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.io.Serializable, 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.
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 13:33:15 +0100 (Thu, 10 Apr 2008) $
- Author:
- Stephen Colebourne, Paul Jack
- See Also:
- Serialized Form
Nested classes/interfaces inherited from interface java.util.Map |
java.util.Map.Entry<K,V> |
Fields inherited from class org.apache.commons.collections.map.LazyMap |
factory |
Constructor Summary |
protected |
LazySortedMap(java.util.SortedMap map,
Factory factory)
Constructor that wraps (not copies). |
protected |
LazySortedMap(java.util.SortedMap map,
Transformer factory)
Constructor that wraps (not copies). |
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()
|
protected java.util.SortedMap |
getSortedMap()
Gets the map being decorated. |
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.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 |
LazySortedMap
protected LazySortedMap(java.util.SortedMap map,
Factory factory)
- Constructor that wraps (not copies).
- Parameters:
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
- Throws:
java.lang.IllegalArgumentException
- if map or factory is null
LazySortedMap
protected LazySortedMap(java.util.SortedMap map,
Transformer factory)
- Constructor that wraps (not copies).
- Parameters:
map
- the map to decorate, must not be nullfactory
- 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,
Factory factory)
- Factory method to create a lazily instantiated sorted map.
- Parameters:
map
- the map to decorate, must not be nullfactory
- 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 nullfactory
- the factory to use, must not be null
- Throws:
java.lang.IllegalArgumentException
- if map or factory is null
getSortedMap
protected java.util.SortedMap getSortedMap()
- Gets the map being decorated.
- Returns:
- the decorated map
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
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