org.jpox.store.rdbms.poid
Class MaxPoidGenerator

java.lang.Object
  org.jpox.store.poid.AbstractPoidGenerator
      org.jpox.store.poid.AbstractDatastorePoidGenerator
          org.jpox.store.rdbms.poid.AbstractRDBMSPoidGenerator
              org.jpox.store.rdbms.poid.MaxPoidGenerator

All Implemented Interfaces:

javax.jdo.datastore.Sequence, PoidGenerator

public class MaxPoidGenerator
extends AbstractRDBMSPoidGenerator

This generator for Relational Databases uses the "select max(column) from table" strategy. The block Poid size is limited to 1. MaxPoidGenerator works with numbers, so clients using this Poid must cast the ID to Long *

Required user properties

Optional user properties

Version:

$Revision: 1.8 $

Field Summary

protected static Localiser

LOCALISER_RDBMS

Fields inherited from class org.jpox.store.rdbms.poid.AbstractRDBMSPoidGenerator

connection

Fields inherited from class org.jpox.store.poid.AbstractDatastorePoidGenerator

connectionProvider, storeMgr

Fields inherited from class org.jpox.store.poid.AbstractPoidGenerator

allocationSize, initialValue, LOCALISER, name, poidBlock, properties

Constructor Summary

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

Method Summary

PoidBlock

reserveBlock(long size) Method to reserve a block of identities.

Methods inherited from class org.jpox.store.rdbms.poid.AbstractRDBMSPoidGenerator

obtainPoidBlock, requiresConnection

Methods inherited from class org.jpox.store.poid.AbstractDatastorePoidGenerator

setConnectionProvider, setStoreManager

Methods inherited from class org.jpox.store.poid.AbstractPoidGenerator

allocate, createRepository, current, currentValue, getName, next, nextValue, obtainPoidBlock, requiresRepository, reserveBlock

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER_RDBMS

protected static final Localiser LOCALISER_RDBMS

Constructor Detail

MaxPoidGenerator

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

Constructor.

Parameters:

name - Symbolic name for this generator

props - Properties defining the behaviour of this generator

Method Detail

reserveBlock

public PoidBlock reserveBlock(long size)

Method to reserve a block of identities. Note : Only allocates a single id always.

Specified by:

reserveBlock in class AbstractPoidGenerator

Parameters:

size - The block size

Returns:

The reserved block