Class Map<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.datanucleus.store.types.wrappers.Map<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>, SCO<Map<K,V>>, SCOContainer<Map<K,V>>, SCOMap<Map<K,V>,K,V>

Direct Known Subclasses:

Map

public class Map<K,V>
extends AbstractMap<K,V>
implements SCOMap<Map<K,V>,K,V>, Cloneable, Serializable

A mutable second-class Map object. This is the simplified form that intercepts mutators and marks the field as dirty. It also handles cascade-delete triggering for persistable elements.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
protected Map<K,V>	delegate	The internal "delegate".
protected AbstractMemberMetaData	ownerMmd
protected DNStateManager	ownerSM

Constructor Summary

Constructors

Constructor	Description
Map(DNStateManager sm, AbstractMemberMetaData mmd)	Constructor, using StateManager of the "owner" and the field name.

Method Summary

Modifier and Type	Method	Description
void	attachCopy(Map value)	Method to return an attached copy of the passed (detached) value.
void	clear()	Method to clear the Map.
Object	clone()	Creates and returns a copy of this object.
boolean	containsKey(Object key)	Utility to check if a key is contained in the Map.
boolean	containsValue(Object value)	Utility to check if a value is contained in the Map.
Map	detachCopy(FetchPlanState state)	Method to return a detached copy of the container.
Set	entrySet()	Accessor for the set of entries in the Map.
boolean	equals(Object o)	Method to check the equality of this map, and another.
void	forEach(BiConsumer<? super K, ? super V> action)
V	get(Object key)	Accessor for the value stored against a key.
String	getFieldName()	Accessor for the field name.
Object	getOwner()	Accessor for the owner.
Map	getValue()	Accessor for the unwrapped value that we are wrapping.
int	hashCode()	Method to generate a hashcode for this Map.
void	initialise()	Method to initialise the SCO for use, and allowing the SCO to be loaded from the datastore (when we have a backing store).
void	initialise(Map m)	Method to initialise the SCO for use with the provided initial value.
void	initialise(Map newValue, Object oldValue)	Method to initialise the SCO for use, where replacing an old value with a new value such as when calling a setter field passing in a new value.
boolean	isEmpty()	Method to return if the Map is empty.
boolean	isLoaded()	Method to return if the SCO has its contents loaded.
Set<K>	keySet()	Accessor for the set of keys in the Map.
void	load()	Method to effect the load of the data in the SCO.
void	makeDirty()	Utility to mark the object as dirty
V	put(K key, V value)	Method to add a value to the Map.
void	putAll(Map m)	Method to add a Map of values to this map.
V	remove(Object key)	Method to remove a value from the Map.
void	setValue(Map value)	Method to change the delegate value this wraps (to save recreating the wrapper).
int	size()	Method to return the size of the Map.
void	unsetOwner()	Method to unset the owner and field information.
void	updateEmbeddedKey(K key, int fieldNumber, Object newValue, boolean makeDirty)	Method to update an embedded key in this map.
void	updateEmbeddedValue(V value, int fieldNumber, Object newValue, boolean makeDirty)	Method to update an embedded value in this map.
Collection<V>	values()	Accessor for the set of values in the Map.
protected Object	writeReplace()	The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream.

Methods inherited from class AbstractMap

toString

Methods inherited from class Object

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

Methods inherited from interface Map

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

Field Details

ownerSM

protected transient DNStateManager ownerSM

ownerMmd

protected transient AbstractMemberMetaData ownerMmd

delegate

protected Map<K,V> delegate

The internal "delegate".

Constructor Details

Map

public Map(DNStateManager sm,
 AbstractMemberMetaData mmd)

Constructor, using StateManager of the "owner" and the field name.

Parameters:

sm - The owner StateManager

mmd - Metadata for the member

Method Details

initialise

public void initialise(Map newValue,
 Object oldValue)

Description copied from interface: SCO

Method to initialise the SCO for use, where replacing an old value with a new value such as when calling a setter field passing in a new value. Note that oldValue is marked as Object since for cases where the member type is Collection the newValue could be, for example, ArrayList, and the oldValue of type Collection (representing null).

Specified by:

initialise in interface SCO<K>

Parameters:

newValue - New value (to wrap)

oldValue - Old value (to use in deciding what needs deleting etc)

initialise

public void initialise(Map m)

Description copied from interface: SCO

Method to initialise the SCO for use with the provided initial value. This is used, for example, when retrieving the field from the datastore and setting it in the persistable object.

Specified by:

initialise in interface SCO<K>

Parameters:

m - the object from which to copy the value.

initialise

public void initialise()

Description copied from interface: SCO

Method to initialise the SCO for use, and allowing the SCO to be loaded from the datastore (when we have a backing store). This can be utilised to perform any eager loading of information from the datastore.

Specified by:

initialise in interface SCO<K>

getValue

public Map getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO<K>

Returns:

The unwrapped value

setValue

public void setValue(Map value)

Description copied from interface: SCOContainer

Method to change the delegate value this wraps (to save recreating the wrapper).

Specified by:

setValue in interface SCOContainer<K>

Parameters:

value - The new value

load

public void load()

Method to effect the load of the data in the SCO. Used when the SCO supports lazy-loading to tell it to load all now.

Specified by:

load in interface SCOContainer<K>

isLoaded

public boolean isLoaded()

Method to return if the SCO has its contents loaded. Returns true.

Specified by:

isLoaded in interface SCOContainer<K>

Returns:

Whether it is loaded

updateEmbeddedKey

public void updateEmbeddedKey(K key,
 int fieldNumber,
 Object newValue,
 boolean makeDirty)

Method to update an embedded key in this map.

Specified by:

updateEmbeddedKey in interface SCOMap<Map<K,V>,K,V>

Parameters:

key - The key

fieldNumber - Number of field in the key

newValue - New value for this field

makeDirty - Whether to make the SCO field dirty.

updateEmbeddedValue

public void updateEmbeddedValue(V value,
 int fieldNumber,
 Object newValue,
 boolean makeDirty)

Method to update an embedded value in this map.

Specified by:

updateEmbeddedValue in interface SCOMap<Map<K,V>,K,V>

Parameters:

value - The value

fieldNumber - Number of field in the value

newValue - New value for this field

makeDirty - Whether to make the SCO field dirty.

getFieldName

public String getFieldName()

Accessor for the field name.

Specified by:

getFieldName in interface SCO<K>

Returns:

The field name.

getOwner

public Object getOwner()

Accessor for the owner.

Specified by:

getOwner in interface SCO<K>

Returns:

The owner.

unsetOwner

public void unsetOwner()

Method to unset the owner and field information.

Specified by:

unsetOwner in interface SCO<K>

makeDirty

public void makeDirty()

Utility to mark the object as dirty

detachCopy

public Map detachCopy(FetchPlanState state)

Method to return a detached copy of the container. Recurse sthrough the keys/values so that they are likewise detached.

Specified by:

detachCopy in interface SCO<K>

Parameters:

state - State for detachment process

Returns:

The detached container

attachCopy

public void attachCopy(Map value)

Method to return an attached copy of the passed (detached) value. The returned attached copy is a SCO wrapper. Goes through the existing keys/values in the store for this owner field and removes ones no longer present, and adds new keys/values. All keys/values in the (detached) value are attached.

Specified by:

attachCopy in interface SCO<K>

Parameters:

value - The new (map) value

clone

public Object clone()

Creates and returns a copy of this object.

Mutable second-class Objects are required to provide a public clone method in order to allow for copying persistable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.

Specified by:

clone in interface SCO<K>

Overrides:

clone in class AbstractMap<K,V>

Returns:

Clone of the object

containsKey

public boolean containsKey(Object key)

Utility to check if a key is contained in the Map.

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

Parameters:

key - The key to check

Returns:

Whether it is contained

containsValue

public boolean containsValue(Object value)

Utility to check if a value is contained in the Map.

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue in class AbstractMap<K,V>

Parameters:

value - The value to check

Returns:

Whether it is contained

entrySet

public Set entrySet()

Accessor for the set of entries in the Map.

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

Returns:

Set of entries

equals

public boolean equals(Object o)

Method to check the equality of this map, and another.

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class AbstractMap<K,V>

Parameters:

o - The map to compare against.

Returns:

Whether they are equal.

forEach

public void forEach(BiConsumer<? super K, ? super V> action)

Specified by:

forEach in interface Map<K,V>

get

public V get(Object key)

Accessor for the value stored against a key.

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

Parameters:

key - The key

Returns:

The value.

hashCode

public int hashCode()

Method to generate a hashcode for this Map.

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class AbstractMap<K,V>

Returns:

The hashcode.

isEmpty

public boolean isEmpty()

Method to return if the Map is empty.

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class AbstractMap<K,V>

Returns:

Whether it is empty.

keySet

public Set<K> keySet()

Accessor for the set of keys in the Map.

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class AbstractMap<K,V>

Returns:

Set of keys.

size

public int size()

Method to return the size of the Map.

Specified by:

size in interface Map<K,V>

Overrides:

size in class AbstractMap<K,V>

Returns:

The size

values

public Collection<V> values()

Accessor for the set of values in the Map.

Specified by:

values in interface Map<K,V>

Overrides:

values in class AbstractMap<K,V>

Returns:

Set of values.

clear

public void clear()

Method to clear the Map.

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

put

public V put(K key,
 V value)

Method to add a value to the Map.

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

Parameters:

key - The key for the value.

value - The value

Returns:

The previous value against this key (if any).

putAll

public void putAll(Map m)

Method to add a Map of values to this map.

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class AbstractMap<K,V>

Parameters:

m - The Map to add

remove

public V remove(Object key)

Method to remove a value from the Map.

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

Parameters:

key - The key for the value.

Returns:

The value removed.

writeReplace

protected Object writeReplace()
                       throws ObjectStreamException

The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream. The ObjectOutputStream checks whether the class defines the writeReplace method. If the method is defined, the writeReplace method is called to allow the object to designate its replacement in the stream. The object returned should be either of the same type as the object passed in or an object that when read and resolved will result in an object of a type that is compatible with all references to the object.

Returns:

the replaced object

Throws:

ObjectStreamException - if an error occurs