atg.service.idgen

Interface IdGenerator

All Known Implementing Classes:

AbstractSequentialIdGenerator, FileIdGenerator, ObfuscatedSQLIdGenerator, PersistentIdGenerator, SQLIdGenerator, TransientIdGenerator

public interface IdGenerator

Facility that generates ids as both Strings and longs. IdGenerators support the concept of an id space. Ids are unique within an id space, but not necessarily across id spaces. This allows a single id generator to generate ids for a related set of objects.

Users of an IdGenerator need not be aware that id spaces exist. All id generators support a default id space which is assumed when no other id space is specified. Additionality, id generators are responsible for initializing the default id space.

Implementations add functionality like: the ability to generate id that are unique in a distributed system; and user defined hooks to modify or filter generated ids.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	CLASS_VERSION Class version string

Method Summary

Modifier and Type	Method and Description
boolean	addIdSpace(IdSpace pSpace) Add an id space to the id generator.
long	generateLongId() Generate a long id in the default name space.
long	generateLongId(java.lang.String pIdSpace) Generate a long id in the specified name space.
java.lang.String	generateStringId() Generate a String id in the default name space.
java.lang.String	generateStringId(java.lang.String pIdSpace) Generate a string id in the specified name space.
boolean	getAutoCreate() Get property autoCreate
IdSpace	getDefaultIdSpace() Get property DefaultIdSpace
IdSpace	getIdSpace(java.lang.String pName) Get a copy of the named id space from the generator.
java.util.Map	getIdSpaces() Get a copy of all the spaces defined in the generator.
void	initialize() Initialize the generator, preparing it to generate ids.
boolean	isAutoCreate() Test property autoCreate
void	removeAllIdSpaces() Remove all id spaces from the id generator.
boolean	removeIdSpace(IdSpace pSpace) Remove an id space from the id generator.
void	setAutoCreate(boolean pAutoCreate) Set property autoCreate

Field Detail

CLASS_VERSION

static final java.lang.String CLASS_VERSION

Class version string

See Also:

Constant Field Values

Method Detail

getDefaultIdSpace

IdSpace getDefaultIdSpace()

Get property DefaultIdSpace

Returns:

DefaultIdSpace

generateLongId

long generateLongId()
             throws IdGeneratorException

Generate a long id in the default name space.

Returns:

the id

Throws:

IdGeneratorException - if there is an error generating the id

generateStringId

java.lang.String generateStringId()
                           throws IdGeneratorException

Generate a String id in the default name space.

Returns:

the id

Throws:

IdGeneratorException - if there is an error generating the id

generateLongId

long generateLongId(java.lang.String pIdSpace)
             throws IdGeneratorException

Generate a long id in the specified name space.

Parameters:

pIdSpace - name of id space to use, null means use the anonymous, default space

Returns:

the new id, or -1 if the id space is not recognized

Throws:

IdGeneratorException - if there is an error generating the id

generateStringId

java.lang.String generateStringId(java.lang.String pIdSpace)
                           throws IdGeneratorException

Generate a string id in the specified name space.

Parameters:

pIdSpace - name of id space to use, null means use the anonymous, default space

Returns:

the new id

Throws:

IdGeneratorException - if there is an error generating the id

getIdSpace

IdSpace getIdSpace(java.lang.String pName)

Get a copy of the named id space from the generator.

Parameters:

name - of id space to get

Returns:

a copy of the named id space, or null if not found

getIdSpaces

java.util.Map getIdSpaces()

Get a copy of all the spaces defined in the generator.

Returns:

a Map of all the id spaces defined in the generator. The keys of the Map are the names of the spaces, and the values are IdSpace objects

addIdSpace

boolean addIdSpace(IdSpace pSpace)
            throws IdGeneratorException

Add an id space to the id generator. The id space must not be null.

Parameters:

pSpace - space to add, cannot be null

Returns:

true if the space is added, or false if a space with the same name already exists in this id generator

Throws:

IdGeneratorException - if there is trouble adding the space

setAutoCreate

void setAutoCreate(boolean pAutoCreate)

Set property autoCreate

Parameters:

pAutoCreate - new value to set

getAutoCreate

boolean getAutoCreate()

Get property autoCreate

Returns:

autoCreate

isAutoCreate

boolean isAutoCreate()

Test property autoCreate

Returns:

autoCreate

removeIdSpace

boolean removeIdSpace(IdSpace pSpace)
               throws IdGeneratorException

Remove an id space from the id generator. The id space must not be null. Removing an id space causes information associated with that id space to be lost. Take care that no facility is still using an id space before removing it.

Parameters:

pSpace - space to remove, cannot be null

Returns:

true if the space is removed, or false if it is not known to this id generator

Throws:

java.lang.IllegalArgumentException - if the specified space is null or otherwise invalid

IdGeneratorException - if there is trouble removing the space

removeAllIdSpaces

void removeAllIdSpaces()
                throws IdGeneratorException

Remove all id spaces from the id generator. Removing id spaces causes information associated with those id spaces to be lost. Take care that no facility is still using any of the id spaces before removing them.

Throws:

IdGeneratorException - if there is trouble removing the spaces

initialize

void initialize()
         throws IdGeneratorException

Initialize the generator, preparing it to generate ids. After initialize() completes, the generator is ready for use. Therefore initialize must at the least ensure that the default id space is set up.

Throws:

IdGeneratorException - if there is an error initializing