Package org.intermine.util

Class WeakReferenceMap<K,V>

java.lang.Object

org.intermine.util.ReferenceMap<K,V>

org.intermine.util.WeakReferenceMap<K,V>

Type Parameters:

K - the type of keys maintained by this map

V - the type of mapped values

All Implemented Interfaces:

java.util.Map<K,V>

Direct Known Subclasses:

WeakReferenceHashMap

public abstract class WeakReferenceMap<K,V>
extends ReferenceMap<K,V>

This is a Map implementation designed specifically for people intending to create a cache. The keys are held strongly, but the values are held weakly, so the values can be garbage-collected. When an entry is garbage-collected, its key is removed from the Map on the next Map activity. Subclasses of this map are required to provide the actual Map functionality.

The entrySet() and values() methods of this class do not work.

Author:

Matthew Wakeling

See Also:

WeakReference

Nested Class Summary

Nested classes/interfaces inherited from class org.intermine.util.ReferenceMap

ReferenceMap.ReferenceWithKey<K>

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K extends java.lang.Object,V extends java.lang.Object>

Field Summary

Fields inherited from class org.intermine.util.ReferenceMap

name, NULL_VALUE, queue, subMap

Constructor Summary

Constructors

Constructor	Description
WeakReferenceMap()

Method Summary

Modifier and Type	Method	Description
protected org.intermine.util.WeakReferenceMap.WeakReferenceWithKey<K>	newRef(java.lang.Object value, java.lang.ref.ReferenceQueue<java.lang.Object> queue, K key)	Returns a new WeakReferenceWithKey object for the given objects.

Methods inherited from class org.intermine.util.ReferenceMap

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values

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, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

WeakReferenceMap

public WeakReferenceMap()

Method Detail

newRef

protected org.intermine.util.WeakReferenceMap.WeakReferenceWithKey<K> newRef(java.lang.Object value,
                                                                             java.lang.ref.ReferenceQueue<java.lang.Object> queue,
                                                                             K key)

Returns a new WeakReferenceWithKey object for the given objects.

Specified by:

newRef in class ReferenceMap<K,V>

Parameters:

value - an Object

queue - a ReferenceQueue

key - an Object

Returns:

a WeakReferenceWithKey object