org.datanucleus.store.types.wrappers.backed

Class LinkedHashMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

java.util.LinkedHashMap<K,V>

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

org.datanucleus.store.types.wrappers.backed.LinkedHashMap<K,V>

All Implemented Interfaces:

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

public class LinkedHashMap<K,V>
extends LinkedHashMap<K,V>
implements BackedSCO

A mutable second-class LinkedHashMap object. Backed by a MapStore object.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

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

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	allowNulls
protected MapStore<K,V>	backingStore
protected boolean	isCacheLoaded
protected boolean	useCache

Fields inherited from class org.datanucleus.store.types.wrappers.LinkedHashMap

delegate, ownerMmd, ownerOP

Constructor Summary

Constructors

Constructor and Description
LinkedHashMap(ObjectProvider op, AbstractMemberMetaData mmd) Constructor

Method Summary

Modifier and Type	Method and Description
void	clear() Method to clear the LinkedHashMap.
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.
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.
V	get(Object key) Accessor for the value stored against a key.
Store	getBackingStore()
LinkedHashMap	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.
void	initialise(LinkedHashMap m) Method to initialise the SCO from an existing value.
void	initialise(LinkedHashMap 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.
protected void	loadFromStore() Method to load all elements from the "backing store" where appropriate.
V	put(K key, V value) Method to add a value against a key to the LinkedHashMap.
void	putAll(Map m) Method to add the specified Map's values under their keys here.
V	remove(Object key) Method to remove the value for a key from the LinkedHashMap.
int	size() Method to return the size of the Map.
void	unsetOwner() Method to unset the owner and field details.
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	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 org.datanucleus.store.types.wrappers.LinkedHashMap

attachCopy, detachCopy, getFieldName, getOwner, makeDirty, setValue

Methods inherited from class java.util.LinkedHashMap

forEach, getOrDefault, removeEldestEntry, replaceAll

Methods inherited from class java.util.HashMap

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

Methods inherited from class java.util.AbstractMap

toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Field Detail

allowNulls

protected transient boolean allowNulls

backingStore

protected transient MapStore<K,V> backingStore

useCache

protected transient boolean useCache

isCacheLoaded

protected transient boolean isCacheLoaded

Constructor Detail

LinkedHashMap

public LinkedHashMap(ObjectProvider op,
                     AbstractMemberMetaData mmd)

Constructor

Parameters:

op - the owner of this Map

mmd - Metadata for the member

Method Detail

initialise

public void initialise(LinkedHashMap 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<LinkedHashMap<K,V>>

Overrides:

initialise in class LinkedHashMap<K,V>

Parameters:

newValue - New value (to wrap)

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

initialise

public void initialise(LinkedHashMap m)

Method to initialise the SCO from an existing value.

Specified by:

initialise in interface SCO<LinkedHashMap<K,V>>

Overrides:

initialise in class LinkedHashMap<K,V>

Parameters:

m - Object to set value using.

initialise

public void initialise()

Method to initialise the SCO for use.

Specified by:

initialise in interface SCO<LinkedHashMap<K,V>>

Overrides:

initialise in class LinkedHashMap<K,V>

getValue

public LinkedHashMap getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO<LinkedHashMap<K,V>>

Overrides:

getValue in class LinkedHashMap<K,V>

Returns:

The unwrapped 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<LinkedHashMap<K,V>>

Overrides:

load in class LinkedHashMap<K,V>

isLoaded

public boolean isLoaded()

Method to return if the SCO has its contents loaded. If the SCO doesn't support lazy loading will just return true.

Specified by:

isLoaded in interface SCOContainer<LinkedHashMap<K,V>>

Overrides:

isLoaded in class LinkedHashMap<K,V>

Returns:

Whether it is loaded

loadFromStore

protected void loadFromStore()

Method to load all elements from the "backing store" where appropriate.

getBackingStore

public Store getBackingStore()

Specified by:

getBackingStore in interface BackedSCO

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<LinkedHashMap<K,V>,K,V>

Overrides:

updateEmbeddedKey in class LinkedHashMap<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<LinkedHashMap<K,V>,K,V>

Overrides:

updateEmbeddedValue in class LinkedHashMap<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.

unsetOwner

public void unsetOwner()

Method to unset the owner and field details.

Specified by:

unsetOwner in interface SCO<LinkedHashMap<K,V>>

Overrides:

unsetOwner in class LinkedHashMap<K,V>

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<LinkedHashMap<K,V>>

Overrides:

clone in class LinkedHashMap<K,V>

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<K,V>

Overrides:

containsKey in class LinkedHashMap<K,V>

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<K,V>

Overrides:

containsValue in class LinkedHashMap<K,V>

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<K,V>

Overrides:

entrySet in class LinkedHashMap<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 LinkedHashMap<K,V>

Parameters:

o - The map to compare against.

Returns:

Whether they are equal.

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 LinkedHashMap<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 LinkedHashMap<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 LinkedHashMap<K,V>

Returns:

Whether it is empty.

keySet

public Set keySet()

Accessor for the set of keys in the Map.

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class LinkedHashMap<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 LinkedHashMap<K,V>

Returns:

The size

values

public Collection values()

Accessor for the set of values in the Map.

Specified by:

values in interface Map<K,V>

Overrides:

values in class LinkedHashMap<K,V>

Returns:

Set of values.

clear

public void clear()

Method to clear the LinkedHashMap.

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class LinkedHashMap<K,V>

put

public V put(K key,
             V value)

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

Specified by:

put in interface Map<K,V>

Overrides:

put in class LinkedHashMap<K,V>

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<K,V>

Overrides:

putAll in class LinkedHashMap<K,V>

Parameters:

m - The map

remove

public V remove(Object key)

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

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class LinkedHashMap<K,V>

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.

Overrides:

writeReplace in class LinkedHashMap<K,V>

Returns:

the replaced object

Throws:

ObjectStreamException - if an error occurs