Package org.apache.sis.feature

Class PropertySingleton<V>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<V>

org.apache.sis.feature.PropertySingleton<V>

All Implemented Interfaces:

Iterable<V>, Collection<V>, List<V>

final class PropertySingleton<V>
extends AbstractList<V>

A list containing 0 or 1 value. This implementation is used in the very common case where a AbstractAttribute accepts at most one value. Its main purpose is to reduce the amount of objects in memory compared to ArrayList.

There is no need to keep long-lived references to instances of this class. Instances can be recreated when needed.

Since:

0.5

Version:

0.5

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private final class	PropertySingleton.Iter	Implementation of the iterator returned by iterator().

Field Summary

Fields

Modifier and Type	Field	Description
private final Field<V>	property	The property where to read and write the value.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
PropertySingleton(Field<V> property)	Creates a new list for the value of the given property.

Method Summary

Modifier and Type	Method	Description
void	add(int index, V element)	Sets the property value, if no instance existed prior this method call.
boolean	add(V element)	Sets the property value, if no instance existed prior this method call.
void	clear()	Removes the property value.
(package private) final void	clear(int c)	Removes the singleton value, if presents.
boolean	equals(Object other)	Same contract than AbstractList, just slightly more efficient for this particular class.
V	get(int index)	Returns the property value, if present.
int	hashCode()	Same contract than AbstractList, just slightly more efficient for this particular class.
int	indexOf(Object element)	Returns the index of the given element (which can only be 0), or -1 if not present.
Iterator<V>	iterator()	Returns an iterator over the unique element in this list.
int	lastIndexOf(Object element)	Returns the index of the given element (which can only be 0), or -1 if not present.
V	remove(int index)	Removes the property value.
V	set(int index, V element)	Sets the property value, if an instance already exists.
int	size()	Returns 1 or 0, depending on whether or not a value exists.
Object[]	toArray()	Returns an array wrapping the singleton value, or an empty array if none.

Methods inherited from class java.util.AbstractList

addAll, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

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

Field Details

property

private final Field<V> property

The property where to read and write the value.

Constructor Details

PropertySingleton

PropertySingleton(Field<V> property)

Creates a new list for the value of the given property.

Method Details

size

public int size()

Returns 1 or 0, depending on whether or not a value exists.

Specified by:

size in interface Collection<V>

Specified by:

size in interface List<V>

Specified by:

size in class AbstractCollection<V>

indexOf

public int indexOf(Object element)

Returns the index of the given element (which can only be 0), or -1 if not present.

Specified by:

indexOf in interface List<V>

Overrides:

indexOf in class AbstractList<V>

lastIndexOf

public int lastIndexOf(Object element)

Returns the index of the given element (which can only be 0), or -1 if not present.

Specified by:

lastIndexOf in interface List<V>

Overrides:

lastIndexOf in class AbstractList<V>

get

public V get(int index)

Returns the property value, if present.

Specified by:

get in interface List<V>

Specified by:

get in class AbstractList<V>

set

public V set(int index,
 V element)

Sets the property value, if an instance already exists.

Specified by:

set in interface List<V>

Overrides:

set in class AbstractList<V>

add

public void add(int index,
 V element)

Sets the property value, if no instance existed prior this method call.

Specified by:

add in interface List<V>

Overrides:

add in class AbstractList<V>

add

public boolean add(V element)

Sets the property value, if no instance existed prior this method call.

Specified by:

add in interface Collection<V>

Specified by:

add in interface List<V>

Overrides:

add in class AbstractList<V>

remove

public V remove(int index)

Removes the property value. This method does not checks if the removal is allowed by the multiplicity. Such check can be performed by AbstractFeature.quality().

Specified by:

remove in interface List<V>

Overrides:

remove in class AbstractList<V>

clear

final void clear(int c)

Removes the singleton value, if presents. This method is for PropertySingleton.Iter.remove() implementation only.

Parameters:

c - the expected AbstractList.modCount value, for check against concurrent modification.

clear

public void clear()

Removes the property value. This method does not checks if the removal is allowed by the multiplicity. Such check can be performed by AbstractFeature.quality().

Specified by:

clear in interface Collection<V>

Specified by:

clear in interface List<V>

Overrides:

clear in class AbstractList<V>

toArray

public Object[] toArray()

Returns an array wrapping the singleton value, or an empty array if none.

Specified by:

toArray in interface Collection<V>

Specified by:

toArray in interface List<V>

Overrides:

toArray in class AbstractCollection<V>

hashCode

public int hashCode()

Same contract than AbstractList, just slightly more efficient for this particular class.

Specified by:

hashCode in interface Collection<V>

Specified by:

hashCode in interface List<V>

Overrides:

hashCode in class AbstractList<V>

equals

public boolean equals(Object other)

Same contract than AbstractList, just slightly more efficient for this particular class.

Specified by:

equals in interface Collection<V>

Specified by:

equals in interface List<V>

Overrides:

equals in class AbstractList<V>

iterator

public Iterator<V> iterator()

Returns an iterator over the unique element in this list.

Specified by:

iterator in interface Collection<V>

Specified by:

iterator in interface Iterable<V>

Specified by:

iterator in interface List<V>

Overrides:

iterator in class AbstractList<V>