org.datanucleus.store.types.sco.backed
Class LinkedHashMap

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<K,V>
          java.util.LinkedHashMap
              org.datanucleus.store.types.sco.simple.LinkedHashMap
                  org.datanucleus.store.types.sco.backed.LinkedHashMap

All Implemented Interfaces:

Serializable, Cloneable, Map, SCO, SCOContainer, SCOMap

public class LinkedHashMap
extends LinkedHashMap

A mutable second-class LinkedHashMap object. Backed by a MapStore object. Only available for JRE 1.4 or above.

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

protected boolean	allowNulls
protected MapStore	backingStore
protected boolean	isCacheLoaded
protected OperationQueue<MapStore>	operationQueue
protected boolean	queued
protected boolean	useCache

Fields inherited from class org.datanucleus.store.types.sco.simple.LinkedHashMap

delegate, fieldName, fieldNumber, LOCALISER, ownerSM

Constructor Summary

LinkedHashMap(ObjectProvider ownerSM, String fieldName)
Constructor

Method Summary

protected void	addQueuedOperation(QueuedOperation<? super MapStore> op) Convenience method to add a queued operation to the operations we perform at commit.
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.
void	flush() Method to flush the changes to the datastore when operating in queued mode.
Object	get(Object key) Accessor for the value stored against a key.
Object	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(Object o, boolean forInsert, boolean forUpdate) Method to initialise the SCO from an existing 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.
Object	put(Object key, Object 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.
Object	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(Object key, int fieldNumber, Object newValue) Method to update an embedded key in this map.
void	updateEmbeddedValue(Object value, int fieldNumber, Object newValue) 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.sco.simple.LinkedHashMap

attachCopy, detachCopy, getFieldName, getOwner, makeDirty

Methods inherited from class java.util.LinkedHashMap

removeEldestEntry

Methods inherited from class java.util.AbstractMap

toString

Methods inherited from class java.lang.Object

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

Field Detail

allowNulls

protected transient boolean allowNulls

backingStore

protected transient MapStore backingStore

useCache

protected transient boolean useCache

isCacheLoaded

protected transient boolean isCacheLoaded

queued

protected transient boolean queued

operationQueue

protected transient OperationQueue<MapStore> operationQueue

Constructor Detail

LinkedHashMap

public LinkedHashMap(ObjectProvider ownerSM,
                     String fieldName)

Constructor

Parameters:

ownerSM - the owner of this Map

fieldName - the declared field name

Method Detail

initialise

public void initialise(Object o,
                       boolean forInsert,
                       boolean forUpdate)

Method to initialise the SCO from an existing value.

Specified by:

initialise in interface SCO

Overrides:

initialise in class LinkedHashMap

Parameters:

o - Object to set value using.

forInsert - Whether the object needs inserting in the datastore with this value

forUpdate - Whether to update the datastore with this value

initialise

public void initialise()

Method to initialise the SCO for use.

Specified by:

initialise in interface SCO

Overrides:

initialise in class LinkedHashMap

getValue

public Object getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO

Overrides:

getValue in class LinkedHashMap

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

Overrides:

load in class LinkedHashMap

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

Overrides:

isLoaded in class LinkedHashMap

Returns:

Whether it is loaded

loadFromStore

protected void loadFromStore()

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

flush

public void flush()

Method to flush the changes to the datastore when operating in queued mode. Does nothing in "direct" mode.

Specified by:

flush in interface SCOContainer

Overrides:

flush in class LinkedHashMap

addQueuedOperation

protected void addQueuedOperation(QueuedOperation<? super MapStore> op)

Convenience method to add a queued operation to the operations we perform at commit.

Parameters:

op - The operation

updateEmbeddedKey

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

Method to update an embedded key in this map.

Specified by:

updateEmbeddedKey in interface SCOMap

Overrides:

updateEmbeddedKey in class LinkedHashMap

Parameters:

key - The key

fieldNumber - Number of field in the key

newValue - New value for this field

updateEmbeddedValue

public void updateEmbeddedValue(Object value,
                                int fieldNumber,
                                Object newValue)

Method to update an embedded value in this map.

Specified by:

updateEmbeddedValue in interface SCOMap

Overrides:

updateEmbeddedValue in class LinkedHashMap

Parameters:

value - The value

fieldNumber - Number of field in the value

newValue - New value for this field

unsetOwner

public void unsetOwner()

Method to unset the owner and field details.

Specified by:

unsetOwner in interface SCO

Overrides:

unsetOwner in class LinkedHashMap

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 PersistenceCapable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.

Specified by:

clone in interface SCO

Overrides:

clone in class LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

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 LinkedHashMap

Returns:

Set of values.

clear

public void clear()

Method to clear the LinkedHashMap.

Specified by:

clear in interface Map

Overrides:

clear in class LinkedHashMap

put

public Object put(Object key,
                  Object value)

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

Specified by:

put in interface Map

Overrides:

put in class LinkedHashMap

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 LinkedHashMap

Parameters:

m - The map

remove

public Object remove(Object key)

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

Specified by:

remove in interface Map

Overrides:

remove in class LinkedHashMap

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

Returns:

the replaced object

Throws:

ObjectStreamException