com.ibm.icu.impl

Class SoftCache<K,V,D>

java.lang.Object

com.ibm.icu.impl.CacheBase<K,V,D>

com.ibm.icu.impl.SoftCache<K,V,D>

Type Parameters:

K - Cache lookup key type

V - Cache instance value type

D - Data type for creating a new instance value

public abstract class SoftCache<K,V,D>
extends CacheBase<K,V,D>

Generic, thread-safe cache implementation, storing SoftReferences to cached instances. To use, instantiate a subclass which implements the createInstance() method, and call get() with the key and the data. The get() call will use the data only if it needs to call createInstance(), otherwise the data is ignored. By using SoftReferences to instances, the Java runtime can release instances once they are not used any more at all. If such an instance is then requested again, the get() method will call createInstance() again and also create a new SoftReference. The cache holds on to its map of keys to SoftReferenced instances forever.

Constructor Summary

Constructors

Constructor and Description
SoftCache()

Method Summary

Modifier and Type	Method and Description
V	getInstance(K key, D data) Retrieves an instance from the cache.

Methods inherited from class com.ibm.icu.impl.CacheBase

createInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

SoftCache

public SoftCache()

Method Detail

getInstance

public final V getInstance(K key,
                           D data)

Description copied from class: CacheBase

Retrieves an instance from the cache. Calls createInstance(key, data) if the cache does not already contain an instance with this key. Ignores data if the cache already contains an instance with this key.

Specified by:

getInstance in class CacheBase<K,V,D>

Parameters:

key - Cache lookup key for the requested instance

data - Data for createInstance() if the instance is not already cached

Returns:

The requested instance