org.datanucleus.store.types.wrappers

Class HashSet<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractSet<E>

java.util.HashSet<E>

org.datanucleus.store.types.wrappers.HashSet<E>

All Implemented Interfaces:

Serializable, Cloneable, Iterable<E>, Collection<E>, Set<E>, SCO<HashSet<E>>, SCOCollection<HashSet<E>,E>, SCOContainer<HashSet<E>>

Direct Known Subclasses:

HashSet

public class HashSet<E>
extends HashSet<E>
implements SCOCollection<HashSet<E>,E>

A mutable second-class HashSet 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

Field Summary

Fields

Modifier and Type	Field and Description
protected HashSet<E>	delegate The internal "delegate".
protected AbstractMemberMetaData	ownerMmd
protected ObjectProvider	ownerOP

Constructor Summary

Constructors

Constructor and Description
HashSet(ObjectProvider ownerOP, AbstractMemberMetaData mmd) Constructor, using the ObjectProvider of the "owner" and the field name.

Method Summary

Modifier and Type	Method and Description
boolean	add(E element) Method to add an element to the set.
boolean	addAll(Collection c) Method to add a collection to the set.
void	attachCopy(HashSet value) Method to return an attached copy of the passed (detached) value.
void	clear() Method to clear the HashSet
Object	clone() Creates and returns a copy of this object.
boolean	contains(Object element) Accessor for whether an element is contained in this set.
boolean	containsAll(Collection c) Accessor for whether a collection is contained in this set.
HashSet	detachCopy(FetchPlanState state) Method to return a detached copy of the container.
boolean	equals(Object o)
String	getFieldName() Accessor for the field name.
Object	getOwner() Accessor for the owner object.
HashSet<E>	getValue() Accessor for the unwrapped value that we are wrapping.
int	hashCode()
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(HashSet c) Method to initialise the SCO for use with the provided initial value.
void	initialise(HashSet<E> 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() Accessor for whether the HashSet is empty.
boolean	isLoaded() Method to return if the SCO has its contents loaded.
Iterator<E>	iterator() Accessor for an iterator for the Set.
void	load() Method to effect the load of the data in the SCO.
void	makeDirty() Utility to mark the object as dirty
boolean	remove(Object element) Method to remove an element from the set
boolean	remove(Object element, boolean allowCascadeDelete) Method to remove an element from the set
boolean	removeAll(Collection elements) Method to remove all elements from the collection from the set.
boolean	retainAll(Collection c) Method to retain a Collection of elements (and remove all others).
void	setValue(HashSet<E> value) Method to change the delegate value this wraps (to save recreating the wrapper).
int	size() Accessor for the size of the HashSet.
Object[]	toArray() Method to return the list as an array.
Object[]	toArray(Object[] a) Method to return the list as an array.
void	unsetOwner() Method to unset the owner and field information.
void	updateEmbeddedElement(E element, int fieldNumber, Object value, boolean makeDirty) Method to update an embedded element in this collection.
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.HashSet

spliterator

Methods inherited from class java.util.AbstractCollection

toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

ownerOP

protected transient ObjectProvider ownerOP

ownerMmd

protected transient AbstractMemberMetaData ownerMmd

delegate

protected HashSet<E> delegate

The internal "delegate".

Constructor Detail

HashSet

public HashSet(ObjectProvider ownerOP,
               AbstractMemberMetaData mmd)

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

Parameters:

ownerOP - The owner ObjectProvider

mmd - Metadata for the member

Method Detail

initialise

public void initialise(HashSet<E> 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<HashSet<E>>

Parameters:

newValue - New value (to wrap)

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

initialise

public void initialise(HashSet c)

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<HashSet<E>>

Parameters:

c - 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<HashSet<E>>

getValue

public HashSet<E> getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO<HashSet<E>>

Returns:

The unwrapped value

setValue

public void setValue(HashSet<E> 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<HashSet<E>>

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<HashSet<E>>

isLoaded

public boolean isLoaded()

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

Specified by:

isLoaded in interface SCOContainer<HashSet<E>>

Returns:

Whether it is loaded

updateEmbeddedElement

public void updateEmbeddedElement(E element,
                                  int fieldNumber,
                                  Object value,
                                  boolean makeDirty)

Method to update an embedded element in this collection.

Specified by:

updateEmbeddedElement in interface SCOCollection<HashSet<E>,E>

Parameters:

element - The element

fieldNumber - Number of field in the element

value - 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<HashSet<E>>

Returns:

The field name

getOwner

public Object getOwner()

Accessor for the owner object.

Specified by:

getOwner in interface SCO<HashSet<E>>

Returns:

The owner object

unsetOwner

public void unsetOwner()

Method to unset the owner and field information.

Specified by:

unsetOwner in interface SCO<HashSet<E>>

makeDirty

public void makeDirty()

Utility to mark the object as dirty

detachCopy

public HashSet detachCopy(FetchPlanState state)

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

Specified by:

detachCopy in interface SCO<HashSet<E>>

Parameters:

state - State for detachment process

Returns:

The detached container

attachCopy

public void attachCopy(HashSet value)

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

Specified by:

attachCopy in interface SCO<HashSet<E>>

Parameters:

value - The new (collection) value

clone

public Object clone()

Creates and returns a copy of this object.

Specified by:

clone in interface SCO<HashSet<E>>

Overrides:

clone in class HashSet<E>

Returns:

The cloned object

contains

public boolean contains(Object element)

Accessor for whether an element is contained in this set.

Specified by:

contains in interface Collection<E>

Specified by:

contains in interface Set<E>

Overrides:

contains in class HashSet<E>

Parameters:

element - The element

Returns:

Whether it is contained.

containsAll

public boolean containsAll(Collection c)

Accessor for whether a collection is contained in this set.

Specified by:

containsAll in interface Collection<E>

Specified by:

containsAll in interface Set<E>

Overrides:

containsAll in class AbstractCollection<E>

Parameters:

c - The collection

Returns:

Whether it is contained.

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection<E>

Specified by:

equals in interface Set<E>

Overrides:

equals in class AbstractSet<E>

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<E>

Specified by:

hashCode in interface Set<E>

Overrides:

hashCode in class AbstractSet<E>

isEmpty

public boolean isEmpty()

Accessor for whether the HashSet is empty.

Specified by:

isEmpty in interface Collection<E>

Specified by:

isEmpty in interface Set<E>

Overrides:

isEmpty in class HashSet<E>

Returns:

Whether it is empty.

iterator

public Iterator<E> iterator()

Accessor for an iterator for the Set.

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Set<E>

Overrides:

iterator in class HashSet<E>

Returns:

The iterator

size

public int size()

Accessor for the size of the HashSet.

Specified by:

size in interface Collection<E>

Specified by:

size in interface Set<E>

Overrides:

size in class HashSet<E>

Returns:

The size.

toArray

public Object[] toArray()

Method to return the list as an array.

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface Set<E>

Overrides:

toArray in class AbstractCollection<E>

Returns:

The array

toArray

public Object[] toArray(Object[] a)

Method to return the list as an array.

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface Set<E>

Overrides:

toArray in class AbstractCollection<E>

Parameters:

a - The runtime types of the array being defined by this param

Returns:

The array

add

public boolean add(E element)

Method to add an element to the set.

Specified by:

add in interface Collection<E>

Specified by:

add in interface Set<E>

Overrides:

add in class HashSet<E>

Parameters:

element - The new element

Returns:

Whether it was added ok.

addAll

public boolean addAll(Collection c)

Method to add a collection to the set.

Specified by:

addAll in interface Collection<E>

Specified by:

addAll in interface Set<E>

Overrides:

addAll in class AbstractCollection<E>

Parameters:

c - The collection

Returns:

Whether it was added ok.

clear

public void clear()

Method to clear the HashSet

Specified by:

clear in interface Collection<E>

Specified by:

clear in interface Set<E>

Overrides:

clear in class HashSet<E>

remove

public boolean remove(Object element)

Method to remove an element from the set

Specified by:

remove in interface Collection<E>

Specified by:

remove in interface Set<E>

Overrides:

remove in class HashSet<E>

Parameters:

element - The Element to remove

Returns:

Whether it was removed successfully.

remove

public boolean remove(Object element,
                      boolean allowCascadeDelete)

Method to remove an element from the set

Specified by:

remove in interface SCOCollection<HashSet<E>,E>

Parameters:

element - The Element to remove

allowCascadeDelete - Whether to allow cascade delete

Returns:

Whether it was removed successfully.

removeAll

public boolean removeAll(Collection elements)

Method to remove all elements from the collection from the set.

Specified by:

removeAll in interface Collection<E>

Specified by:

removeAll in interface Set<E>

Overrides:

removeAll in class AbstractSet<E>

Parameters:

elements - The collection of elements to remove

Returns:

Whether it was removed ok.

retainAll

public boolean retainAll(Collection c)

Method to retain a Collection of elements (and remove all others).

Specified by:

retainAll in interface Collection<E>

Specified by:

retainAll in interface Set<E>

Overrides:

retainAll in class AbstractCollection<E>

Parameters:

c - The collection to retain

Returns:

Whether they were retained successfully.

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