com.triactive.jdo.util
Class ReferenceValueMap

java.lang.Object
  com.triactive.jdo.util.ReferenceValueMap

All Implemented Interfaces:

java.lang.Cloneable, java.util.Map

Direct Known Subclasses:

SoftValueMap, WeakValueMap

public abstract class ReferenceValueMap

extends java.lang.Object

implements java.util.Map, java.lang.Cloneable

A java.util.Map implementation using reference values.

The values are stored in the map as references. If the garbage collector clears the reference, the corresponding key is automatically removed from the map.

Author:

Mike Martin

See Also:

Reference

Nested Class Summary

static interface

ReferenceValueMap.ValueReference References returned by newValueReference must implement this interface to provide the corresponding map key for the value.

Nested classes inherited from class java.util.Map

java.util.Map.Entry

Constructor Summary

ReferenceValueMap()

ReferenceValueMap(int initialCapacity)

ReferenceValueMap(int initialCapacity, float loadFactor)

ReferenceValueMap(java.util.Map m)

Method Summary

void	clear()
java.lang.Object	clone()
boolean	containsKey(java.lang.Object obj)
boolean	containsValue(java.lang.Object obj)
java.util.Set	entrySet()
boolean	equals(java.lang.Object o)
java.lang.Object	get(java.lang.Object key)
int	hashCode()
boolean	isEmpty()
java.util.Set	keySet()
protected abstract ReferenceValueMap.ValueReference	newValueReference(java.lang.Object key, java.lang.Object value, java.lang.ref.ReferenceQueue queue) Returns a new Reference object to be inserted into the map.
java.lang.Object	put(java.lang.Object key, java.lang.Object value)
void	putAll(java.util.Map m)
void	reap()
java.lang.Object	remove(java.lang.Object key)
int	size()
java.util.Collection	values()

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReferenceValueMap

public ReferenceValueMap()

ReferenceValueMap

public ReferenceValueMap(int initialCapacity)

ReferenceValueMap

public ReferenceValueMap(int initialCapacity,
                         float loadFactor)

ReferenceValueMap

public ReferenceValueMap(java.util.Map m)

Method Detail

clone

public java.lang.Object clone()

newValueReference

protected abstract ReferenceValueMap.ValueReference newValueReference(java.lang.Object key,
                                                                      java.lang.Object value,
                                                                      java.lang.ref.ReferenceQueue queue)

Returns a new Reference object to be inserted into the map. Subclasses must implement this method to construct Reference objects of the desired type (e.g. SoftReference, etc.).

Parameters:

key - The key that will be inserted.

value - The associated value to be referenced.

queue - The ReferenceQueue with which to register the new Reference object.

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Specified by:

put in interface java.util.Map

putAll

public void putAll(java.util.Map m)

Specified by:

putAll in interface java.util.Map

get

public java.lang.Object get(java.lang.Object key)

Specified by:

get in interface java.util.Map

clear

public void clear()

Specified by:

clear in interface java.util.Map

size

public int size()

Specified by:

size in interface java.util.Map

containsKey

public boolean containsKey(java.lang.Object obj)

Specified by:

containsKey in interface java.util.Map

containsValue

public boolean containsValue(java.lang.Object obj)

Specified by:

containsValue in interface java.util.Map

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map

keySet

public java.util.Set keySet()

Specified by:

keySet in interface java.util.Map

values

public java.util.Collection values()

Specified by:

values in interface java.util.Map

entrySet

public java.util.Set entrySet()

Specified by:

entrySet in interface java.util.Map

remove

public java.lang.Object remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map

reap

public void reap()