Class LazySortedMap<K,V>
- java.lang.Object
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- org.apache.commons.collections4.map.AbstractIterableMap<K,V>
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- org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
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- org.apache.commons.collections4.map.LazyMap<K,V>
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- org.apache.commons.collections4.map.LazySortedMap<K,V>
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- Type Parameters:
K
- the type of the keys in this mapV
- the type of the values in this map
- All Implemented Interfaces:
java.io.Serializable
,java.util.Map<K,V>
,java.util.SortedMap<K,V>
,Get<K,V>
,IterableGet<K,V>
,IterableMap<K,V>
,Put<K,V>
public class LazySortedMap<K,V> extends LazyMap<K,V> implements java.util.SortedMap<K,V>
Decorates anotherSortedMap
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<Date> factory = new Factory<Date>() { public Date create() { return new Date(); } } SortedMap<String, Date> lazy = LazySortedMap.lazySortedMap(new HashMap<String, Date>(), factory); Date date = lazy.get("NOW");
After the above code is executed,
date
will refer to a newDate
instance. Furthermore, thatDate
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<K, V>)
. This class may throw exceptions when accessed by concurrent threads without synchronization.This class is Serializable from Commons Collections 3.1.
- Since:
- 3.0
- See Also:
- Serialized Form
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description java.util.Comparator<? super K>
comparator()
K
firstKey()
java.util.SortedMap<K,V>
headMap(K toKey)
K
lastKey()
static <K,V>
LazySortedMap<K,V>lazySortedMap(java.util.SortedMap<K,V> map, Factory<? extends V> factory)
Factory method to create a lazily instantiated sorted map.static <K,V>
LazySortedMap<K,V>lazySortedMap(java.util.SortedMap<K,V> map, Transformer<? super K,? extends V> factory)
Factory method to create a lazily instantiated sorted map.java.util.SortedMap<K,V>
subMap(K fromKey, K toKey)
java.util.SortedMap<K,V>
tailMap(K fromKey)
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Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator
clear, containsKey, containsValue, entrySet, equals, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values
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Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap
mapIterator
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Method Detail
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lazySortedMap
public static <K,V> LazySortedMap<K,V> lazySortedMap(java.util.SortedMap<K,V> map, Factory<? extends V> factory)
Factory method to create a lazily instantiated sorted map.- Type Parameters:
K
- the key typeV
- the value type- Parameters:
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null- Returns:
- a new lazy sorted map
- Throws:
java.lang.NullPointerException
- if map or factory is null- Since:
- 4.0
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lazySortedMap
public static <K,V> LazySortedMap<K,V> lazySortedMap(java.util.SortedMap<K,V> map, Transformer<? super K,? extends V> factory)
Factory method to create a lazily instantiated sorted map.- Type Parameters:
K
- the key typeV
- the value type- Parameters:
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null- Returns:
- a new lazy sorted map
- Throws:
java.lang.NullPointerException
- if map or factory is null- Since:
- 4.0
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comparator
public java.util.Comparator<? super K> comparator()
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