com.whitestein.lsps.common.collections

Class MapLikeListAccessor<K extends java.lang.Comparable<K>,V>

java.lang.Object

com.whitestein.lsps.common.collections.MapLikeListAccessor<K,V>

Type Parameters:

K - type of the key/attribute

V - type of the list element

public class MapLikeListAccessor<K extends java.lang.Comparable<K>,V>
extends java.lang.Object

Map like adapter/helper class for accessing (sorted) list of values by their attribute. The accessor is meant to provide efficient key/attribute based lookup where keeping separate map is not efficient from memory consumption reasons. The underlying list has to be sorted by the requested attribute and must not be modified outside this accessor, or it has to be ensured that it is re-sorted after each such external list modification

Constructor Summary

Constructors

Constructor and Description
MapLikeListAccessor(java.util.function.Function<V,K> keyGetter) Constructor

Method Summary

Modifier and Type	Method and Description
void	add(V value, java.util.List<V> list) Answer a value with specified key attribute
boolean	containsKey(K key, java.util.List<V> list) Answer keys
V	get(K key, java.util.List<V> list) Answer a value with specified key attribute
java.util.Set<K>	keySet(java.util.List<V> list) Answer keys
static <K extends java.lang.Comparable<K>,V> MapLikeListAccessor<K,V>	on(java.util.function.Function<V,K> keyGetter) Factory method
void	sort(java.util.List<V> list) Sort the underlying list by the key values

Methods inherited from class java.lang.Object

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

Constructor Detail

MapLikeListAccessor

public MapLikeListAccessor(java.util.function.Function<V,K> keyGetter)

Constructor

Parameters:

keyGetter -

Method Detail

on

public static <K extends java.lang.Comparable<K>,V> MapLikeListAccessor<K,V> on(java.util.function.Function<V,K> keyGetter)

Factory method

Type Parameters:

K - type of the key/attribute

V - type of the list element

Parameters:

keyGetter -

Returns:

instance of list

sort

public void sort(java.util.List<V> list)

Sort the underlying list by the key values

Parameters:

list -

containsKey

public boolean containsKey(K key,
                           java.util.List<V> list)

Answer keys

Parameters:

key -

list -

Returns:

keys

get

public V get(K key,
             java.util.List<V> list)

Answer a value with specified key attribute

Parameters:

key -

list -

Returns:

value with key or null if no such present

add

public void add(V value,
                java.util.List<V> list)

Answer a value with specified key attribute

Parameters:

value -

list -

keySet

public java.util.Set<K> keySet(java.util.List<V> list)

Answer keys

Parameters:

list -

Returns:

keys