public class

CursorableLinkedList

extends Object
implements Serializable List<E>
java.lang.Object
   ↳ org.apache.commons.collections.CursorableLinkedList

This class is deprecated.
Use new version in list subpackage, which has been rewritten and now returns the cursor from the listIterator method. Will be removed in v4.0

Class Overview

A doubly-linked list implementation of the List interface, supporting a ListIterator that allows concurrent modifications to the underlying list.

Implements all of the optional List operations, the stack/queue/dequeue operations available in java.util.LinkedList and supports a ListIterator that allows concurrent modifications to the underlying list (see cursor()).

Note that this implementation is not synchronized.

See Also
  • java.util.LinkedList

Summary

Nested Classes
class CursorableLinkedList.Cursor  
Fields
protected List _cursors A list of the currently CursorableLinkedList.Cursors currently open in this list.
protected CursorableLinkedList.Listable _head A sentry node.
protected int _modCount Tracks the number of structural modifications to me.
protected int _size The number of elements in me.
Public Constructors
CursorableLinkedList()
Public Methods
boolean add(Object o)
Appends the specified element to the end of this list.
void add(int index, Object element)
Inserts the specified element at the specified position in this list.
boolean addAll(Collection c)
Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified Collection's Iterator.
boolean addAll(int index, Collection c)
Inserts all of the elements in the specified collection into this list at the specified position.
boolean addFirst(Object o)
Inserts the specified element at the beginning of this list.
boolean addLast(Object o)
Inserts the specified element at the end of this list.
void clear()
Removes all of the elements from this list.
boolean contains(Object o)
Returns true if this list contains the specified element.
boolean containsAll(Collection c)
Returns true if this list contains all of the elements of the specified collection.
CursorableLinkedList.Cursor cursor(int i)
Returns a ListIterator for iterating through the elements of this list, initialized such that next() will return the element at the specified index (if any) and previous() will return the element immediately preceding it (if any).
CursorableLinkedList.Cursor cursor()
Returns a ListIterator for iterating through the elements of this list.
boolean equals(Object o)
Compares the specified object with this list for equality.
Object get(int index)
Returns the element at the specified position in this list.
Object getFirst()
Returns the element at the beginning of this list.
Object getLast()
Returns the element at the end of this list.
int hashCode()
Returns the hash code value for this list.
int indexOf(Object o)
Returns the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element.
boolean isEmpty()
Returns true if this list contains no elements.
Iterator iterator()
Returns a fail-fast iterator.
int lastIndexOf(Object o)
Returns the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element.
ListIterator listIterator(int index)
Returns a fail-fast ListIterator.
ListIterator listIterator()
Returns a fail-fast ListIterator.
Object remove(int index)
Removes the element at the specified position in this list (optional operation).
boolean remove(Object o)
Removes the first occurrence in this list of the specified element.
boolean removeAll(Collection c)
Removes from this list all the elements that are contained in the specified collection.
Object removeFirst()
Removes the first element of this list, if any.
Object removeLast()
Removes the last element of this list, if any.
boolean retainAll(Collection c)
Retains only the elements in this list that are contained in the specified collection.
Object set(int index, Object element)
Replaces the element at the specified position in this list with the specified element.
int size()
Returns the number of elements in this list.
List subList(int i, int j)
Returns a fail-fast sublist.
Object[] toArray(Object[] a)
Returns an array containing all of the elements in this list in proper sequence; the runtime type of the returned array is that of the specified array.
Object[] toArray()
Returns an array containing all of the elements in this list in proper sequence.
String toString()
Returns a String representation of this list, suitable for debugging.
Protected Methods
void broadcastListableChanged(CursorableLinkedList.Listable elt)
Informs all of my registered cursors that the specified element was changed.
void broadcastListableInserted(CursorableLinkedList.Listable elt)
Informs all of my registered cursors that the specified element was just added to my list.
void broadcastListableRemoved(CursorableLinkedList.Listable elt)
Informs all of my registered cursors that the specified element was just removed from my list.
CursorableLinkedList.Listable getListableAt(int index)
Returns the org.apache.commons.collections.CursorableLinkedList.Listable at the specified index.
CursorableLinkedList.Listable insertListable(CursorableLinkedList.Listable before, CursorableLinkedList.Listable after, Object value)
Inserts a new value into my list, after the specified before element, and before the specified after element
void invalidateCursors()
Informs all of my registered cursors that they are now invalid.
void registerCursor(CursorableLinkedList.Cursor cur)
Registers a CursorableLinkedList.Cursor to be notified of changes to this list.
void removeListable(CursorableLinkedList.Listable elt)
Removes the given org.apache.commons.collections.CursorableLinkedList.Listable from my list.
void unregisterCursor(CursorableLinkedList.Cursor cur)
Removes a CursorableLinkedList.Cursor from the set of cursors to be notified of changes to this list.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.lang.Iterable
From interface java.util.Collection
From interface java.util.List

Fields

protected List _cursors

A list of the currently CursorableLinkedList.Cursors currently open in this list.

protected CursorableLinkedList.Listable _head

A sentry node.

_head.next() points to the first element in the list, _head.prev() to the last. Note that it is possible for _head.next().prev() and _head.prev().next() to be non-null, as when I am a sublist for some larger list. Use == _head.next() and == _head.prev() to determine if a given org.apache.commons.collections.CursorableLinkedList.Listable is the first or last element in the list.

protected int _modCount

Tracks the number of structural modifications to me.

protected int _size

The number of elements in me.

Public Constructors

public CursorableLinkedList ()

Public Methods

public boolean add (Object o)

Appends the specified element to the end of this list.

Parameters
o element to be appended to this list.
Returns
  • true

public void add (int index, Object element)

Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

Parameters
index index at which the specified element is to be inserted.
element element to be inserted.
Throws
ClassCastException if the class of the specified element prevents it from being added to this list.
IllegalArgumentException if some aspect of the specified element prevents it from being added to this list.
IndexOutOfBoundsException if the index is out of range (index < 0 || index > size()).

public boolean addAll (Collection c)

Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified Collection's Iterator. The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.)

Parameters
c collection whose elements are to be added to this list.
Returns
  • true if this list changed as a result of the call.
Throws
ClassCastException if the class of an element in the specified collection prevents it from being added to this list.
IllegalArgumentException if some aspect of an element in the specified collection prevents it from being added to this list.

public boolean addAll (int index, Collection c)

Inserts all of the elements in the specified collection into this list at the specified position. Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices). The new elements will appear in this list in the order that they are returned by the specified Collection's Iterator. The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.)

Parameters
index index at which to insert first element from the specified collection.
c elements to be inserted into this list.
Returns
  • true if this list changed as a result of the call.
Throws
ClassCastException if the class of one of elements of the specified collection prevents it from being added to this list.
IllegalArgumentException if some aspect of one of elements of the specified collection prevents it from being added to this list.
IndexOutOfBoundsException if the index is out of range (index < 0 || index > size()).

public boolean addFirst (Object o)

Inserts the specified element at the beginning of this list. (Equivalent to add(0,o)).

Parameters
o element to be prepended to this list.
Returns
  • true

public boolean addLast (Object o)

Inserts the specified element at the end of this list. (Equivalent to add(java.lang.Object)).

Parameters
o element to be appended to this list.
Returns
  • true

public void clear ()

Removes all of the elements from this list. This list will be empty after this call returns (unless it throws an exception).

public boolean contains (Object o)

Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that (o==null ? e==null : o.equals(e)).

Parameters
o element whose presence in this list is to be tested.
Returns
  • true if this list contains the specified element.

public boolean containsAll (Collection c)

Returns true if this list contains all of the elements of the specified collection.

Parameters
c collection to be checked for containment in this list.
Returns
  • true if this list contains all of the elements of the specified collection.

public CursorableLinkedList.Cursor cursor (int i)

Returns a ListIterator for iterating through the elements of this list, initialized such that next() will return the element at the specified index (if any) and previous() will return the element immediately preceding it (if any). Unlike iterator(), a cursor is not bothered by concurrent modifications to the underlying list.

Throws
IndexOutOfBoundsException if the index is out of range (index < 0 || index > size()).
See Also

public CursorableLinkedList.Cursor cursor ()

Returns a ListIterator for iterating through the elements of this list. Unlike iterator(), a cursor is not bothered by concurrent modifications to the underlying list.

Specifically, when elements are added to the list before or after the cursor, the cursor simply picks them up automatically. When the "current" (i.e., last returned by next() or previous()) element of the list is removed, the cursor automatically adjusts to the change (invalidating the last returned value--i.e., it cannot be removed).

Note that the returned ListIterator does not support the nextIndex() and previousIndex() methods (they throw UnsupportedOperationException when invoked.

Historical Note: In previous versions of this class, the object returned from this method was required to be explicitly closed. This is no longer necessary.

See Also

public boolean equals (Object o)

Compares the specified object with this list for equality. Returns true if and only if the specified object is also a list, both lists have the same size, and all corresponding pairs of elements in the two lists are equal. (Two elements e1 and e2 are equal if (e1==null ? e2==null : e1.equals(e2)).) In other words, two lists are defined to be equal if they contain the same elements in the same order. This definition ensures that the equals method works properly across different implementations of the List interface.

Parameters
o the object to be compared for equality with this list.
Returns
  • true if the specified object is equal to this list.

public Object get (int index)

Returns the element at the specified position in this list.

Parameters
index index of element to return.
Returns
  • the element at the specified position in this list.
Throws
IndexOutOfBoundsException if the index is out of range (index < 0 || index >= size()).

public Object getFirst ()

Returns the element at the beginning of this list.

public Object getLast ()

Returns the element at the end of this list.

public int hashCode ()

Returns the hash code value for this list. The hash code of a list is defined to be the result of the following calculation: 

  hashCode = 1;
  Iterator i = list.iterator();
  while (i.hasNext()) {
      Object obj = i.next();
      hashCode = 31*hashCode + (obj==null ? 0 : obj.hashCode());
  }
This ensures that list1.equals(list2) implies that list1.hashCode()==list2.hashCode() for any two lists, list1 and list2, as required by the general contract of Object.hashCode.

Returns
  • the hash code value for this list.
See Also

public int indexOf (Object o)

Returns the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.

Parameters
o element to search for.
Returns
  • the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element.

public boolean isEmpty ()

Returns true if this list contains no elements.

Returns
  • true if this list contains no elements.

public Iterator iterator ()

Returns a fail-fast iterator.

See Also

public int lastIndexOf (Object o)

Returns the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element. More formally, returns the highest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.

Parameters
o element to search for.
Returns
  • the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element.

public ListIterator listIterator (int index)

Returns a fail-fast ListIterator.

See Also

public ListIterator listIterator ()

Returns a fail-fast ListIterator.

See Also

public Object remove (int index)

Removes the element at the specified position in this list (optional operation). Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the list.

Parameters
index the index of the element to removed.
Returns
  • the element previously at the specified position.
Throws
IndexOutOfBoundsException if the index is out of range (index < 0 || index >= size()).

public boolean remove (Object o)

Removes the first occurrence in this list of the specified element. If this list does not contain the element, it is unchanged. More formally, removes the element with the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))) (if such an element exists).

Parameters
o element to be removed from this list, if present.
Returns
  • true if this list contained the specified element.

public boolean removeAll (Collection c)

Removes from this list all the elements that are contained in the specified collection.

Parameters
c collection that defines which elements will be removed from this list.
Returns
  • true if this list changed as a result of the call.

public Object removeFirst ()

Removes the first element of this list, if any.

public Object removeLast ()

Removes the last element of this list, if any.

public boolean retainAll (Collection c)

Retains only the elements in this list that are contained in the specified collection. In other words, removes from this list all the elements that are not contained in the specified collection.

Parameters
c collection that defines which elements this set will retain.
Returns
  • true if this list changed as a result of the call.

public Object set (int index, Object element)

Replaces the element at the specified position in this list with the specified element.

Parameters
index index of element to replace.
element element to be stored at the specified position.
Returns
  • the element previously at the specified position.
Throws
ClassCastException if the class of the specified element prevents it from being added to this list.
IllegalArgumentException if some aspect of the specified element prevents it from being added to this list.
IndexOutOfBoundsException if the index is out of range (index < 0 || index >= size()).

public int size ()

Returns the number of elements in this list.

Returns
  • the number of elements in this list.

public List subList (int i, int j)

Returns a fail-fast sublist.

See Also

public Object[] toArray (Object[] a)

Returns an array containing all of the elements in this list in proper sequence; the runtime type of the returned array is that of the specified array. Obeys the general contract of the toArray() method.

Parameters
a the array into which the elements of this list are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.
Returns
  • an array containing the elements of this list.
Throws
ArrayStoreException if the runtime type of the specified array is not a supertype of the runtime type of every element in this list.

public Object[] toArray ()

Returns an array containing all of the elements in this list in proper sequence. Obeys the general contract of the toArray() method.

Returns
  • an array containing all of the elements in this list in proper sequence.

public String toString ()

Returns a String representation of this list, suitable for debugging.

Returns
  • a String representation of this list, suitable for debugging.

Protected Methods

protected void broadcastListableChanged (CursorableLinkedList.Listable elt)

Informs all of my registered cursors that the specified element was changed.

See Also

protected void broadcastListableInserted (CursorableLinkedList.Listable elt)

Informs all of my registered cursors that the specified element was just added to my list.

protected void broadcastListableRemoved (CursorableLinkedList.Listable elt)

Informs all of my registered cursors that the specified element was just removed from my list.

protected CursorableLinkedList.Listable getListableAt (int index)

Returns the org.apache.commons.collections.CursorableLinkedList.Listable at the specified index.

Throws
IndexOutOfBoundsException if index is less than zero or greater than or equal to the size of this list.

protected CursorableLinkedList.Listable insertListable (CursorableLinkedList.Listable before, CursorableLinkedList.Listable after, Object value)

Inserts a new value into my list, after the specified before element, and before the specified after element

Returns
  • the newly created org.apache.commons.collections.CursorableLinkedList.Listable

protected void invalidateCursors ()

Informs all of my registered cursors that they are now invalid.

protected void registerCursor (CursorableLinkedList.Cursor cur)

Registers a CursorableLinkedList.Cursor to be notified of changes to this list.

protected void removeListable (CursorableLinkedList.Listable elt)

Removes the given org.apache.commons.collections.CursorableLinkedList.Listable from my list.

protected void unregisterCursor (CursorableLinkedList.Cursor cur)

Removes a CursorableLinkedList.Cursor from the set of cursors to be notified of changes to this list.