Package org.exoplatform.services.cache.future

Class FutureCache<K,V,C>

java.lang.Object

org.exoplatform.services.cache.future.FutureCache<K,V,C>

Type Parameters:

K - the key type parameter

V - the value type parameter

C - the context type parameter

Direct Known Subclasses:

FutureExoCache

public abstract class FutureCache<K,V,C>
extends Object

A future cache that prevents the loading of the same resource twice. This should be used when the resource to load is very expensive or cannot be concurrently retrieved (like a classloading).

Version:

$Revision$

Author:

Julien Viet

Constructor Summary

Constructors

Constructor	Description
FutureCache(Loader<K,V,C> loader)

Method Summary

Modifier and Type	Method	Description
final V	get(C context, K key)	Perform a cache lookup for the specified key within the specified context.
protected abstract V	get(K key)
protected abstract void	put(K key, V value)
protected abstract void	putOnly(K key, V value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FutureCache

public FutureCache(Loader<K,V,C> loader)

Method Details

get

protected abstract V get(K key)

put

protected abstract void put(K key,
 V value)

putOnly

protected abstract void putOnly(K key,
 V value)

get

public final V get(C context,
 K key)

Perform a cache lookup for the specified key within the specified context. When the value cannot be loaded (because it does not exist or it failed or anything else that does not come to my mind), the value null is returned.

Parameters:

context - the context in which the resource is accessed

key - the key identifying the resource

Returns:

the value