org.apache.commons.collections4.map

## Class LazySortedMap<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.LazyMap<K,V>
      - - org.apache.commons.collections4.map.LazySortedMap<K,V>

- All Implemented Interfaces:
    Serializable, Map<K,V>, SortedMap<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>

      public class LazySortedMap<K,V>
      extends LazyMap<K,V>
      implements SortedMap<K,V>

  Decorates another `SortedMap` to create objects in the map on demand.

  When the `LazyMap.get(Object)` method is called with a key that does not exist in the map, the factory is used to create the object. The created object will be added to the map using the requested key.

  For instance:

       Factory<Date> factory = new Factory<Date>() {
           public Date create() {
               return new Date();
           }
       }
       SortedMap<String, Date> lazy =
           LazySortedMap.lazySortedMap(new HashMap<String, Date>(), factory);
       Date date = lazy.get("NOW");

  After the above code is executed, `date` will refer to a new `Date` instance. Furthermore, that `Date` instance is mapped to the "NOW" key in the map.

  Note that LazySortedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using `Collections.synchronizedSortedMap(java.util.SortedMap<K, V>)`. This class may throw exceptions when accessed by concurrent threads without synchronization.

  This class is Serializable from Commons Collections 3.1.

  Since:
    3.0
  Version:
    $Id: LazySortedMap.java 1686855 2015-06-22 13:00:27Z tn $
  See Also:
    Serialized Form

- - ### Nested Class Summary

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

      `Map.Entry<K,V>`

  - ### Field Summary

    - ### Fields inherited from class org.apache.commons.collections4.map.LazyMap

      `factory`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `LazySortedMap(SortedMap<K,V> map, Factory<? extends V> factory)` Constructor that wraps (not copies).
    `protected` | `LazySortedMap(SortedMap<K,V> map, Transformer<? super K,? extends V> factory)` Constructor that wraps (not copies).

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `Comparator<? super K>` | `comparator()`
    `K` | `firstKey()`
    `protected SortedMap<K,V>` | `getSortedMap()` Gets the map being decorated.
    `SortedMap<K,V>` | `headMap(K toKey)`
    `K` | `lastKey()`
    `static <K,V> LazySortedMap<K,V>` | `lazySortedMap(SortedMap<K,V> map, Factory<? extends V> factory)` Factory method to create a lazily instantiated sorted map.
    `static <K,V> LazySortedMap<K,V>` | `lazySortedMap(SortedMap<K,V> map, Transformer<? super K,? extends V> factory)` Factory method to create a lazily instantiated sorted map.
    `SortedMap<K,V>` | `subMap(K fromKey, K toKey)`
    `SortedMap<K,V>` | `tailMap(K fromKey)`

    - ### Methods inherited from class org.apache.commons.collections4.map.LazyMap

      `get, lazyMap, lazyMap`

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

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

    - ### Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap

      `mapIterator`

    - ### Methods inherited from class java.lang.Object

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

    - ### Methods inherited from interface java.util.SortedMap

      `entrySet, keySet, values`

    - ### Methods inherited from interface java.util.Map

      `clear, containsKey, containsValue, equals, get, hashCode, isEmpty, put, putAll, remove, size`

- - ### Constructor Detail

    - #### LazySortedMap

          protected LazySortedMap(SortedMap<K,V> map,
                       Factory<? extends V> factory)

      Constructor that wraps (not copies).
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Throws:
        `NullPointerException` - if map or factory is null

    - #### LazySortedMap

          protected LazySortedMap(SortedMap<K,V> map,
                       Transformer<? super K,? extends V> factory)

      Constructor that wraps (not copies).
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Throws:
        `NullPointerException` - if map or factory is null

  - ### Method Detail

    - #### lazySortedMap

          public static <K,V> LazySortedMap<K,V> lazySortedMap(SortedMap<K,V> map,
                                               Factory<? extends V> factory)

      Factory method to create a lazily instantiated sorted map.
      Type Parameters:
        `K` - the key type
        `V` - the value type
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Returns:
        a new lazy sorted map
      Throws:
        `NullPointerException` - if map or factory is null
      Since:
        4.0

    - #### lazySortedMap

          public static <K,V> LazySortedMap<K,V> lazySortedMap(SortedMap<K,V> map,
                                               Transformer<? super K,? extends V> factory)

      Factory method to create a lazily instantiated sorted map.
      Type Parameters:
        `K` - the key type
        `V` - the value type
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Returns:
        a new lazy sorted map
      Throws:
        `NullPointerException` - if map or factory is null
      Since:
        4.0

    - #### getSortedMap

          protected SortedMap<K,V> getSortedMap()

      Gets the map being decorated.
      Returns:
        the decorated map

    - #### firstKey

          public K firstKey()

      Specified by:
        `firstKey` in interface `SortedMap<K,V>`

    - #### lastKey

          public K lastKey()

      Specified by:
        `lastKey` in interface `SortedMap<K,V>`

    - #### comparator

          public Comparator<? super K> comparator()

      Specified by:
        `comparator` in interface `SortedMap<K,V>`

    - #### subMap

          public SortedMap<K,V> subMap(K fromKey,
                              K toKey)

      Specified by:
        `subMap` in interface `SortedMap<K,V>`

    - #### headMap

          public SortedMap<K,V> headMap(K toKey)

      Specified by:
        `headMap` in interface `SortedMap<K,V>`

    - #### tailMap

          public SortedMap<K,V> tailMap(K fromKey)

      Specified by:
        `tailMap` in interface `SortedMap<K,V>`

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