org.cristalise.kernel.collection

Class Collection<E extends CollectionMember>

java.lang.Object

org.cristalise.kernel.collection.Collection<E>

All Implemented Interfaces:

C2KLocalObject

Direct Known Subclasses:

Aggregation, Dependency

public abstract class Collection<E extends CollectionMember>
extends Object
implements C2KLocalObject

Collections are Item local objects that reference other Items.

In parallel with the OO meta-model, Items can be linked to other Items in different ways. These links are modelled with Collections, which are local objects stored in an Item which reference a number of other Items in the same server. The Collections holds a CollectionMember, sometimes known as a slot, to reference each Item and store additional information about the link.

Features:

• Typing - Collections can restrict membership of based on type information derived from Item, Property and Collection descriptions. This restriction may be per-slot or apply to the whole Collection.
• Fixed or flexible slots - The CollectionMember objects of a Collection may be empty, individually typed, or created and removed as required, simulating either array, structures or lists.
• Layout - Collections can include a GraphModel to lay out its slots on a two-dimensional canvas, for modelling real world compositions.

Collections are managed through predefined steps.

Field Summary

Fields

Modifier and Type	Field and Description
static short	EMPTY
protected CollectionMemberList<E>	mMembers
protected String	mName
protected Integer	mVersion

Constructor Summary

Constructors

Constructor and Description
Collection()

Method Summary

Methods

Modifier and Type	Method and Description
abstract E	addMember(ItemPath itemPath, CastorHashMap props, String classProps) Add a member to this collection, with the given property and class properties and optionally an Item to assign, which may be null if the collection allows empty slots.
boolean	contains(ItemPath itemPath)
boolean	equals(Object obj)
String	getClusterType()
int	getCounter() Fetch the current highest member ID of the collection.
String	getDescVer(E mem) Gets the description version referenced by the given collection member.
E	getMember(int memberId) Find collection member by integer ID
CollectionMemberList<E>	getMembers()
String	getName()
Integer	getVersion() Get the collection version.
String	getVersionName() Get the version name for storage, which is 'last' unless the version number is set.
int	hashCode()
boolean	isFull() Check if all slots have an assigned Item
abstract void	removeMember(int memberId) Removes the slot with the given ID from the collection.
void	setMembers(CollectionMemberList<E> newMembers)
void	setName(String name) Sets the collection name
void	setVersion(Integer mVersion) Set a named version for this collection.
int	size()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY

public static final short EMPTY

See Also:

Constant Field Values

mMembers

protected CollectionMemberList<E extends CollectionMember> mMembers

mName

protected String mName

mVersion

protected Integer mVersion

Constructor Detail

Collection

public Collection()

Method Detail

getCounter

public int getCounter()

Fetch the current highest member ID of the collection. This is found by scanning all the current members and kept in the mCounter field, but is not persistent.

Returns:

the current highest member ID

size

public int size()

Returns:

The total number of slots in this collection, including empty ones

setName

public void setName(String name)

Sets the collection name

Specified by:

setName in interface C2KLocalObject

getName

public String getName()

Specified by:

getName in interface C2KLocalObject

Returns:

The collection's name

getVersion

public Integer getVersion()

Get the collection version. Null if not set, and will be stored as 'last'

Returns:

Integer version

setVersion

public void setVersion(Integer mVersion)

Set a named version for this collection. Must be an integer or null. Named versions will be stored separately to the current version ('last') and should not change once saved.

Parameters:

Integer - version

getVersionName

public String getVersionName()

Get the version name for storage, which is 'last' unless the version number is set.

Returns:

getClusterType

public String getClusterType()

Specified by:

getClusterType in interface C2KLocalObject

setMembers

public void setMembers(CollectionMemberList<E> newMembers)

contains

public boolean contains(ItemPath itemPath)

getDescVer

public String getDescVer(E mem)

Gets the description version referenced by the given collection member. Assumes 'last' if version not given.

Parameters:

mem - The member in question

Returns:

String version tag

isFull

public boolean isFull()

Check if all slots have an assigned Item

Returns:

boolean

getMember

public E getMember(int memberId)
                                     throws ObjectNotFoundException

Find collection member by integer ID

Parameters:

memberId - to find

Returns:

the CollectionMember with that ID

Throws:

ObjectNotFoundException - when the ID wasn't found

getMembers

public CollectionMemberList<E> getMembers()

addMember

public abstract E addMember(ItemPath itemPath,
          CastorHashMap props,
          String classProps)
                                              throws InvalidCollectionModification,
                                                     ObjectAlreadyExistsException

Add a member to this collection, with the given property and class properties and optionally an Item to assign, which may be null if the collection allows empty slots.

Parameters:

itemPath - the Item to assign to the new slot. Optional for collections that allow empty slots

props - the Properties of the new member

classProps - the names of the properties that dictate the type of assigned Items.

Returns:

the new CollectionMember instance

Throws:

InvalidCollectionModification - when the assignment was invalid because of collection constraints, such as global type constraints, or not allowing empty slots.

ObjectAlreadyExistsException - some collections don't allow multiple slots assigned to the same Item, and throw this Exception if it is attempted

removeMember

public abstract void removeMember(int memberId)
                           throws ObjectNotFoundException

Removes the slot with the given ID from the collection.

Parameters:

memberId - to remove

Throws:

ObjectNotFoundException - when there was no slot with this ID found.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object