org.jpox.sco
Class List

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractList
          org.jpox.sco.List

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Iterable, java.util.Collection, java.util.List, SCO, SCOCollection, SCOLazyLoading, SCOList, Queryable

public class List
extends java.util.AbstractList
implements SCOList, SCOLazyLoading, java.lang.Cloneable, Queryable, java.io.Serializable

A mutable second-class List object, representing a field in a class, and containing elements of a particular type. Uses a "delegate" as a local store for the List. Uses a "backing store" (ListStore) to represent the datastore. The "delegate" is updated with the "backing store" information at necessary intervals.

Modes of Operation

The user can operate the collection in 2 modes. The cached mode will use an internal cache of the elements (in the "delegate") reading them at the first opportunity and then using the cache thereafter. The non-cached mode will just go direct to the "backing store" each call.

Mutators

When the backing store is present any updates are passed direct to the datastore as well as to the "delegate". If the "backing store" isn't present the changes are made to the "delegate" only.

Accessors

When any accessor method is invoked, it typically checks whether the collection has been loaded from its backing store and does this as necessary. Some methods (size(), contains()) just check if everything is loaded and use the delegate if possible, otherwise going direct to the datastore.

Version:

$Revision: 1.52 $

See Also:

Serialized Form

Field Summary

protected boolean	isCacheLoaded Status flag whether the collection is loaded into the cache.
protected boolean	useCache Whether to use "delegate" caching.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

List(StateManager ownerSM, java.lang.String fieldName)
Constructor, using the StateManager of the "owner" and the field name.

Method Summary

void	add(int index, java.lang.Object element) Method to add an element to the List at a position.
boolean	add(java.lang.Object element) Method to add an element to the List
boolean	addAll(java.util.Collection elements) Method to add a Collection to the ArrayList.
boolean	addAll(int index, java.util.Collection elements) Method to add a collection of elements.
void	attachCopy(java.lang.Object value) Method to return an attached copy of the passed (detached) value.
void	clear() Method to clear the List
java.lang.Object	clone() Creates and returns a copy of this object.
boolean	contains(java.lang.Object element) Accessor for whether an element is contained in the List.
boolean	containsAll(java.util.Collection c) Accessor for whether a collection of elements are contained here.
void	detach(FetchPlanState state) Method to detach the PersistenceCapable elements of this container.
java.lang.Object	detachCopy(FetchPlanState state) Method to return a detached copy of the container.
boolean	equals(java.lang.Object o) Equality operator.
java.lang.Object	get(int index) Method to retrieve an element no.
java.lang.Class	getElementType() Accessor for the element type.
java.lang.String	getFieldName() Accessor for the field name.
java.lang.Object	getOwner() Accessor for the owner object.
int	hashCode() Hashcode operator.
int	indexOf(java.lang.Object element) Method to the position of an element.
boolean	isEmpty() Accessor for whether the List is empty.
java.util.Iterator	iterator() Accessor for an iterator for the List
int	lastIndexOf(java.lang.Object element) Method to retrieve the last position of the element.
java.util.ListIterator	listIterator() Method to retrieve a List iterator for the list.
java.util.ListIterator	listIterator(int index) Method to retrieve a List iterator for the list from the index.
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.
void	makeDirty() Utility to mark the object as dirty
void	makeTransient(FetchPlanState state) Method to make transient all elements of this container.
QueryExpression	newQueryStatement() Method to generate a QueryStatement for the SCO.
QueryExpression	newQueryStatement(java.lang.Class candidate_class) Method to return a QueryStatement, using the specified candidate class.
Query.ResultObjectFactory	newResultObjectFactory(QueryExpression stmt, boolean ignoreCache, java.lang.Class resultClass, boolean useFetchPlan) Method to return a ResultObjectFactory for the SCO.
java.lang.Object	remove(int index) Method to remove an element from the ArrayList.
boolean	remove(java.lang.Object element) Method to remove an element from the List
boolean	removeAll(java.util.Collection elements) Method to remove a collection of elements from the List.
boolean	retainAll(java.util.Collection c) Method to retain a Collection of elements (and remove all others).
void	runReachability(java.util.Set reachables) Method to run reachability on this SCO.
java.lang.Object	set(int index, java.lang.Object element) Method to set the element at a position in the ArrayList.
java.lang.Object	set(int index, java.lang.Object element, boolean allowDependentField) JPOX wrapper addition that allows turning off of the dependent-field checks when doing the position setting.
void	setValueFrom(java.lang.Object o, boolean forUpdate) Mutator for setting using an object.
int	size() Accessor for the size of the List
java.util.List	subList(int from, int to) Accessor for the subList of elements between from and to of the List
java.lang.Object[]	toArray() Method to return the List as an array.
java.lang.Object[]	toArray(java.lang.Object[] a) Method to return the List as an array.
void	unsetOwner() Method to unset the owner and field information.
void	updateEmbeddedElement(java.lang.Object element, int fieldNumber, java.lang.Object value) Method to update an embedded element in this collection.
protected java.lang.Object	writeReplace() The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream.

Methods inherited from class java.util.AbstractList

removeRange

Methods inherited from class java.util.AbstractCollection

toString

Methods inherited from class java.lang.Object

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

Field Detail

useCache

protected boolean useCache

Whether to use "delegate" caching.

isCacheLoaded

protected boolean isCacheLoaded

Status flag whether the collection is loaded into the cache.

Constructor Detail

List

public List(StateManager ownerSM,
            java.lang.String fieldName)

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

Parameters:

ownerSM - The owner StateManager

fieldName - The name of the field of the SCO.

Method Detail

getElementType

public java.lang.Class getElementType()

Accessor for the element type.

Specified by:

getElementType in interface SCOCollection

Returns:

the element type contained in the collection

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 SCOLazyLoading

updateEmbeddedElement

public void updateEmbeddedElement(java.lang.Object element,
                                  int fieldNumber,
                                  java.lang.Object value)

Method to update an embedded element in this collection.

Specified by:

updateEmbeddedElement in interface SCOCollection

Parameters:

element - The element

fieldNumber - Number of field in the element

value - New value for this field

setValueFrom

public void setValueFrom(java.lang.Object o,
                         boolean forUpdate)

Mutator for setting using an object.

Specified by:

setValueFrom in interface SCO

Parameters:

o - The object to set from

forUpdate - Whether to update the datastore with this value

getFieldName

public java.lang.String getFieldName()

Accessor for the field name.

Specified by:

getFieldName in interface SCO

Returns:

The field name

getOwner

public java.lang.Object getOwner()

Accessor for the owner object.

Specified by:

getOwner in interface SCO

Returns:

The owner object

unsetOwner

public void unsetOwner()

Method to unset the owner and field information.

Specified by:

unsetOwner in interface SCO

makeDirty

public void makeDirty()

Utility to mark the object as dirty

runReachability

public void runReachability(java.util.Set reachables)

Method to run reachability on this SCO.

Specified by:

runReachability in interface SCO

Parameters:

reachables - List of StateManagers reachable so far

makeTransient

public void makeTransient(FetchPlanState state)

Method to make transient all elements of this container. All elements that are PersistenceCapable will be made transient.

Specified by:

makeTransient in interface SCO

Parameters:

state - State for the fetchplan process

detach

public void detach(FetchPlanState state)

Method to detach the PersistenceCapable elements of this container.

Specified by:

detach in interface SCO

Parameters:

state - State for the detachment process

detachCopy

public java.lang.Object 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

Parameters:

state - State for detachment process

Returns:

The detached container

attachCopy

public void attachCopy(java.lang.Object 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

Parameters:

value - The new (collection) value

newQueryStatement

public QueryExpression newQueryStatement()

Method to generate a QueryStatement for the SCO.

Specified by:

newQueryStatement in interface Queryable

Returns:

The QueryStatement

newQueryStatement

public QueryExpression newQueryStatement(java.lang.Class candidate_class)

Method to return a QueryStatement, using the specified candidate class.

Specified by:

newQueryStatement in interface Queryable

Parameters:

candidate_class - The candidate class

Returns:

The QueryStatement

See Also:

Queryable.newQueryStatement()

newResultObjectFactory

public Query.ResultObjectFactory newResultObjectFactory(QueryExpression stmt,
                                                        boolean ignoreCache,
                                                        java.lang.Class resultClass,
                                                        boolean useFetchPlan)

Method to return a ResultObjectFactory for the SCO.

Specified by:

newResultObjectFactory in interface Queryable

Parameters:

stmt - The QueryStatement

ignoreCache - Whether to ignore the cache

resultClass - Whether to create objects of a particular class

useFetchPlan - whether to use the fetch plan to retrieve fields in the same query

Returns:

The ResultObjectFactory

clone

public java.lang.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 java.lang.Object

Returns:

The cloned object

contains

public boolean contains(java.lang.Object element)

Accessor for whether an element is contained in the List.

Specified by:

contains in interface java.util.Collection

Specified by:

contains in interface java.util.List

Overrides:

contains in class java.util.AbstractCollection

Parameters:

element - The element

Returns:

Whether the element is contained here

containsAll

public boolean containsAll(java.util.Collection c)

Accessor for whether a collection of elements are contained here.

Specified by:

containsAll in interface java.util.Collection

Specified by:

containsAll in interface java.util.List

Overrides:

containsAll in class java.util.AbstractCollection

Parameters:

c - The collection of elements.

Returns:

Whether they are contained.

equals

public boolean equals(java.lang.Object o)

Equality operator.

Specified by:

equals in interface java.util.Collection

Specified by:

equals in interface java.util.List

Overrides:

equals in class java.util.AbstractList

Parameters:

o - The object to compare against.

Returns:

Whether this object is the same.

get

public java.lang.Object get(int index)

Method to retrieve an element no.

Specified by:

get in interface java.util.List

Specified by:

get in class java.util.AbstractList

Parameters:

index - The item to retrieve

Returns:

The element at that position.

hashCode

public int hashCode()

Hashcode operator.

Specified by:

hashCode in interface java.util.Collection

Specified by:

hashCode in interface java.util.List

Overrides:

hashCode in class java.util.AbstractList

Returns:

The Hash code.

indexOf

public int indexOf(java.lang.Object element)

Method to the position of an element.

Specified by:

indexOf in interface java.util.List

Overrides:

indexOf in class java.util.AbstractList

Parameters:

element - The element.

Returns:

The position.

isEmpty

public boolean isEmpty()

Accessor for whether the List is empty.

Specified by:

isEmpty in interface java.util.Collection

Specified by:

isEmpty in interface java.util.List

Specified by:

isEmpty in interface Queryable

Overrides:

isEmpty in class java.util.AbstractCollection

Returns:

Whether it is empty.

lastIndexOf

public int lastIndexOf(java.lang.Object element)

Method to retrieve the last position of the element.

Specified by:

lastIndexOf in interface java.util.List

Overrides:

lastIndexOf in class java.util.AbstractList

Parameters:

element - The element

Returns:

The last position of this element in the List.

iterator

public java.util.Iterator iterator()

Accessor for an iterator for the List

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Specified by:

iterator in interface java.util.List

Overrides:

iterator in class java.util.AbstractList

Returns:

The iterator

listIterator

public java.util.ListIterator listIterator()

Method to retrieve a List iterator for the list.

Specified by:

listIterator in interface java.util.List

Overrides:

listIterator in class java.util.AbstractList

Returns:

The iterator

listIterator

public java.util.ListIterator listIterator(int index)

Method to retrieve a List iterator for the list from the index.

Specified by:

listIterator in interface java.util.List

Overrides:

listIterator in class java.util.AbstractList

Parameters:

index - The start point

Returns:

The iterator

size

public int size()

Accessor for the size of the List

Specified by:

size in interface java.util.Collection

Specified by:

size in interface java.util.List

Specified by:

size in class java.util.AbstractCollection

Returns:

The size

subList

public java.util.List subList(int from,
                              int to)

Accessor for the subList of elements between from and to of the List

Specified by:

subList in interface java.util.List

Overrides:

subList in class java.util.AbstractList

Parameters:

from - Start index (inclusive)

to - End index (exclusive)

Returns:

The subList

toArray

public java.lang.Object[] toArray()

Method to return the List as an array.

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.List

Overrides:

toArray in class java.util.AbstractCollection

Returns:

The array

toArray

public java.lang.Object[] toArray(java.lang.Object[] a)

Method to return the List as an array.

Specified by:

toArray in interface java.util.Collection

Specified by:

toArray in interface java.util.List

Overrides:

toArray in class java.util.AbstractCollection

Parameters:

a - The array to copy to

Returns:

The array

add

public boolean add(java.lang.Object element)

Method to add an element to the List

Specified by:

add in interface java.util.Collection

Specified by:

add in interface java.util.List

Overrides:

add in class java.util.AbstractList

Parameters:

element - The element to add

Returns:

Whether it was added successfully.

add

public void add(int index,
                java.lang.Object element)

Method to add an element to the List at a position.

Specified by:

add in interface java.util.List

Overrides:

add in class java.util.AbstractList

Parameters:

element - The element to add

index - The position

addAll

public boolean addAll(java.util.Collection elements)

Method to add a Collection to the ArrayList.

Specified by:

addAll in interface java.util.Collection

Specified by:

addAll in interface java.util.List

Overrides:

addAll in class java.util.AbstractCollection

Parameters:

elements - The collection

Returns:

Whether it was added ok.

addAll

public boolean addAll(int index,
                      java.util.Collection elements)

Method to add a collection of elements.

Specified by:

addAll in interface java.util.List

Overrides:

addAll in class java.util.AbstractList

Parameters:

elements - The collection of elements to add.

index - The position to add them

Returns:

Whether they were added successfully.

clear

public void clear()

Method to clear the List

Specified by:

clear in interface java.util.Collection

Specified by:

clear in interface java.util.List

Overrides:

clear in class java.util.AbstractList

remove

public boolean remove(java.lang.Object element)

Method to remove an element from the List

Specified by:

remove in interface java.util.Collection

Specified by:

remove in interface java.util.List

Overrides:

remove in class java.util.AbstractCollection

Parameters:

element - The Element to remove

Returns:

Whether it was removed successfully.

remove

public java.lang.Object remove(int index)

Method to remove an element from the ArrayList.

Specified by:

remove in interface java.util.List

Overrides:

remove in class java.util.AbstractList

Parameters:

index - The element position.

Returns:

The object that was removed

removeAll

public boolean removeAll(java.util.Collection elements)

Method to remove a collection of elements from the List.

Specified by:

removeAll in interface java.util.Collection

Specified by:

removeAll in interface java.util.List

Overrides:

removeAll in class java.util.AbstractCollection

Parameters:

elements - Collection of elements to remove

Returns:

Whether it was successful.

retainAll

public boolean retainAll(java.util.Collection c)

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

Specified by:

retainAll in interface java.util.Collection

Specified by:

retainAll in interface java.util.List

Overrides:

retainAll in class java.util.AbstractCollection

Parameters:

c - The collection to retain

Returns:

Whether they were retained successfully.

set

public java.lang.Object set(int index,
                            java.lang.Object element,
                            boolean allowDependentField)

JPOX wrapper addition that allows turning off of the dependent-field checks when doing the position setting. This means that we can prevent the deletion of the object that was previously in that position. This particular feature is used when attaching a list field and where some elements have changed positions.

Specified by:

set in interface SCOList

Parameters:

index - The position

element - The new element

allowDependentField - Whether to allow dependent-field deletes

Returns:

The element previously at that position

set

public java.lang.Object set(int index,
                            java.lang.Object element)

Method to set the element at a position in the ArrayList.

Specified by:

set in interface java.util.List

Overrides:

set in class java.util.AbstractList

Parameters:

index - The position

element - The new element

Returns:

The element previously at that position

writeReplace

protected java.lang.Object writeReplace()
                                 throws java.io.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:

java.io.ObjectStreamException

loadFromStore

protected void loadFromStore()

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