org.jpox.store.poid
Class AbstractPoidGenerator

java.lang.Object
  org.jpox.store.poid.AbstractPoidGenerator

All Implemented Interfaces:

PoidGenerator

Direct Known Subclasses:

AbstractDatastorePoidGenerator, AbstractUIDPoidGenerator, TimestampPoidGenerator, TimestampValuePoidGenerator

public abstract class AbstractPoidGenerator
extends java.lang.Object
implements PoidGenerator

Abstract POID generator.

Version:

$Revision: 1.9 $

Field Summary

protected int	allocationSize Allocation size
protected int	initialValue Initial value (of the first id).
protected static Localiser	LOCALISER Localisation of messages
protected java.lang.String	name Symbolic name for the sequence.
protected PoidBlock	poidBlock The current block of ids that have been reserved.
protected java.util.Properties	properties Properties controlling the generator behaviour.

Constructor Summary

AbstractPoidGenerator(java.lang.String name, java.util.Properties props)
Constructor.

Method Summary

void	allocate(int additional) Method to allocate a number of values into the block.
protected boolean	createRepository() Method to create any needed repository for the ids.
java.lang.Object	current() Accessor for the current value allocated.
long	currentValue() Accessor for the current element in the sequence as a long.
java.lang.String	getName() Accessor for the symbolic name for this generator.
static java.lang.Class	getStorageClass() Accessor for the storage class for POIDs generated with this generator.
java.lang.Object	next() Get next value from the reserved block of values.
long	nextValue() Accessor for the next element in the sequence as a long.
protected PoidBlock	obtainPoidBlock() Get a new PoidBlock with the default number of ids.
protected PoidBlock	obtainPoidBlock(int number) Get a new PoidBlock with the specified number of ids.
protected boolean	requiresRepository() Indicator for whether the generator requires its own repository.
protected PoidBlock	reserveBlock() Method to reserve a default sized block of identities.
protected abstract PoidBlock	reserveBlock(long size) Method to reserve a blobk of "size" ids.

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final Localiser LOCALISER

Localisation of messages

name

protected java.lang.String name

Symbolic name for the sequence.

properties

protected java.util.Properties properties

Properties controlling the generator behaviour.

allocationSize

protected int allocationSize

Allocation size

initialValue

protected int initialValue

Initial value (of the first id).

poidBlock

protected PoidBlock poidBlock

The current block of ids that have been reserved.

Constructor Detail

AbstractPoidGenerator

public AbstractPoidGenerator(java.lang.String name,
                             java.util.Properties props)

Constructor. JPOX Core will pass the following properties (as a minimum) through this constructor.

• class-name : Name of the class whose object is being inserted.
• root-class-name : Name of the root class in this inheritance tree
• field-name : Name of the field with the strategy (unless datastore identity field)
• catalog-name : Catalog of the table (if specified)
• schema-name : Schema of the table (if specified)
• table-name : Name of the root table for this inheritance tree (containing the field).
• column-name : Name of the column in the table (for the field)
• sequence-name : Name of the sequence (if specified in MetaData as "sequence)

Parameters:

name - Symbolic name for this generator

props - Properties controlling the behaviour of the generator (or null if not required).

Method Detail

getStorageClass

public static java.lang.Class getStorageClass()

Accessor for the storage class for POIDs generated with this generator.

Returns:

Storage class (e.g Long.class)

getName

public java.lang.String getName()

Accessor for the symbolic name for this generator.

Specified by:

getName in interface PoidGenerator

Returns:

Symbolic name for the generator.

next

public java.lang.Object next()

Get next value from the reserved block of values.

Specified by:

next in interface PoidGenerator

Returns:

The next value

current

public java.lang.Object current()

Accessor for the current value allocated. Returns null if none are allocated

Specified by:

current in interface PoidGenerator

Returns:

The current value

nextValue

public long nextValue()

Accessor for the next element in the sequence as a long.

Specified by:

nextValue in interface PoidGenerator

Returns:

The next element

Throws:

JPOXDataStoreException - Thrown if not numeric

currentValue

public long currentValue()

Accessor for the current element in the sequence as a long.

Specified by:

currentValue in interface PoidGenerator

Returns:

The current element

Throws:

JPOXDataStoreException - Thrown if not numeric

allocate

public void allocate(int additional)

Method to allocate a number of values into the block. If the block already exists and has remaining values, the additional values are added to the block.

Specified by:

allocate in interface PoidGenerator

Parameters:

additional - The number to allocate

obtainPoidBlock

protected PoidBlock obtainPoidBlock()

Get a new PoidBlock with the default number of ids.

Returns:

the PoidBlock

obtainPoidBlock

protected PoidBlock obtainPoidBlock(int number)

Get a new PoidBlock with the specified number of ids.

Parameters:

number - The number of additional ids required

Returns:

the PoidBlock

reserveBlock

protected PoidBlock reserveBlock()

Method to reserve a default sized block of identities.

Returns:

The reserved block

reserveBlock

protected abstract PoidBlock reserveBlock(long size)

Method to reserve a blobk of "size" ids.

Parameters:

size - Number of ids to reserve

Returns:

The allocated block

requiresRepository

protected boolean requiresRepository()

Indicator for whether the generator requires its own repository. AbstractPoidGenerator returns false and this should be overridden by all generators requiring a repository.

Returns:

Whether a repository is required.

createRepository

protected boolean createRepository()

Method to create any needed repository for the ids. AbstractPoidGenerator just returns true and should be overridden by any implementing generator requiring its own repository.

Returns:

If all is ready for use