org.apache.commons.collections.map

## Class LazySortedMap

- java.lang.Object
- - org.apache.commons.collections.map.AbstractMapDecorator
  - - org.apache.commons.collections.map.LazyMap
    - - org.apache.commons.collections.map.LazySortedMap

- All Implemented Interfaces:
    Serializable, Map, SortedMap

      public class LazySortedMap
      extends LazyMap
      implements SortedMap

  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 factory = new Factory() {
           public Object create() {
               return new Date();
           }
       }
       SortedMap lazy = Lazy.sortedMap(new HashMap(), factory);
       Object obj = lazy.get("NOW");

  After the above code is executed, `obj` will contain 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)`. This class may throw exceptions when accessed by concurrent threads without synchronization.

  This class is Serializable from Commons Collections 3.1.

  Since:
    Commons Collections 3.0
  Version:
    $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
  Author:
    Stephen Colebourne, Paul Jack
  See Also:
    Serialized Form

- - ### Nested Class Summary

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

      `Map.Entry`

  - ### Field Summary

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

      `factory`

    - ### Fields inherited from class org.apache.commons.collections.map.AbstractMapDecorator

      `map`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `LazySortedMap(SortedMap map, Factory factory)` Constructor that wraps (not copies).
    `protected` | `LazySortedMap(SortedMap map, Transformer factory)` Constructor that wraps (not copies).

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `Comparator` | `comparator()`
    `static SortedMap` | `decorate(SortedMap map, Factory factory)` Factory method to create a lazily instantiated sorted map.
    `static SortedMap` | `decorate(SortedMap map, Transformer factory)` Factory method to create a lazily instantiated sorted map.
    `Object` | `firstKey()`
    `protected SortedMap` | `getSortedMap()` Gets the map being decorated.
    `SortedMap` | `headMap(Object toKey)`
    `Object` | `lastKey()`
    `SortedMap` | `subMap(Object fromKey, Object toKey)`
    `SortedMap` | `tailMap(Object fromKey)`

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

      `decorate, decorate, get`

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

      `clear, containsKey, containsValue, entrySet, equals, getMap, 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.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 map,
                       Factory 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:
        `IllegalArgumentException` - if map or factory is null

    - #### LazySortedMap

          protected LazySortedMap(SortedMap map,
                       Transformer 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:
        `IllegalArgumentException` - if map or factory is null

  - ### Method Detail

    - #### decorate

          public static SortedMap decorate(SortedMap map,
                           Factory factory)

      Factory method to create a lazily instantiated sorted map.
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Throws:
        `IllegalArgumentException` - if map or factory is null

    - #### decorate

          public static SortedMap decorate(SortedMap map,
                           Transformer factory)

      Factory method to create a lazily instantiated sorted map.
      Parameters:
        `map` - the map to decorate, must not be null
        `factory` - the factory to use, must not be null
      Throws:
        `IllegalArgumentException` - if map or factory is null

    - #### getSortedMap

          protected SortedMap getSortedMap()

      Gets the map being decorated.
      Returns:
        the decorated map

    - #### firstKey

          public Object firstKey()

      Specified by:
        `firstKey` in interface `SortedMap`

    - #### lastKey

          public Object lastKey()

      Specified by:
        `lastKey` in interface `SortedMap`

    - #### comparator

          public Comparator comparator()

      Specified by:
        `comparator` in interface `SortedMap`

    - #### subMap

          public SortedMap subMap(Object fromKey,
                         Object toKey)

      Specified by:
        `subMap` in interface `SortedMap`

    - #### headMap

          public SortedMap headMap(Object toKey)

      Specified by:
        `headMap` in interface `SortedMap`

    - #### tailMap

          public SortedMap tailMap(Object fromKey)

      Specified by:
        `tailMap` in interface `SortedMap`

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