org.datanucleus.store.types.wrappers

Class HashMap

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap

org.datanucleus.store.types.wrappers.HashMap

All Implemented Interfaces:

Serializable, Cloneable, Map, SCO<HashMap>, SCOContainer<HashMap>, SCOMap<HashMap>

Direct Known Subclasses:

HashMap

public class HashMap
extends HashMap
implements SCOMap<HashMap>

A mutable second-class HashMap 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 java.util.AbstractMap

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

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

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field and Description
protected HashMap	delegate The internal "delegate".
protected AbstractMemberMetaData	ownerMmd
protected ObjectProvider	ownerOP

Constructor Summary

Constructors

Constructor and Description
HashMap(ObjectProvider ownerOP, AbstractMemberMetaData mmd) Constructor

Method Summary

Modifier and Type	Method and Description
void	attachCopy(HashMap value) Method to return an attached copy of the passed (detached) value.
void	clear() Method to clear the HashMap.
Object	clone() Creates and returns a copy of this object.
boolean	containsKey(Object key) Method to return if the map contains this key
boolean	containsValue(Object value) Method to return if the map contains this value.
HashMap	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.
Object	get(Object key) Accessor for the value stored against a key.
String	getFieldName() Accessor for the field name that this HashMap relates to.
Object	getOwner() Accessor for the owner that this HashMap relates to.
HashMap	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(HashMap m) Method to initialise the SCO for use with the provided initial value.
void	initialise(HashMap 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	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
Object	put(Object key, Object value) Method to add a value against a key to the HashMap.
void	putAll(Map m) Method to add the specified Map's values under their keys here.
Object	remove(Object key) Method to remove the value for a key from the HashMap.
void	setValue(HashMap 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 details.
void	updateEmbeddedKey(Object key, int fieldNumber, Object newValue, boolean makeDirty) Method to update an embedded key in this map.
void	updateEmbeddedValue(Object value, int fieldNumber, Object newValue, boolean makeDirty) Method to update an embedded value in this map.
Collection	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 java.util.HashMap

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

Methods inherited from class java.util.AbstractMap

toString

Methods inherited from class java.lang.Object

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

Field Detail

ownerOP

protected transient ObjectProvider ownerOP

ownerMmd

protected transient AbstractMemberMetaData ownerMmd

delegate

protected HashMap delegate

The internal "delegate".

Constructor Detail

HashMap

public HashMap(ObjectProvider ownerOP,
               AbstractMemberMetaData mmd)

Constructor

Parameters:

ownerOP - the owner ObjectProvider

mmd - Metadata for the member

Method Detail

initialise

public void initialise(HashMap 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<HashMap>

Parameters:

newValue - New value (to wrap)

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

initialise

public void initialise(HashMap 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<HashMap>

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<HashMap>

getValue

public HashMap getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO<HashMap>

Returns:

The unwrapped value

setValue

public void setValue(HashMap 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<HashMap>

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<HashMap>

isLoaded

public boolean isLoaded()

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

Specified by:

isLoaded in interface SCOContainer<HashMap>

Returns:

Whether it is loaded

updateEmbeddedKey

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

Method to update an embedded key in this map.

Specified by:

updateEmbeddedKey in interface SCOMap<HashMap>

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(Object value,
                                int fieldNumber,
                                Object newValue,
                                boolean makeDirty)

Method to update an embedded value in this map.

Specified by:

updateEmbeddedValue in interface SCOMap<HashMap>

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 that this HashMap relates to.

Specified by:

getFieldName in interface SCO<HashMap>

Returns:

The field name

getOwner

public Object getOwner()

Accessor for the owner that this HashMap relates to.

Specified by:

getOwner in interface SCO<HashMap>

Returns:

The owner

unsetOwner

public void unsetOwner()

Method to unset the owner and field details.

Specified by:

unsetOwner in interface SCO<HashMap>

makeDirty

public void makeDirty()

Utility to mark the object as dirty

detachCopy

public HashMap 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<HashMap>

Parameters:

state - State for detachment process

Returns:

The detached container

attachCopy

public void attachCopy(HashMap 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<HashMap>

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<HashMap>

Overrides:

clone in class HashMap

Returns:

The cloned object

containsKey

public boolean containsKey(Object key)

Method to return if the map contains this key

Specified by:

containsKey in interface Map

Overrides:

containsKey in class HashMap

Parameters:

key - The key

Returns:

Whether it is contained

containsValue

public boolean containsValue(Object value)

Method to return if the map contains this value.

Specified by:

containsValue in interface Map

Overrides:

containsValue in class HashMap

Parameters:

value - The value

Returns:

Whether it is contained

entrySet

public Set entrySet()

Accessor for the set of entries in the Map.

Specified by:

entrySet in interface Map

Overrides:

entrySet in class HashMap

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

Overrides:

equals in class AbstractMap

Parameters:

o - The map to compare against.

Returns:

Whether they are equal.

get

public Object get(Object key)

Accessor for the value stored against a key.

Specified by:

get in interface Map

Overrides:

get in class HashMap

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

Overrides:

hashCode in class AbstractMap

Returns:

The hashcode.

isEmpty

public boolean isEmpty()

Method to return if the Map is empty.

Specified by:

isEmpty in interface Map

Overrides:

isEmpty in class HashMap

Returns:

Whether it is empty.

keySet

public Set keySet()

Accessor for the set of keys in the Map.

Specified by:

keySet in interface Map

Overrides:

keySet in class HashMap

Returns:

Set of keys.

size

public int size()

Method to return the size of the Map.

Specified by:

size in interface Map

Overrides:

size in class HashMap

Returns:

The size

values

public Collection values()

Accessor for the set of values in the Map.

Specified by:

values in interface Map

Overrides:

values in class HashMap

Returns:

Set of values.

clear

public void clear()

Method to clear the HashMap.

Specified by:

clear in interface Map

Overrides:

clear in class HashMap

put

public Object put(Object key,
                  Object value)

Method to add a value against a key to the HashMap.

Specified by:

put in interface Map

Overrides:

put in class HashMap

Parameters:

key - The key

value - The value

Returns:

The previous value for the specified key.

putAll

public void putAll(Map m)

Method to add the specified Map's values under their keys here.

Specified by:

putAll in interface Map

Overrides:

putAll in class HashMap

Parameters:

m - The map

remove

public Object remove(Object key)

Method to remove the value for a key from the HashMap.

Specified by:

remove in interface Map

Overrides:

remove in class HashMap

Parameters:

key - The key to remove

Returns:

The value that was removed from this key.

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