org.springframework.util
Class CachingMapDecorator

java.lang.Object
  extended by org.springframework.util.CachingMapDecorator
All Implemented Interfaces:
Serializable, Map

public abstract class CachingMapDecorator
extends Object
implements Map, Serializable

A simple decorator for a Map, encapsulating the workflow for caching expensive values in a target Map. Supports caching weak or strong keys.

This class is also an abstract template. Caching Map implementations should subclass and override the create(key) method which encapsulates expensive creation of a new object.

Since:
1.2.2
Author:
Keith Donald
See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from interface java.util.Map
Map.Entry<K,V>
 
Constructor Summary
CachingMapDecorator()
          Create a CachingMapDecorator with strong keys.
CachingMapDecorator(boolean weakKeys)
          Create a CachingMapDecorator.
CachingMapDecorator(boolean weakKeys, int size)
          Create a CachingMapDecorator with initial size.
CachingMapDecorator(Map targetMap)
          Create a CachingMapDecorator for the given Map.
 
Method Summary
 void clear()
           
 boolean containsKey(Object key)
           
 boolean containsValue(Object value)
           
protected abstract  Object create(Object key)
          Create a value to cache for the given key.
 Set entrySet()
           
 Object get(Object key)
          Get value for key.
 boolean isEmpty()
           
 Set keySet()
           
 Object put(Object key, Object value)
           
 void putAll(Map t)
           
 Object remove(Object key)
           
 int size()
           
 String toString()
           
 Collection values()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.Map
equals, hashCode
 

Constructor Detail

CachingMapDecorator

public CachingMapDecorator()
Create a CachingMapDecorator with strong keys.


CachingMapDecorator

public CachingMapDecorator(boolean weakKeys)
Create a CachingMapDecorator.

Parameters:
weakKeys - whether to use weak references for keys

CachingMapDecorator

public CachingMapDecorator(boolean weakKeys,
                           int size)
Create a CachingMapDecorator with initial size.

Parameters:
weakKeys - whether to use weak references for keys
size - the initial cache size

CachingMapDecorator

public CachingMapDecorator(Map targetMap)
Create a CachingMapDecorator for the given Map.

Parameters:
targetMap - the Map to decoarate
Method Detail

size

public int size()
Specified by:
size in interface Map

isEmpty

public boolean isEmpty()
Specified by:
isEmpty in interface Map

containsKey

public boolean containsKey(Object key)
Specified by:
containsKey in interface Map

containsValue

public boolean containsValue(Object value)
Specified by:
containsValue in interface Map

put

public Object put(Object key,
                  Object value)
Specified by:
put in interface Map

remove

public Object remove(Object key)
Specified by:
remove in interface Map

putAll

public void putAll(Map t)
Specified by:
putAll in interface Map

clear

public void clear()
Specified by:
clear in interface Map

keySet

public Set keySet()
Specified by:
keySet in interface Map

values

public Collection values()
Specified by:
values in interface Map

entrySet

public Set entrySet()
Specified by:
entrySet in interface Map

get

public Object get(Object key)
Get value for key. Creates and caches value if it doesn't already exist in the cache.

Specified by:
get in interface Map
See Also:
create(Object)

create

protected abstract Object create(Object key)
Create a value to cache for the given key. Called by get if there is no value cached already.

Parameters:
key - the cache key
See Also:
get(Object)

toString

public String toString()
Overrides:
toString in class Object


Copyright (c) 2002-2005 The Spring Framework Project.