org.pojomatic.internal
Class SelfPopulatingMap<K,V>

java.lang.Object
  org.pojomatic.internal.SelfPopulatingMap<K,V>

public abstract class SelfPopulatingMap<K,V>
extends java.lang.Object

A thread-safe "map" which generates values on demand, with the guarantee that no more than one value will be auto-created for a given key. Classes extending this class should override create(Object).

Constructor Summary

SelfPopulatingMap()

Method Summary

protected abstract V	create(K key) Create a value for a key.
V	get(K key)

Methods inherited from class java.lang.Object

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

Constructor Detail

SelfPopulatingMap

public SelfPopulatingMap()

Method Detail

get

public V get(K key)

create

protected abstract V create(K key)

Create a value for a key. This will be called by get(Object) when there is not already an existing value, and no other thread is already creating a value for that key. The value returned must not be null.

Parameters:

key - the key to create the value for

Returns:

the value