Class FixedSizeMap
- All Implemented Interfaces:
Serializable
,Map
,BoundedMap
Map
to fix the size, preventing add/remove.
Any action that would change the size of the map is disallowed. The put method is allowed to change the value associated with an existing key however.
If trying to remove or clear the map, an UnsupportedOperationException is thrown. If trying to put a new mapping into the map, an IllegalArgumentException is thrown. This is because the put method can succeed if the mapping's key already exists in the map, so the put method is not always unsupported.
Note that FixedSizeMap 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.synchronizedMap(Map)
. 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 14:33:15 +0200 (Thu, 10 Apr 2008) $
- See Also:
-
Nested Class Summary
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final long
Serialization versionFields inherited from class org.apache.commons.collections.map.AbstractMapDecorator
map
-
Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
FixedSizeMap
(Map map) Constructor that wraps (not copies). -
Method Summary
Modifier and TypeMethodDescriptionvoid
clear()
static Map
Factory method to create a fixed size map.entrySet()
boolean
isFull()
Returns true if this map is full and no new elements can be added.keySet()
int
maxSize()
Gets the maximum size of the map (the bound).void
private void
Read the map in using a custom routine.values()
private void
Write the map out using a custom routine.Methods inherited from class org.apache.commons.collections.map.AbstractMapDecorator
containsKey, containsValue, equals, get, getMap, hashCode, isEmpty, size, toString
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, equals, forEach, get, getOrDefault, hashCode, isEmpty, merge, putIfAbsent, remove, replace, replace, replaceAll, size
-
Field Details
-
serialVersionUID
private static final long serialVersionUIDSerialization version- See Also:
-
-
Constructor Details
-
FixedSizeMap
Constructor that wraps (not copies).- Parameters:
map
- the map to decorate, must not be null- Throws:
IllegalArgumentException
- if map is null
-
-
Method Details
-
decorate
Factory method to create a fixed size map.- Parameters:
map
- the map to decorate, must not be null- Throws:
IllegalArgumentException
- if map is null
-
writeObject
Write the map out using a custom routine.- Parameters:
out
- the output stream- Throws:
IOException
- Since:
- Commons Collections 3.1
-
readObject
Read the map in using a custom routine.- Parameters:
in
- the input stream- Throws:
IOException
ClassNotFoundException
- Since:
- Commons Collections 3.1
-
put
- Specified by:
put
in interfaceMap
- Overrides:
put
in classAbstractMapDecorator
-
putAll
- Specified by:
putAll
in interfaceMap
- Overrides:
putAll
in classAbstractMapDecorator
-
clear
public void clear()- Specified by:
clear
in interfaceMap
- Overrides:
clear
in classAbstractMapDecorator
-
remove
- Specified by:
remove
in interfaceMap
- Overrides:
remove
in classAbstractMapDecorator
-
entrySet
- Specified by:
entrySet
in interfaceMap
- Overrides:
entrySet
in classAbstractMapDecorator
-
keySet
- Specified by:
keySet
in interfaceMap
- Overrides:
keySet
in classAbstractMapDecorator
-
values
- Specified by:
values
in interfaceMap
- Overrides:
values
in classAbstractMapDecorator
-
isFull
public boolean isFull()Description copied from interface:BoundedMap
Returns true if this map is full and no new elements can be added.- Specified by:
isFull
in interfaceBoundedMap
- Returns:
true
if the map is full
-
maxSize
public int maxSize()Description copied from interface:BoundedMap
Gets the maximum size of the map (the bound).- Specified by:
maxSize
in interfaceBoundedMap
- Returns:
- the maximum number of elements the map can hold
-