
```
    Specified by:
    
    remove in interface List<E>
  - remove
```
public boolean remove(Object value)
```
    Specified by:
    
    remove in interface Collection<E>
    
    Specified by:
    
    remove in interface List<E>
  - removeAll
```
public boolean removeAll(Collection<?> coll)
```
    This implementation iterates over the elements of this list, checking each element in turn to see if it's contained in coll. If it's contained, it's removed from this list. As a consequence, it is advised to use a collection type for coll that provides a fast (e.g. O(1)) implementation of Collection.contains(Object).
    
    Specified by:
    
    removeAll in interface Collection<E>
    
    Specified by:
    
    removeAll in interface List<E>
  - retainAll
```
public boolean retainAll(Collection<?> coll)
```
    This implementation iterates over the elements of this list, checking each element in turn to see if it's contained in coll. If it's not contained, it's removed from this list. As a consequence, it is advised to use a collection type for coll that provides a fast (e.g. O(1)) implementation of Collection.contains(Object).
    
    Specified by:
    
    retainAll in interface Collection<E>
    
    Specified by:
    
    retainAll in interface List<E>
  - set
```
public E set(int index,
             E value)
```
    Specified by:
    
    set in interface List<E>
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Collection<E>
    
    Specified by:
    
    clear in interface List<E>
  - getFirst
```
public E getFirst()
```
  - getLast
```
public E getLast()
```
  - addFirst
```
public boolean addFirst(E o)
```
  - addLast
```
public boolean addLast(E o)
```
  - removeFirst
```
public E removeFirst()
```
  - removeLast
```
public E removeLast()
```
  - equals
```
public boolean equals(Object obj)
```
    Specified by:
    
    equals in interface Collection<E>
    
    Specified by:
    
    equals in interface List<E>
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Collection<E>
    
    Specified by:
    
    hashCode in interface List<E>
    
    Overrides:
    
    hashCode in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - isEqualValue
```
protected boolean isEqualValue(Object value1,
                               Object value2)
```
    Compares two values for equals. This implementation uses the equals method. Subclasses can override this to match differently.
    
    Parameters:
    
    value1 - the first value to compare, may be null
    
    value2 - the second value to compare, may be null
    
    Returns:
    
    true if equal
  - updateNode
```
protected void updateNode(AbstractLinkedList.Node<E> node,
                          E value)
```
    Updates the node with a new value. This implementation sets the value on the node. Subclasses can override this to record the change.
    
    Parameters:
    
    node - node to update
    
    value - new value of the node
  - createHeaderNode
```
protected AbstractLinkedList.Node<E> createHeaderNode()
```
    Creates a new node with previous, next and element all set to null. This implementation creates a new empty Node. Subclasses can override this to create a different class.
    
    Returns:
    
    newly created node
  - createNode
```
protected AbstractLinkedList.Node<E> createNode(E value)
```
    Creates a new node with the specified properties. This implementation creates a new Node with data. Subclasses can override this to create a different class.
    
    Parameters:
    
    value - value of the new node
    
    Returns:
    
    a new node containing the value
  - addNodeBefore
```
protected void addNodeBefore(AbstractLinkedList.Node<E> node,
                             E value)
```
    Creates a new node with the specified object as its value and inserts it before node.
    This implementation uses createNode(Object) and addNode(AbstractLinkedList.Node,AbstractLinkedList.Node).
    
    Parameters:
    
    node - node to insert before
    
    value - value of the newly added node
    
    Throws:
    
    NullPointerException - if node is null
  - addNodeAfter
```
protected void addNodeAfter(AbstractLinkedList.Node<E> node,
                            E value)
```
    Creates a new node with the specified object as its value and inserts it after node.
    This implementation uses createNode(Object) and addNode(AbstractLinkedList.Node,AbstractLinkedList.Node).
    
    Parameters:
    
    node - node to insert after
    
    value - value of the newly added node
    
    Throws:
    
    NullPointerException - if node is null
  - addNode
```
protected void addNode(AbstractLinkedList.Node<E> nodeToInsert,
                       AbstractLinkedList.Node<E> insertBeforeNode)
```
    Inserts a new node into the list.
    
    Parameters:
    
    nodeToInsert - new node to insert
    
    insertBeforeNode - node to insert before
    
    Throws:
    
    NullPointerException - if either node is null
  - removeNode
```
protected void removeNode(AbstractLinkedList.Node<E> node)
```
    Removes the specified node from the list.
    
    Parameters:
    
    node - the node to remove
    
    Throws:
    
    NullPointerException - if node is null
  - removeAllNodes
```
protected void removeAllNodes()
```
    Removes all nodes by resetting the circular list marker.
  - getNode
```
protected AbstractLinkedList.Node<E> getNode(int index,
                                             boolean endMarkerAllowed)
                                      throws IndexOutOfBoundsException
```
    Gets the node at a particular index.
    
    Parameters:
    
    index - the index, starting from 0
    
    endMarkerAllowed - whether or not the end marker can be returned if startIndex is set to the list's size
    
    Returns:
    
    the node at the given index
    
    Throws:
    
    IndexOutOfBoundsException - if the index is less than 0; equal to the size of the list and endMakerAllowed is false; or greater than the size of the list
  - createSubListIterator
```
protected Iterator<E> createSubListIterator(AbstractLinkedList.LinkedSubList<E> subList)
```
    Creates an iterator for the sublist.
    
    Parameters:
    
    subList - the sublist to get an iterator for
    
    Returns:
    
    a new iterator on the given sublist
  - createSubListListIterator
```
protected ListIterator<E> createSubListListIterator(AbstractLinkedList.LinkedSubList<E> subList,
                                                    int fromIndex)
```
    Creates a list iterator for the sublist.
    
    Parameters:
    
    subList - the sublist to get an iterator for
    
    fromIndex - the index to start from, relative to the sublist
    
    Returns:
    
    a new list iterator on the given sublist
  - doWriteObject
```
protected void doWriteObject(ObjectOutputStream outputStream)
                      throws IOException
```
    Serializes the data held in this object to the stream specified.
    The first serializable subclass must call this method from writeObject.
    
    Parameters:
    
    outputStream - the stream to write the object to
    
    Throws:
    
    IOException - if anything goes wrong
  - doReadObject
```
protected void doReadObject(ObjectInputStream inputStream)
                     throws IOException,
                            ClassNotFoundException
```
    Deserializes the data held in this object to the stream specified.
    The first serializable subclass must call this method from readObject.
    
    Parameters:
    
    inputStream - the stream to read the object from
    
    Throws:
    
    IOException - if any error occurs while reading from the stream
    
    ClassNotFoundException - if a class read from the stream can not be loaded

Class AbstractLinkedList<E>

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.List

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Constructor Detail

AbstractLinkedList

AbstractLinkedList

Method Detail

init

size

isEmpty

get

iterator

listIterator

listIterator

indexOf

lastIndexOf

contains

containsAll

toArray

toArray

subList

add

add

addAll

addAll

remove

remove

removeAll

retainAll

set

clear

getFirst

getLast

addFirst

addLast

removeFirst

removeLast

equals

hashCode

toString

isEqualValue

updateNode

createHeaderNode

createNode

addNodeBefore

addNodeAfter

addNode

removeNode

removeAllNodes

getNode

createSubListIterator

createSubListListIterator

doWriteObject

doReadObject