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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:
Map, Map, SortedMap


public class LazySortedMap
extends LazyMap
implements SortedMap

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

When the 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.
Since:
Commons Collections 3.0
Authors:
Stephen Colebourne
Paul Jack

Constructor Summary

LazySortedMap(SortedMap map, Factory factory)

Constructor that wraps (not copies).

LazySortedMap(SortedMap map, Transformer factory)

Constructor that wraps (not copies).

Method Summary

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()

SortedMap

getSortedMap()

Gets the map being decorated.

SortedMap

headMap(Object toKey)

Object

lastKey()

SortedMap

subMap(Object fromKey, Object toKey)

SortedMap

tailMap(Object fromKey)

Constructor Details

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:
- 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:
- if map or factory is null

Method Details

comparator

public Comparator comparator()


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:
- 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:
- if map or factory is null

firstKey

public Object firstKey()


getSortedMap

protected SortedMap getSortedMap()

Gets the map being decorated.

Returns:
the decorated map

headMap

public SortedMap headMap(Object toKey)

Parameters:
toKey

lastKey

public Object lastKey()


subMap

public SortedMap subMap(Object fromKey, Object toKey)

Parameters:
fromKey
toKey

tailMap

public SortedMap tailMap(Object fromKey)

Parameters:
fromKey