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

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and 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 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`

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

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

- - ### Constructor Detail

    - #### 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 Detail

    - #### 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

    - #### 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

    - #### 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

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