com.triactive.jdo.util
Class SoftValueMap

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

All Implemented Interfaces:

java.util.Map

public class SoftValueMap

extends com.triactive.jdo.util.ReferenceValueMap

A java.util.Map implementation with soft values.

The values are stored as soft references. If map entry value object is not actively being used, i.e. no other object has a strong reference to it, it may become garbage collected at the discretion of the garbage collector (typically if the VM is low on memory). If this happens, the entry in the SoftValueMap corresponding to the value object will also be removed.

Author:

Mike Martin

See Also:

SoftReference

Nested Class Summary

Nested classes inherited from class java.util.Map

java.util.Map.Entry

Field Summary

protected java.lang.ref.ReferenceQueue

refQueue

Constructor Summary

SoftValueMap()

SoftValueMap(int initialCapacity)

SoftValueMap(int initialCapacity, float loadFactor)

SoftValueMap(java.util.Map m)

Method Summary

boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
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 java.lang.ref.Reference	newReference(java.lang.Object value) Returns a new Reference object to be inserted into the map.
java.lang.Object	put(java.lang.Object key, java.lang.Object value)
java.lang.Object	remove(java.lang.Object key)
int	size()
java.lang.String	toString()
java.util.Collection	values()

Methods inherited from class java.util.AbstractMap

clear, clone, putAll

Methods inherited from class java.lang.Object

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

Field Detail

refQueue

protected final java.lang.ref.ReferenceQueue refQueue

Constructor Detail

SoftValueMap

public SoftValueMap()

SoftValueMap

public SoftValueMap(int initialCapacity)

SoftValueMap

public SoftValueMap(int initialCapacity,
                    float loadFactor)

SoftValueMap

public SoftValueMap(java.util.Map m)

Method Detail

newReference

protected java.lang.ref.Reference newReference(java.lang.Object value)

Description copied from class: com.triactive.jdo.util.ReferenceValueMap

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:

value - The associated value to be referenced.

Returns:

A new Reference object to be inserted into the map.

put

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

get

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

size

public int size()

isEmpty

public boolean isEmpty()

containsKey

public boolean containsKey(java.lang.Object key)

containsValue

public boolean containsValue(java.lang.Object value)

keySet

public java.util.Set keySet()

values

public java.util.Collection values()

entrySet

public java.util.Set entrySet()

remove

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

hashCode

public int hashCode()

equals

public boolean equals(java.lang.Object o)

toString

public java.lang.String toString()