org.springframework.util

Class AutoPopulatingList<E>

java.lang.Object

org.springframework.util.AutoPopulatingList<E>

Type Parameters:

E - the element type

All Implemented Interfaces:

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

public class AutoPopulatingList<E>
extends Object
implements List<E>, Serializable

Simple List wrapper class that allows for elements to be automatically populated as they are requested. This is particularly useful for data binding to Lists, allowing for elements to be created and added to the List in a "just in time" fashion.

Note: This class is not thread-safe. To create a thread-safe version, use the Collections.synchronizedList(java.util.List<T>) utility methods.

Inspired by LazyList from Commons Collections.

Since:

2.0

Author:

Rob Harrop, Juergen Hoeller

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AutoPopulatingList.ElementFactory<E> Factory interface for creating elements for an index-based access data structure such as a List.
static class	AutoPopulatingList.ElementInstantiationException Exception to be thrown from ElementFactory.

Constructor Summary

Constructors

Constructor and Description
AutoPopulatingList(AutoPopulatingList.ElementFactory<E> elementFactory) Creates a new AutoPopulatingList that is backed by a standard ArrayList and creates new elements on demand using the supplied AutoPopulatingList.ElementFactory.
AutoPopulatingList(Class<? extends E> elementClass) Creates a new AutoPopulatingList that is backed by a standard ArrayList and adds new instances of the supplied element Class to the backing List on demand.
AutoPopulatingList(List<E> backingList, AutoPopulatingList.ElementFactory<E> elementFactory) Creates a new AutoPopulatingList that is backed by the supplied List and creates new elements on demand using the supplied AutoPopulatingList.ElementFactory.
AutoPopulatingList(List<E> backingList, Class<? extends E> elementClass) Creates a new AutoPopulatingList that is backed by the supplied List and adds new instances of the supplied element Class to the backing List on demand.

Method Summary

Modifier and Type	Method and Description
boolean	add(E o)
void	add(int index, E element)
boolean	addAll(Collection<? extends E> c)
boolean	addAll(int index, Collection<? extends E> c)
void	clear()
boolean	contains(Object o)
boolean	containsAll(Collection<?> c)
boolean	equals(Object other)
E	get(int index) Get the element at the supplied index, creating it if there is no element at that index.
int	hashCode()
int	indexOf(Object o)
boolean	isEmpty()
Iterator<E>	iterator()
int	lastIndexOf(Object o)
ListIterator<E>	listIterator()
ListIterator<E>	listIterator(int index)
E	remove(int index)
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
boolean	retainAll(Collection<?> c)
E	set(int index, E element)
int	size()
List<E>	subList(int fromIndex, int toIndex)
Object[]	toArray()
<T> T[]	toArray(T[] a)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, 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

AutoPopulatingList

public AutoPopulatingList(Class<? extends E> elementClass)

Creates a new AutoPopulatingList that is backed by a standard ArrayList and adds new instances of the supplied element Class to the backing List on demand.

AutoPopulatingList

public AutoPopulatingList(List<E> backingList,
                          Class<? extends E> elementClass)

Creates a new AutoPopulatingList that is backed by the supplied List and adds new instances of the supplied element Class to the backing List on demand.

AutoPopulatingList

public AutoPopulatingList(AutoPopulatingList.ElementFactory<E> elementFactory)

Creates a new AutoPopulatingList that is backed by a standard ArrayList and creates new elements on demand using the supplied AutoPopulatingList.ElementFactory.

AutoPopulatingList

public AutoPopulatingList(List<E> backingList,
                          AutoPopulatingList.ElementFactory<E> elementFactory)

Creates a new AutoPopulatingList that is backed by the supplied List and creates new elements on demand using the supplied AutoPopulatingList.ElementFactory.

Method Detail

add

public void add(int index,
                E element)

Specified by:

add in interface List<E>

add

public boolean add(E o)

Specified by:

add in interface Collection<E>

Specified by:

add in interface List<E>

addAll

public boolean addAll(Collection<? extends E> c)

Specified by:

addAll in interface Collection<E>

Specified by:

addAll in interface List<E>

addAll

public boolean addAll(int index,
                      Collection<? extends E> 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)

Get the element at the supplied index, creating it if there is no element at that 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<E> listIterator()

Specified by:

listIterator in interface List<E>

listIterator

public ListIterator<E> 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 E set(int index,
             E 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<E> 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 <T> T[] toArray(T[] a)

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface List<E>

equals

public boolean equals(@Nullable
                      Object other)

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