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java.lang.Object | +--org.apache.commons.collections.map.Flat3Map
A Map
implementation that stores data in simple fields until
the size is greater than 3.
This map is designed for performance and can outstrip HashMap. It also has good garbage collection characteristics.
The performance gains on puts are due to not needing to create a Map Entry object. This is a large saving not only in performance but in garbage collection.
Whilst in flat mode this map is also easy for the garbage collector to dispatch. This is because it contains no complex objects or arrays which slow the progress.
Do not use Flat3Map
if the size is likely to grow beyond 3.
Inner classes inherited from class java.util.Map |
Map.Entry |
Constructor Summary | |
Flat3Map()
Constructor. |
|
Flat3Map(Map map)
Constructor copying elements from another map. |
Method Summary | |
void |
clear()
Clears the map, resetting the size to zero and nullifying references to avoid garbage collection issues. |
boolean |
containsKey(Object key)
Checks whether the map contains the specified key. |
boolean |
containsValue(Object value)
Checks whether the map contains the specified value. |
Set |
entrySet()
Gets the entrySet view of the map. |
boolean |
equals(Object obj)
Compares this map with another. |
Object |
get(Object key)
Gets the value mapped to the key specified. |
int |
hashCode()
Gets the standard Map hashCode. |
boolean |
isEmpty()
Checks whether the map is currently empty. |
Set |
keySet()
Gets the keySet view of the map. |
MapIterator |
mapIterator()
Gets an iterator over the map. |
Object |
put(Object key,
Object value)
Puts a key-value mapping into this map. |
void |
putAll(Map map)
Puts all the values from the specified map into this map. |
Object |
remove(Object key)
Removes the specified mapping from this map. |
int |
size()
Gets the size of the map. |
String |
toString()
Gets the map as a String. |
Collection |
values()
Gets the values view of the map. |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
public Flat3Map()
public Flat3Map(Map map)
map
- the map to copyMethod Detail |
public Object get(Object key)
get
in interface Map
key
- the keypublic int size()
size
in interface Map
public boolean isEmpty()
isEmpty
in interface Map
public boolean containsKey(Object key)
containsKey
in interface Map
key
- the key to search forpublic boolean containsValue(Object value)
containsValue
in interface Map
value
- the value to search forpublic Object put(Object key, Object value)
put
in interface Map
key
- the key to addvalue
- the value to addpublic void putAll(Map map)
putAll
in interface Map
map
- public Object remove(Object key)
remove
in interface Map
key
- the mapping to removepublic void clear()
clear
in interface Map
public MapIterator mapIterator()
A MapIterator returns the keys in the map. It also provides convenient methods to get the key and value, and set the value. It avoids the need to create an entrySet/keySet/values object. It also avoids creating the Map Entry object.
mapIterator
in interface IterableMap
public Set entrySet()
mapIterator()
.entrySet
in interface Map
public Set keySet()
mapIterator()
.keySet
in interface Map
public Collection values()
mapIterator()
.values
in interface Map
public boolean equals(Object obj)
equals
in interface Map
equals
in class Object
obj
- the object to compare topublic int hashCode()
hashCode
in interface Map
hashCode
in class Object
public String toString()
toString
in class Object
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