cz.cuni.amis.utils.maps

Class HashMapList<KEY,ITEM>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<KEY,List<ITEM>>

cz.cuni.amis.utils.maps.HashMapList<KEY,ITEM>

Type Parameters:

KEY -

ITEM -

All Implemented Interfaces:

Serializable, Cloneable, Map<KEY,List<ITEM>>

public class HashMapList<KEY,ITEM>
extends HashMap<KEY,List<ITEM>>

Map containing lists of items. Whenever a list under some key is requested and does not exists, the HashMapList automatically creates new one.

The implementation is unsynchronized, created lists are synchronized (just iteration over list must be synchronized by the user as described in Java(tm) documentation).

Author:

Jimmy

See Also:

Serialized Form

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
HashMapList()

Method Summary

Methods

Modifier and Type	Method and Description
void	add(KEY key, ITEM item) Add a new item at the end of the list under a specific key.
List<ITEM>	get(Object key) Returns a list under a specific key in the map.
ITEM	peek(KEY key) Returns first item from the list under a specific key.
ITEM	pull(KEY key) Removes first item from the list under a specific key.
ITEM	remove(KEY key, int index) Remove an item at 'index' from the list under a specific key.
List<ITEM>	remove(Object key) Remove returns the removed item, if item was non-existent, it returns empty list.

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, isEmpty, keySet, put, putAll, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

HashMapList

public HashMapList()

Method Detail

get

public List<ITEM> get(Object key)

Returns a list under a specific key in the map. If list does not exist, it automatically creates new (synchronized) one, inserts it into map and returns it.

Specified by:

get in interface Map<KEY,List<ITEM>>

Overrides:

get in class HashMap<KEY,List<ITEM>>

add

public void add(KEY key,
       ITEM item)

Add a new item at the end of the list under a specific key. If list does not exists, it automatically creates new (synchronized) one.

Parameters:

key -

item -

remove

public List<ITEM> remove(Object key)

Remove returns the removed item, if item was non-existent, it returns empty list.

Specified by:

remove in interface Map<KEY,List<ITEM>>

Overrides:

remove in class HashMap<KEY,List<ITEM>>

Parameters:

key -

Returns:

remove

public ITEM remove(KEY key,
          int index)

Remove an item at 'index' from the list under a specific key. The list bounds are not checked.

Parameters:

key -

index -

Returns:

peek

public ITEM peek(KEY key)

Returns first item from the list under a specific key. If the list is empty, returns null.

Parameters:

key -

Returns:

pull

public ITEM pull(KEY key)

Removes first item from the list under a specific key.

Parameters:

key -

Returns: