org.datanucleus.store.query

Class AbstractLazyLoadList<E>

java.lang.Object

org.datanucleus.store.query.AbstractLazyLoadList<E>

Type Parameters:

E - Type of the element of this list

All Implemented Interfaces:

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

Direct Known Subclasses:

AbstractCandidateLazyLoadList

public abstract class AbstractLazyLoadList<E>
extends Object
implements List<E>

Abstract implementation of a lazy loaded list of (persistent) objects. Needs to be extended to implement the

retrieveObjectForIndex()

method to retrieve the object at the specified index from whatever datasource is being used, and to implement the

getSize()

method to return the size of the list. The "datasource" could be results for a query, or a connection to a datastore, or whatever ... just a source of objects. TODO Change Localised message numbers to be generic

Field Summary

Fields

Modifier and Type	Field and Description
protected int	size Cached size of the list.

Constructor Summary

Constructors

Constructor and Description
AbstractLazyLoadList(String cacheType) Constructor for a lazy load list.

Method Summary

Modifier and Type	Method and Description
void	add(int index, Object element)
boolean	add(Object e)
boolean	addAll(Collection c)
boolean	addAll(int index, Collection c)
void	clear()
boolean	contains(Object o)
boolean	containsAll(Collection c)
E	get(int index)
protected abstract int	getSize() Method to return the size of the list.
int	indexOf(Object o)
boolean	isEmpty()
protected boolean	isOpen() Accessor whether the list is open.
Iterator<E>	iterator()
int	lastIndexOf(Object o)
ListIterator	listIterator()
ListIterator	listIterator(int index)
E	remove(int index)
boolean	remove(Object o)
boolean	removeAll(Collection c)
boolean	retainAll(Collection c)
protected abstract E	retrieveObjectForIndex(int index) Accessor to retrieve the object at an index.
Object	set(int index, Object element)
int	size()
List	subList(int fromIndex, int toIndex)
Object[]	toArray()
Object[]	toArray(Object[] a)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.List

equals, hashCode, replaceAll, sort, spliterator

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

size

protected int size

Cached size of the list. -1 when not known.

Constructor Detail

AbstractLazyLoadList

public AbstractLazyLoadList(String cacheType)

Constructor for a lazy load list.

Parameters:

cacheType - Type of caching of objects in the list

Method Detail

retrieveObjectForIndex

protected abstract E retrieveObjectForIndex(int index)

Accessor to retrieve the object at an index. Is only called if the object is not currently cached.

Parameters:

index - The list index

Returns:

The object

getSize

protected abstract int getSize()

Method to return the size of the list.

Returns:

The size

isOpen

protected boolean isOpen()

Accessor whether the list is open. Always open in this implementation but can be overridden if you want to allow closure.

Returns:

Whether it is open.

add

public void add(int index,
                Object element)

Specified by:

add in interface List<E>

add

public boolean add(Object e)

Specified by:

add in interface Collection<E>

Specified by:

add in interface List<E>

addAll

public boolean addAll(Collection c)

Specified by:

addAll in interface Collection<E>

Specified by:

addAll in interface List<E>

addAll

public boolean addAll(int index,
                      Collection c)

Specified by:

addAll in interface List<E>

clear

public void clear()

Specified by:

clear in interface Collection<E>

Specified by:

clear in interface List<E>

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<E>

Specified by:

contains in interface List<E>

containsAll

public boolean containsAll(Collection c)

Specified by:

containsAll in interface Collection<E>

Specified by:

containsAll in interface List<E>

get

public E get(int index)

Specified by:

get in interface List<E>

indexOf

public int indexOf(Object o)

Specified by:

indexOf in interface List<E>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

Specified by:

isEmpty 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>

lastIndexOf

public int lastIndexOf(Object o)

Specified by:

lastIndexOf in interface List<E>

listIterator

public ListIterator listIterator()

Specified by:

listIterator in interface List<E>

listIterator

public ListIterator listIterator(int index)

Specified by:

listIterator in interface List<E>

remove

public E remove(int index)

Specified by:

remove in interface List<E>

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<E>

Specified by:

remove in interface List<E>

removeAll

public boolean removeAll(Collection c)

Specified by:

removeAll in interface Collection<E>

Specified by:

removeAll in interface List<E>

retainAll

public boolean retainAll(Collection c)

Specified by:

retainAll in interface Collection<E>

Specified by:

retainAll in interface List<E>

set

public Object set(int index,
                  Object element)

Specified by:

set in interface List<E>

size

public int size()

Specified by:

size in interface Collection<E>

Specified by:

size in interface List<E>

subList

public List subList(int fromIndex,
                    int toIndex)

Specified by:

subList in interface List<E>

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface List<E>

toArray

public Object[] toArray(Object[] a)

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface List<E>