org.jpox.sco
Class Stack

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

All Implemented Interfaces:

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

public class Stack
extends java.util.Stack
implements SCOList, java.lang.Cloneable, Queryable

A mutable second-class Stack object. This class extends Stack, using that class to contain the current objects, and the backing ListStore to be the interface to the datastore. A "backing store" is not present for datastores that dont use DatastoreClass, or if the container is serialised or non-persistent.

Modes of Operation

The user can operate the list 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 container has been loaded from its "backing store" (where present) and does this as necessary. Some methods (size()) just check if everything is loaded and use the delegate if possible, otherwise going direct to the datastore.

Version:

$Revision: 1.93 $

See Also:

Serialized Form

Field Summary

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

Fields inherited from class java.util.Vector

capacityIncrement, elementCount, elementData

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Stack(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 a position in the Stack
boolean	add(java.lang.Object element) Method to add an element to the Stack
boolean	addAll(java.util.Collection elements) Method to add a Collection to the Stack
boolean	addAll(int index, java.util.Collection elements) Method to add a Collection to a position in the Stack
void	addElement(java.lang.Object element) Method to add an element to the Stack
protected void	addQueuedOperation(QueuedOperation op) Convenience method to add a queued operation to the operations we perform at commit.
void	attachCopy(java.lang.Object value) Method to return an attached copy of the passed (detached) value.
void	clear() Method to clear the Stack
java.lang.Object	clone() Clone operator to return a copy of this object.
boolean	contains(java.lang.Object element) Method to return if the list contains this element.
java.lang.Object	detachCopy(FetchPlanState state) Method to return a detached copy of the container.
boolean	empty() Accessor for whether the Stack is empty.
boolean	equals(java.lang.Object o) Equality operator.
void	flush() Method to flush the changes to the datastore when operating in queued mode.
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.
java.lang.Object	getValue() Accessor for the unwrapped value that we are wrapping.
int	indexOf(java.lang.Object element) Method to the position of an element.
void	initialise() Method to initialise the SCO for use.
void	initialise(java.lang.Object o, boolean forInsert, boolean forUpdate) Method to initialise the SCO from an existing value.
boolean	isEmpty() Accessor for whether the Stack is empty.
java.util.Iterator	iterator() Method to retrieve 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
QueryExpression	newQueryStatement() Method to generate a QueryStatement for the SCO.
QueryExpression	newQueryStatement(java.lang.Class candidateClass, DatastoreIdentifier candidateAlias) Method to return a QueryStatement, using the specified candidate class.
ResultObjectFactory	newResultObjectFactory(QueryExpression stmt, boolean ignoreCache, java.lang.Class resultClass, boolean useFetchPlan) Method to return a ResultObjectFactory for the SCO.
java.lang.Object	peek() Method to retrieve the element at the top of the stack.
java.lang.Object	pop() Method to remove the top element in the stack and return it.
java.lang.Object	push(java.lang.Object element) Method to push an element onto the stack and return it.
java.lang.Object	remove(int index) Method to remove an element from the Stack
boolean	remove(java.lang.Object element) Method to remove an element from the Stack
boolean	remove(java.lang.Object element, boolean allowCascadeDelete) Method to remove an element from the collection, and observe the flag for whether to allow cascade delete.
boolean	removeAll(java.util.Collection elements) Method to remove a Collection of objects from the Stack
void	removeAllElements() Method to remove all elements from the Stack.
boolean	removeElement(java.lang.Object element) Method to remove an element from the Stack
void	removeElementAt(int index) Method to remove an element from the Stack
boolean	retainAll(java.util.Collection c) Method to retain a Collection of elements (and remove all others).
java.lang.Object	set(int index, java.lang.Object element) Method to set the element at a position in the Stack
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	setElementAt(java.lang.Object element, int index) Method to set the element at a position in the Stack
int	size() Accessor for the size of the Stack.
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.Stack

search

Methods inherited from class java.util.Vector

capacity, containsAll, copyInto, elementAt, elements, ensureCapacity, firstElement, hashCode, indexOf, insertElementAt, lastElement, lastIndexOf, removeRange, setSize, toString, trimToSize

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final Localiser LOCALISER

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

Stack

public Stack(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

initialise

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

Method to initialise the SCO from an existing value.

Specified by:

initialise in interface SCO

Parameters:

o - The object to set from

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

getValue

public java.lang.Object getValue()

Accessor for the unwrapped value that we are wrapping.

Specified by:

getValue in interface SCO

Returns:

The unwrapped value

getElementType

public java.lang.Class getElementType()

Accessor for the element type.

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 SCOContainer

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

addQueuedOperation

protected void addQueuedOperation(QueuedOperation op)

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

Parameters:

op - The operation

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

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

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 of detachment state

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 candidateClass,
                                         DatastoreIdentifier candidateAlias)

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

Specified by:

newQueryStatement in interface Queryable

Parameters:

candidateClass - the candidate class

candidateAlias - Alias for the candidate

Returns:

The QueryStatement

newResultObjectFactory

public 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()

Clone operator to return 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.util.Vector

Returns:

The cloned object

contains

public boolean contains(java.lang.Object element)

Method to return if the list contains this element.

Specified by:

contains in interface java.util.Collection

Specified by:

contains in interface java.util.List

Overrides:

contains in class java.util.Vector

Parameters:

element - The element

Returns:

Whether it is contained

empty

public boolean empty()

Accessor for whether the Stack is empty.

Overrides:

empty in class java.util.Stack

Returns:

Whether it is empty.

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.Vector

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

Overrides:

get in class java.util.Vector

Parameters:

index - The item to retrieve

Returns:

The element at that position.

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.Vector

Parameters:

element - The element.

Returns:

The position.

isEmpty

public boolean isEmpty()

Accessor for whether the Stack 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.Vector

Returns:

Whether it is empty.

iterator

public java.util.Iterator iterator()

Method to retrieve 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

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.Vector

Parameters:

element - The element

Returns:

The last position of this element in the List.

peek

public java.lang.Object peek()

Method to retrieve the element at the top of the stack.

Overrides:

peek in class java.util.Stack

Returns:

The element at the top of the stack

size

public int size()

Accessor for the size of the Stack.

Specified by:

size in interface java.util.Collection

Specified by:

size in interface java.util.List

Overrides:

size in class java.util.Vector

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.Vector

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.Vector

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.Vector

Parameters:

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

Returns:

The array

add

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

Method to add an element to a position in the Stack

Specified by:

add in interface java.util.List

Overrides:

add in class java.util.Vector

Parameters:

index - The position

element - The new element

add

public boolean add(java.lang.Object element)

Method to add an element to the Stack

Specified by:

add in interface java.util.Collection

Specified by:

add in interface java.util.List

Overrides:

add in class java.util.Vector

Parameters:

element - The new element

Returns:

Whether it was added ok.

addElement

public void addElement(java.lang.Object element)

Method to add an element to the Stack

Overrides:

addElement in class java.util.Vector

Parameters:

element - The new element

addAll

public boolean addAll(java.util.Collection elements)

Method to add a Collection to the Stack

Specified by:

addAll in interface java.util.Collection

Specified by:

addAll in interface java.util.List

Overrides:

addAll in class java.util.Vector

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 to a position in the Stack

Specified by:

addAll in interface java.util.List

Overrides:

addAll in class java.util.Vector

Parameters:

index - Position to insert the collection.

elements - The collection

Returns:

Whether it was added ok.

clear

public void clear()

Method to clear the Stack

Specified by:

clear in interface java.util.Collection

Specified by:

clear in interface java.util.List

Overrides:

clear in class java.util.Vector

pop

public java.lang.Object pop()

Method to remove the top element in the stack and return it.

Overrides:

pop in class java.util.Stack

Returns:

The top element that was in the Stack (now removed).

push

public java.lang.Object push(java.lang.Object element)

Method to push an element onto the stack and return it.

Overrides:

push in class java.util.Stack

Parameters:

element - The element to push onto the stack.

Returns:

The element that was pushed onto the Stack

remove

public boolean remove(java.lang.Object element)

Method to remove an element from the Stack

Specified by:

remove in interface java.util.Collection

Specified by:

remove in interface java.util.List

Overrides:

remove in class java.util.Vector

Parameters:

element - The element

Returns:

Whether the element was removed

remove

public boolean remove(java.lang.Object element,
                      boolean allowCascadeDelete)

Method to remove an element from the collection, and observe the flag for whether to allow cascade delete.

Specified by:

remove in interface SCOCollection

Parameters:

element - The element

allowCascadeDelete - Whether to allow cascade delete

Returns:

Whether the element was removed

removeAll

public boolean removeAll(java.util.Collection elements)

Method to remove a Collection of objects from the Stack

Specified by:

removeAll in interface java.util.Collection

Specified by:

removeAll in interface java.util.List

Overrides:

removeAll in class java.util.Vector

Parameters:

elements - The Collection

Returns:

Whether the collection of elements were removed

removeElement

public boolean removeElement(java.lang.Object element)

Method to remove an element from the Stack

Overrides:

removeElement in class java.util.Vector

Parameters:

element - The element

Returns:

Whether the element was removed

remove

public java.lang.Object remove(int index)

Method to remove an element from the Stack

Specified by:

remove in interface java.util.List

Overrides:

remove in class java.util.Vector

Parameters:

index - The element position.

Returns:

The object that was removed

removeElementAt

public void removeElementAt(int index)

Method to remove an element from the Stack

Overrides:

removeElementAt in class java.util.Vector

Parameters:

index - The element position.

removeAllElements

public void removeAllElements()

Method to remove all elements from the Stack. Same as clear().

Overrides:

removeAllElements in class java.util.Vector

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.Vector

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 Stack

Specified by:

set in interface java.util.List

Overrides:

set in class java.util.Vector

Parameters:

index - The position

element - The new element

Returns:

The element previously at that position

setElementAt

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

Method to set the element at a position in the Stack

Overrides:

setElementAt in class java.util.Vector

Parameters:

element - The new element

index - The 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