org.eclipse.persistence.indirection

Class IndirectMap<K,V>

java.lang.Object

java.util.Dictionary<K,V>

java.util.Hashtable<K,V>

org.eclipse.persistence.indirection.IndirectMap<K,V>

Type Parameters:

K - the type of keys maintained by this map

V - the type of mapped values

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<K,V>, ChangeTracker, CollectionChangeTracker, IndirectCollection, IndirectContainer

public class IndirectMap<K,V>
extends java.util.Hashtable<K,V>
implements CollectionChangeTracker, IndirectCollection

IndirectMap allows a domain class to take advantage of TopLink indirection without having to declare its instance variable as a ValueHolderInterface.

To use an IndirectMap:

• Declare the appropriate instance variable with type Map or Hashtable
• Send the message #useTransparentMap(String) to the appropriate CollectionMapping.

EclipseLink will place an IndirectMap in the instance variable when the containing domain object is read from the datatabase. With the first message sent to the IndirectMap, the contents are fetched from the database and normal Hashtable/Map behavior is resumed.

See Also:

CollectionMapping, IndirectList, Serialized Form

Author:

Big Country

Since:

TOPLink/Java 2.5

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Hashtable<K,V>	delegate Reduce type casting
protected int	initialCapacity Store initial size for lazy init.
protected float	loadFactor Store load factor for lazy init.
protected ValueHolderInterface	valueHolder Delegate indirection behavior to a value holder

Constructor Summary

Constructors

Constructor and Description
IndirectMap() PUBLIC: Construct a new, empty IndirectMap with a default capacity and load factor.
IndirectMap(int initialCapacity) PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and default load factor.
IndirectMap(int initialCapacity, float loadFactor) PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and load factor.
IndirectMap(java.util.Map<? extends K,? extends V> m) PUBLIC: Construct a new IndirectMap with the same mappings as the given Map.

Method Summary

Modifier and Type	Method and Description
java.beans.PropertyChangeListener	_persistence_getPropertyChangeListener() Return the property change listener for change tracking.
void	_persistence_setPropertyChangeListener(java.beans.PropertyChangeListener changeListener) INTERNAL: Set the property change listener for change tracking.
protected java.util.Hashtable<K,V>	buildDelegate() Return the freshly-built delegate.
void	clear()
void	clearDeferredChanges() INTERNAL: clear any changes that have been deferred to instantiation.
java.lang.Object	clone()
boolean	contains(java.lang.Object value)
boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
java.util.Enumeration<V>	elements()
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
boolean	equals(java.lang.Object o)
V	get(java.lang.Object key)
java.util.Collection	getAddedElements() INTERNAL: Return the elements that have been added before instantiation.
protected java.util.Hashtable<K,V>	getDelegate() INTERNAL: Check whether the contents have been read from the database.
java.lang.Object	getDelegateObject() INTERNAL: Return the real collection object.
java.util.Collection	getRemovedElements() INTERNAL: Return the elements that have been removed before instantiation.
java.lang.String	getTrackedAttributeName() INTERNAL: Return the mapping attribute name, used to raise change events.
ValueHolderInterface	getValueHolder() PUBLIC: Return the valueHolder.
boolean	hasDeferredChanges() INTERNAL: Return if any elements that have been added or removed before instantiation.
int	hashCode()
boolean	hasTrackedPropertyChangeListener() INTERNAL: Return if the collection has a property change listener for change tracking.
protected void	initialize(int initialCapacity, float loadFactor) Initialize the instance.
protected void	initialize(java.util.Map<? extends K,? extends V> m) Initialize the instance.
boolean	isEmpty()
boolean	isInstantiated() PUBLIC: Return whether the contents have been read from the database.
java.util.Enumeration<K>	keys()
java.util.Set<K>	keySet()
V	put(K key, V value)
void	putAll(java.util.Map<? extends K,? extends V> t)
protected void	raiseAddChangeEvent(java.lang.Object key, java.lang.Object value) Raise the add change event and relationship maintainence.
protected void	raiseRemoveChangeEvent(java.lang.Object key, java.lang.Object value) Raise the remove change event.
protected void	rehash()
V	remove(java.lang.Object key)
void	setTrackedAttributeName(java.lang.String attributeName) INTERNAL: Set the mapping attribute name, used to raise change events.
void	setUseLazyInstantiation(boolean useLazyInstantiation) INTERNAL Set whether this collection should attempt do deal with adds and removes without retrieving the collection from the dB
void	setValueHolder(ValueHolderInterface valueHolder) INTERNAL: Set the value holder.
int	size()
java.lang.String	toString() PUBLIC: Use the Hashtable.toString(); but wrap it with braces to indicate there is a bit of indirection.
java.util.Collection<V>	values()

Methods inherited from class java.util.Hashtable

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Methods inherited from class java.lang.Object

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

Field Detail

delegate

protected volatile java.util.Hashtable<K,V> delegate

Reduce type casting

valueHolder

protected ValueHolderInterface valueHolder

Delegate indirection behavior to a value holder

initialCapacity

protected int initialCapacity

Store initial size for lazy init.

loadFactor

protected float loadFactor

Store load factor for lazy init.

Constructor Detail

IndirectMap

public IndirectMap()

PUBLIC: Construct a new, empty IndirectMap with a default capacity and load factor.

IndirectMap

public IndirectMap(int initialCapacity)

PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and default load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable

IndirectMap

public IndirectMap(int initialCapacity,
                   float loadFactor)

PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable

loadFactor - a number between 0.0 and 1.0

Throws:

java.lang.IllegalArgumentException - if the initial capacity is less than or equal to zero, or if the load factor is less than or equal to zero

IndirectMap

public IndirectMap(java.util.Map<? extends K,? extends V> m)

PUBLIC: Construct a new IndirectMap with the same mappings as the given Map. The IndirectMap is created with a capacity of twice the number of entries in the given Map or 11 (whichever is greater), and a default load factor, which is 0.75.

Parameters:

m - a map containing the mappings to use

Method Detail

buildDelegate

protected java.util.Hashtable<K,V> buildDelegate()

Return the freshly-built delegate.

clear

public void clear()

Specified by:

clear in interface java.util.Map<K,V>

Overrides:

clear in class java.util.Hashtable<K,V>

See Also:

Hashtable.clear()

clearDeferredChanges

public void clearDeferredChanges()

INTERNAL: clear any changes that have been deferred to instantiation. Indirect collections with change tracking avoid instantiation on add/remove.

Specified by:

clearDeferredChanges in interface IndirectCollection

clone

public java.lang.Object clone()

Overrides:

clone in class java.util.Hashtable<K,V>

See Also:

This will result in a database query if necessary.

contains

public boolean contains(java.lang.Object value)

Overrides:

contains in class java.util.Hashtable<K,V>

See Also:

Hashtable.contains(java.lang.Object)

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<K,V>

Overrides:

containsKey in class java.util.Hashtable<K,V>

See Also:

Hashtable.containsKey(java.lang.Object)

containsValue

public boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map<K,V>

Overrides:

containsValue in class java.util.Hashtable<K,V>

See Also:

Hashtable.containsValue(java.lang.Object)

elements

public java.util.Enumeration<V> elements()

Overrides:

elements in class java.util.Hashtable<K,V>

See Also:

Hashtable.elements()

entrySet

public java.util.Set<java.util.Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface java.util.Map<K,V>

Overrides:

entrySet in class java.util.Hashtable<K,V>

See Also:

Hashtable.entrySet()

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map<K,V>

Overrides:

equals in class java.util.Hashtable<K,V>

See Also:

Hashtable.equals(java.lang.Object)

get

public V get(java.lang.Object key)

Specified by:

get in interface java.util.Map<K,V>

Overrides:

get in class java.util.Hashtable<K,V>

See Also:

Hashtable.get(java.lang.Object)

getDelegate

protected java.util.Hashtable<K,V> getDelegate()

INTERNAL: Check whether the contents have been read from the database. If they have not, read them and set the delegate. This method used to be synchronized, which caused deadlock.

getDelegateObject

public java.lang.Object getDelegateObject()

INTERNAL: Return the real collection object. This will force instantiation.

Specified by:

getDelegateObject in interface IndirectCollection

getTrackedAttributeName

public java.lang.String getTrackedAttributeName()

INTERNAL: Return the mapping attribute name, used to raise change events.

Specified by:

getTrackedAttributeName in interface CollectionChangeTracker

_persistence_getPropertyChangeListener

public java.beans.PropertyChangeListener _persistence_getPropertyChangeListener()

Return the property change listener for change tracking.

Specified by:

_persistence_getPropertyChangeListener in interface ChangeTracker

getValueHolder

public ValueHolderInterface getValueHolder()

PUBLIC: Return the valueHolder. This method used to be synchronized, which caused deadlock.

Specified by:

getValueHolder in interface IndirectContainer

Returns:

org.eclipse.persistence.indirection.ValueHolderInterface A representation of the valueholder * which this container uses

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map<K,V>

Overrides:

hashCode in class java.util.Hashtable<K,V>

See Also:

Hashtable.hashCode()

hasTrackedPropertyChangeListener

public boolean hasTrackedPropertyChangeListener()

INTERNAL: Return if the collection has a property change listener for change tracking.

initialize

protected void initialize(int initialCapacity,
                          float loadFactor)

Initialize the instance.

initialize

protected void initialize(java.util.Map<? extends K,? extends V> m)

Initialize the instance.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<K,V>

Overrides:

isEmpty in class java.util.Hashtable<K,V>

See Also:

Hashtable.isEmpty()

isInstantiated

public boolean isInstantiated()

PUBLIC: Return whether the contents have been read from the database.

Specified by:

isInstantiated in interface IndirectContainer

keys

public java.util.Enumeration<K> keys()

Overrides:

keys in class java.util.Hashtable<K,V>

See Also:

Hashtable.keys()

keySet

public java.util.Set<K> keySet()

Specified by:

keySet in interface java.util.Map<K,V>

Overrides:

keySet in class java.util.Hashtable<K,V>

See Also:

Hashtable.keySet()

put

public V put(K key,
             V value)

Specified by:

put in interface java.util.Map<K,V>

Overrides:

put in class java.util.Hashtable<K,V>

See Also:

Hashtable.put(java.lang.Object, java.lang.Object)

putAll

public void putAll(java.util.Map<? extends K,? extends V> t)

Specified by:

putAll in interface java.util.Map<K,V>

Overrides:

putAll in class java.util.Hashtable<K,V>

See Also:

Hashtable.putAll(java.util.Map)

rehash

protected void rehash()

Overrides:

rehash in class java.util.Hashtable<K,V>

See Also:

Hashtable.rehash()

raiseAddChangeEvent

protected void raiseAddChangeEvent(java.lang.Object key,
                                   java.lang.Object value)

Raise the add change event and relationship maintainence.

raiseRemoveChangeEvent

protected void raiseRemoveChangeEvent(java.lang.Object key,
                                      java.lang.Object value)

Raise the remove change event.

remove

public V remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map<K,V>

Overrides:

remove in class java.util.Hashtable<K,V>

See Also:

Hashtable.remove(java.lang.Object)

setTrackedAttributeName

public void setTrackedAttributeName(java.lang.String attributeName)

INTERNAL: Set the mapping attribute name, used to raise change events. This is required if the change listener is set.

Specified by:

setTrackedAttributeName in interface CollectionChangeTracker

_persistence_setPropertyChangeListener

public void _persistence_setPropertyChangeListener(java.beans.PropertyChangeListener changeListener)

INTERNAL: Set the property change listener for change tracking.

Specified by:

_persistence_setPropertyChangeListener in interface ChangeTracker

setValueHolder

public void setValueHolder(ValueHolderInterface valueHolder)

INTERNAL: Set the value holder.

Specified by:

setValueHolder in interface IndirectContainer

size

public int size()

Specified by:

size in interface java.util.Map<K,V>

Overrides:

size in class java.util.Hashtable<K,V>

See Also:

Hashtable.size()

setUseLazyInstantiation

public void setUseLazyInstantiation(boolean useLazyInstantiation)

INTERNAL Set whether this collection should attempt do deal with adds and removes without retrieving the collection from the dB

Specified by:

setUseLazyInstantiation in interface IndirectCollection

getRemovedElements

public java.util.Collection getRemovedElements()

INTERNAL: Return the elements that have been removed before instantiation.

Specified by:

getRemovedElements in interface IndirectCollection

getAddedElements

public java.util.Collection getAddedElements()

INTERNAL: Return the elements that have been added before instantiation.

Specified by:

getAddedElements in interface IndirectCollection

hasDeferredChanges

public boolean hasDeferredChanges()

INTERNAL: Return if any elements that have been added or removed before instantiation.

Specified by:

hasDeferredChanges in interface IndirectCollection

toString

public java.lang.String toString()

PUBLIC: Use the Hashtable.toString(); but wrap it with braces to indicate there is a bit of indirection. Don't allow this method to trigger a database read.

Overrides:

toString in class java.util.Hashtable<K,V>

See Also:

Hashtable.toString()

values

public java.util.Collection<V> values()

Specified by:

values in interface java.util.Map<K,V>

Overrides:

values in class java.util.Hashtable<K,V>

See Also:

Hashtable.values()