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:

java.util.Map, java.util.SortedMap

public class LazySortedMap

extends LazyMap

implements java.util.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.

Since:

Commons Collections 3.0

Version:

$Revision: 1.3 $ $Date: 2004/01/14 21:43:11 $

Author:

Stephen Colebourne, Paul Jack

Method Summary

java.util.Comparator	comparator()
static java.util.SortedMap	decorate(java.util.SortedMap map, Factory factory) Factory method to create a lazily instantiated sorted map.
static java.util.SortedMap	decorate(java.util.SortedMap map, Transformer factory) Factory method to create a lazily instantiated sorted map.
java.lang.Object	firstKey()
java.util.SortedMap	headMap(java.lang.Object toKey)
java.lang.Object	lastKey()
java.util.SortedMap	subMap(java.lang.Object fromKey, java.lang.Object toKey)
java.util.SortedMap	tailMap(java.lang.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, 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, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Method Detail

decorate

public static java.util.SortedMap decorate(java.util.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:

java.lang.IllegalArgumentException - if map or factory is null

decorate

public static java.util.SortedMap decorate(java.util.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:

java.lang.IllegalArgumentException - if map or factory is null

firstKey

public java.lang.Object firstKey()

Specified by:

firstKey in interface java.util.SortedMap

lastKey

public java.lang.Object lastKey()

Specified by:

lastKey in interface java.util.SortedMap

comparator

public java.util.Comparator comparator()

Specified by:

comparator in interface java.util.SortedMap

subMap

public java.util.SortedMap subMap(java.lang.Object fromKey,
                                  java.lang.Object toKey)

Specified by:

subMap in interface java.util.SortedMap

headMap

public java.util.SortedMap headMap(java.lang.Object toKey)

Specified by:

headMap in interface java.util.SortedMap

tailMap

public java.util.SortedMap tailMap(java.lang.Object fromKey)

Specified by:

tailMap in interface java.util.SortedMap