org.jboss.util.collection

Class CachedList

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList

org.jboss.util.collection.CachedList

All Implemented Interfaces:

java.lang.Iterable, java.util.Collection, java.util.List

public class CachedList
extends java.util.AbstractList

A wrapper around a List which translates added objects into SoftObject references, allowing the VM to garbage collect objects in the collection when memory is low.

Version:

$Revision$

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.List	list Wrapped list.
protected java.lang.ref.ReferenceQueue	queue Reference queue.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
CachedList() Construct a CachedList using a LinkedList for storage.
CachedList(java.util.List list) Construct a CachedList.

Method Summary

Modifier and Type	Method and Description
void	add(int index, java.lang.Object obj) Inserts the specified element at the specified position in this list (optional operation).
java.lang.Object	get(int index) Returns the element at the specified position in this list.
private java.lang.Object	getObject(int index) Dereference the object at the given index.
private void	maintain() Maintains the collection by removing garbage collected objects.
java.lang.Object	remove(int index) Removes the element at the specified position in this list (optional operation).
java.lang.Object	set(int index, java.lang.Object obj) Replaces the element at the specified position in this list with the specified element.
int	size() Return the size of the list.

Methods inherited from class java.util.AbstractList

add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

queue

protected final java.lang.ref.ReferenceQueue queue

Reference queue.

list

protected final java.util.List list

Wrapped list.

Constructor Detail

CachedList

public CachedList(java.util.List list)

Construct a CachedList.

Parameters:

list - List to wrap.

CachedList

public CachedList()

Construct a CachedList using a LinkedList for storage.

Method Detail

getObject

private java.lang.Object getObject(int index)

Dereference the object at the given index.

get

public java.lang.Object get(int index)

Returns the element at the specified position in this list.

Specified by:

get in interface java.util.List

Specified by:

get in class java.util.AbstractList

Parameters:

index - Index of element to return.

Returns:

The element at the specified position.

size

public int size()

Return the size of the list.

Specified by:

size in interface java.util.Collection

Specified by:

size in interface java.util.List

Specified by:

size in class java.util.AbstractCollection

Returns:

The number of elements in the list.

set

public java.lang.Object set(int index,
                            java.lang.Object obj)

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

Specified by:

set in interface java.util.List

Overrides:

set in class java.util.AbstractList

Parameters:

index - Index of element to replace.

obj - Element to be stored at the specified postion.

Returns:

The previous element at the given index.

add

public void add(int index,
                java.lang.Object obj)

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

Specified by:

add in interface java.util.List

Overrides:

add in class java.util.AbstractList

Parameters:

index - Index at which the specified element is to be inserted.

obj - Element to be inserted.

remove

public java.lang.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.

Specified by:

remove in interface java.util.List

Overrides:

remove in class java.util.AbstractList

Parameters:

index - The index of the element to remove.

Returns:

The element previously at the specified position.

maintain

private void maintain()

Maintains the collection by removing garbage collected objects.