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java.lang.Object org.apache.commons.collections.map.AbstractMapDecorator org.apache.commons.collections.map.LazyMap org.apache.commons.collections.map.LazySortedMap
public class LazySortedMap
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.
Nested Class Summary |
---|
Nested classes/interfaces inherited from interface java.util.Map |
---|
java.util.Map.Entry |
Field Summary |
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Fields inherited from class org.apache.commons.collections.map.LazyMap |
---|
factory |
Fields inherited from class org.apache.commons.collections.map.AbstractMapDecorator |
---|
map |
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.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.Map |
---|
clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values |
Constructor Detail |
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protected LazySortedMap(java.util.SortedMap map, Factory factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
java.lang.IllegalArgumentException
- if map or factory is nullprotected LazySortedMap(java.util.SortedMap map, Transformer factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
java.lang.IllegalArgumentException
- if map or factory is nullMethod Detail |
---|
public static java.util.SortedMap decorate(java.util.SortedMap map, Factory factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
java.lang.IllegalArgumentException
- if map or factory is nullpublic static java.util.SortedMap decorate(java.util.SortedMap map, Transformer factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
java.lang.IllegalArgumentException
- if map or factory is nullprotected java.util.SortedMap getSortedMap()
public java.lang.Object firstKey()
firstKey
in interface java.util.SortedMap
public java.lang.Object lastKey()
lastKey
in interface java.util.SortedMap
public java.util.Comparator comparator()
comparator
in interface java.util.SortedMap
public java.util.SortedMap subMap(java.lang.Object fromKey, java.lang.Object toKey)
subMap
in interface java.util.SortedMap
public java.util.SortedMap headMap(java.lang.Object toKey)
headMap
in interface java.util.SortedMap
public java.util.SortedMap tailMap(java.lang.Object fromKey)
tailMap
in interface java.util.SortedMap
|
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