Package org.apache.commons.collections.list

Class AbstractLinkedList

java.lang.Object
org.apache.commons.collections.list.AbstractLinkedList
All Implemented Interfaces:
Iterable, Collection, List
Direct Known Subclasses:
CursorableLinkedList, NodeCachingLinkedList
public abstract class AbstractLinkedList extends Object implements List
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:
Commons Collections 3.0
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Rich Dougherty, Phil Steitz, Stephen Colebourne

  • Field Details

    • size

      protected transient int size
      The size of the list

    • modCount

      protected transient int modCount
      Modification count for iterators

  • Constructor Details

    • 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 coll)
      Constructs a list copying data from the specified collection.
      Parameters:
      coll - the collection to copy

  • Method Details

    • 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
      Specified by:
      size in interface List

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface Collection
      Specified by:
      isEmpty in interface List

    • get

      public Object get(int index)
      Specified by:
      get in interface List

    • iterator

      public Iterator iterator()
      Specified by:
      iterator in interface Collection
      Specified by:
      iterator in interface Iterable
      Specified by:
      iterator in interface List

    • listIterator

      public ListIterator listIterator()
      Specified by:
      listIterator in interface List

    • listIterator

      public ListIterator listIterator(int fromIndex)
      Specified by:
      listIterator in interface List

    • indexOf

      public int indexOf(Object value)
      Specified by:
      indexOf in interface List

    • lastIndexOf

      public int lastIndexOf(Object value)
      Specified by:
      lastIndexOf in interface List

    • contains

      public boolean contains(Object value)
      Specified by:
      contains in interface Collection
      Specified by:
      contains in interface List

    • containsAll

      public boolean containsAll(Collection coll)
      Specified by:
      containsAll in interface Collection
      Specified by:
      containsAll in interface List

    • toArray

      public Object[] toArray()
      Specified by:
      toArray in interface Collection
      Specified by:
      toArray in interface List

    • toArray

      public Object[] toArray(Object[] array)
      Specified by:
      toArray in interface Collection
      Specified by:
      toArray in interface List

    • subList

      public List subList(int fromIndexInclusive, int toIndexExclusive)
      Gets a sublist of the main list.
      Specified by:
      subList in interface List
      Parameters:
      fromIndexInclusive - the index to start from
      toIndexExclusive - the index to end at
      Returns:
      the new sublist

    • add

      public boolean add(Object value)
      Specified by:
      add in interface Collection
      Specified by:
      add in interface List

    • add

      public void add(int index, Object value)
      Specified by:
      add in interface List

    • addAll

      public boolean addAll(Collection coll)
      Specified by:
      addAll in interface Collection
      Specified by:
      addAll in interface List

    • addAll

      public boolean addAll(int index, Collection coll)
      Specified by:
      addAll in interface List

    • remove

      public Object remove(int index)
      Specified by:
      remove in interface List

    • remove

      public boolean remove(Object value)
      Specified by:
      remove in interface Collection
      Specified by:
      remove in interface List

    • removeAll

      public boolean removeAll(Collection coll)
      Specified by:
      removeAll in interface Collection
      Specified by:
      removeAll in interface List

    • retainAll

      public boolean retainAll(Collection coll)
      Specified by:
      retainAll in interface Collection
      Specified by:
      retainAll in interface List

    • set

      public Object set(int index, Object value)
      Specified by:
      set in interface List

    • clear

      public void clear()
      Specified by:
      clear in interface Collection
      Specified by:
      clear in interface List

    • getFirst

      public Object getFirst()

    • getLast

      public Object getLast()

    • addFirst

      public boolean addFirst(Object o)

    • addLast

      public boolean addLast(Object o)

    • removeFirst

      public Object removeFirst()

    • removeLast

      public Object removeLast()

    • equals

      public boolean equals(Object obj)
      Specified by:
      equals in interface Collection
      Specified by:
      equals in interface List
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface Collection
      Specified by:
      hashCode in interface List
      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 node, Object 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 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 createNode(Object 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

    • addNodeBefore

      protected void addNodeBefore(AbstractLinkedList.Node node, Object 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 node, Object 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 nodeToInsert, AbstractLinkedList.Node 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 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 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
      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 createSubListIterator(AbstractLinkedList.LinkedSubList subList)
      Creates an iterator for the sublist.
      Parameters:
      subList - the sublist to get an iterator for

    • createSubListListIterator

      protected ListIterator createSubListListIterator(AbstractLinkedList.LinkedSubList 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

    • 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.

      Throws:
      IOException

    • 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.

      Throws:
      IOException
      ClassNotFoundException