cz.cuni.amis.utils.maps

Class WeakHashMapMap<PRIMARY_KEY,SECONDARY_KEY,ITEM>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

cz.cuni.amis.utils.maps.WeakHashMapMap<PRIMARY_KEY,SECONDARY_KEY,ITEM>

Type Parameters:

PRIMARY_KEY -

SECONDARY_KEY -

ITEM -

All Implemented Interfaces:

Map<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

public class WeakHashMapMap<PRIMARY_KEY,SECONDARY_KEY,ITEM>
extends WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

Two-level hashMap where the first-level keys are weakly referenced! This means that if the key is not strongly referenced elsewhere, the maps can be garbage collected.

Author:

srlok

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

Constructors

Constructor and Description
WeakHashMapMap()

Method Summary

Modifier and Type	Method and Description
Map<SECONDARY_KEY,ITEM>	get(Object primaryKey)
ITEM	get(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey) Returns the requested item under primary and secondary key.
ITEM	put(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey, ITEM item) Inserts item under primary and secondary_key.
Map<SECONDARY_KEY,ITEM>	remove(Object primaryKey) removes all items under primaryKey
ITEM	remove2(PRIMARY_KEY primaryKey, SECONDARY_KEY secondaryKey) removes the item under primary and secondary key.

Methods inherited from class java.util.WeakHashMap

clear, containsKey, containsValue, entrySet, forEach, isEmpty, keySet, put, putAll, replaceAll, size, values

Methods inherited from class java.util.AbstractMap

clone, equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace

Constructor Detail

WeakHashMapMap

public WeakHashMapMap()

Method Detail

get

public Map<SECONDARY_KEY,ITEM> get(Object primaryKey)

Specified by:

get in interface Map<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

Overrides:

get in class WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

get

public ITEM get(PRIMARY_KEY primaryKey,
                SECONDARY_KEY secondaryKey)

Returns the requested item under primary and secondary key.

Parameters:

primaryKey - weakly-referenced

secondaryKey -

Returns:

if no such item exists returns NULL

put

public ITEM put(PRIMARY_KEY primaryKey,
                SECONDARY_KEY secondaryKey,
                ITEM item)

Inserts item under primary and secondary_key.

Parameters:

primaryKey - weakly-referenced

secondaryKey -

item -

Returns:

inserted item

remove2

public ITEM remove2(PRIMARY_KEY primaryKey,
                    SECONDARY_KEY secondaryKey)

removes the item under primary and secondary key.

Parameters:

primaryKey -

secondaryKey -

Returns:

removed item

remove

public Map<SECONDARY_KEY,ITEM> remove(Object primaryKey)

removes all items under primaryKey

Specified by:

remove in interface Map<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

Overrides:

remove in class WeakHashMap<PRIMARY_KEY,Map<SECONDARY_KEY,ITEM>>

Parameters:

primaryKey -

Returns:

map of all removed items