Package org.apache.commons.collections4.map

Class AbstractOrderedMapDecorator<K,V>

java.lang.Object

org.apache.commons.collections4.map.AbstractIterableMap<K,V>

org.apache.commons.collections4.map.AbstractMapDecorator<K,V>

org.apache.commons.collections4.map.AbstractOrderedMapDecorator<K,V>

Type Parameters:

K - the type of the keys in this map

V - the type of the values in this map

All Implemented Interfaces:

Map<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, OrderedMap<K,V>, Put<K,V>

Direct Known Subclasses:

UnmodifiableOrderedMap

public abstract class AbstractOrderedMapDecorator<K,V>
extends AbstractMapDecorator<K,V>
implements OrderedMap<K,V>

Provides a base decorator that enables additional functionality to be added to an OrderedMap via decoration.

Methods are forwarded directly to the decorated map.

This implementation does not perform any special processing with the map views. Instead it simply returns the set/collection from the wrapped map. This may be undesirable, for example if you are trying to write a validating implementation it would provide a loophole around the validation. But, you might want that loophole, so this class is kept simple.

Since:

3.0

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractOrderedMapDecorator()	Constructor only used in deserialization, do not use otherwise.
	AbstractOrderedMapDecorator(OrderedMap<K,V> map)	Constructor that wraps (not copies).

Method Summary

Modifier and Type	Method	Description
protected OrderedMap<K,V>	decorated()	Gets the map being decorated.
K	firstKey()	Gets the first key currently in this map.
K	lastKey()	Gets the last key currently in this map.
OrderedMapIterator<K,V>	mapIterator()	Obtains a MapIterator over the map.
K	nextKey(K key)	Gets the next key after the one specified.
K	previousKey(K key)	Gets the previous key before the one specified.

Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.collections4.Get

containsKey, containsValue, entrySet, get, isEmpty, keySet, remove, size, values

Methods inherited from interface java.util.Map

clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

Methods inherited from interface org.apache.commons.collections4.Put

clear, put, putAll

Constructor Details

AbstractOrderedMapDecorator

protected AbstractOrderedMapDecorator()

Constructor only used in deserialization, do not use otherwise.

Since:

3.1

AbstractOrderedMapDecorator

public AbstractOrderedMapDecorator(OrderedMap<K,V> map)

Constructor that wraps (not copies).

Parameters:

map - the map to decorate, must not be null

Throws:

NullPointerException - if the map is null

Method Details

decorated

protected OrderedMap<K,V> decorated()

Gets the map being decorated.

Overrides:

decorated in class AbstractMapDecorator<K,V>

Returns:

the decorated map

firstKey

public K firstKey()

Description copied from interface: OrderedMap

Gets the first key currently in this map.

Specified by:

firstKey in interface OrderedMap<K,V>

Returns:

the first key currently in this map

lastKey

public K lastKey()

Description copied from interface: OrderedMap

Gets the last key currently in this map.

Specified by:

lastKey in interface OrderedMap<K,V>

Returns:

the last key currently in this map

mapIterator

public OrderedMapIterator<K,V> mapIterator()

Description copied from class: AbstractIterableMap

Obtains a MapIterator over the map.

A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or use Map Entry objects.

 IterableMap<String,Integer> map = new HashedMap<String,Integer>();
 MapIterator<String,Integer> it = map.mapIterator();
 while (it.hasNext()) {
   String key = it.next();
   Integer value = it.getValue();
   it.setValue(value + 1);
 }
 

Specified by:

mapIterator in interface IterableGet<K,V>

Specified by:

mapIterator in interface OrderedMap<K,V>

Overrides:

mapIterator in class AbstractIterableMap<K,V>

Returns:

a map iterator

nextKey

public K nextKey(K key)

Description copied from interface: OrderedMap

Gets the next key after the one specified.

Specified by:

nextKey in interface OrderedMap<K,V>

Parameters:

key - the key to search for next from

Returns:

the next key, null if no match or at end

previousKey

public K previousKey(K key)

Description copied from interface: OrderedMap

Gets the previous key before the one specified.

Specified by:

previousKey in interface OrderedMap<K,V>

Parameters:

key - the key to search for previous from

Returns:

the previous key, null if no match or at start