org.apache.commons.collections.map

Class AbstractOrderedMapDecorator

java.lang.Object

org.apache.commons.collections.map.AbstractMapDecorator

org.apache.commons.collections.map.AbstractOrderedMapDecorator

All Implemented Interfaces:

java.util.Map, IterableMap, OrderedMap

Direct Known Subclasses:

UnmodifiableOrderedMap

public abstract class AbstractOrderedMapDecorator
extends AbstractMapDecorator
implements OrderedMap

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:

Commons Collections 3.0

Nested Class Summary

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

java.util.Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
AbstractOrderedMapDecorator(OrderedMap map) Constructor that wraps (not copies).

Method Summary

Modifier and Type	Method and Description
java.lang.Object	firstKey() Gets the first key currently in this map.
java.lang.Object	lastKey() Gets the last key currently in this map.
MapIterator	mapIterator() Obtains a MapIterator over the map.
java.lang.Object	nextKey(java.lang.Object key) Gets the next key after the one specified.
OrderedMapIterator	orderedMapIterator() Obtains an OrderedMapIterator over the map.
java.lang.Object	previousKey(java.lang.Object key) Gets the previous key before the one specified.

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

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

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

Constructor Detail

AbstractOrderedMapDecorator

public AbstractOrderedMapDecorator(OrderedMap map)

Constructor that wraps (not copies).

Parameters:

map - the map to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if the collection is null

Method Detail

firstKey

public java.lang.Object firstKey()

Description copied from interface: OrderedMap

Gets the first key currently in this map.

Specified by:

firstKey in interface OrderedMap

Returns:

the first key currently in this map

lastKey

public java.lang.Object lastKey()

Description copied from interface: OrderedMap

Gets the last key currently in this map.

Specified by:

lastKey in interface OrderedMap

Returns:

the last key currently in this map

nextKey

public java.lang.Object nextKey(java.lang.Object key)

Description copied from interface: OrderedMap

Gets the next key after the one specified.

Specified by:

nextKey in interface OrderedMap

Parameters:

key - the key to search for next from

Returns:

the next key, null if no match or at end

previousKey

public java.lang.Object previousKey(java.lang.Object key)

Description copied from interface: OrderedMap

Gets the previous key before the one specified.

Specified by:

previousKey in interface OrderedMap

Parameters:

key - the key to search for previous from

Returns:

the previous key, null if no match or at start

mapIterator

public MapIterator mapIterator()

Description copied from interface: IterableMap

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 cast to Map Entry objects.

 IterableMap map = new HashedMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
 }
 

Specified by:

mapIterator in interface IterableMap

Returns:

a map iterator

orderedMapIterator

public OrderedMapIterator orderedMapIterator()

Description copied from interface: OrderedMap

Obtains an OrderedMapIterator over the map.

A ordered map iterator is an efficient way of iterating over maps in both directions.

 BidiMap map = new TreeBidiMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
   Object previousKey = it.previous();
 }
 

Specified by:

orderedMapIterator in interface OrderedMap

Returns:

a map iterator