org.datanucleus.store

Class VersionHelper

java.lang.Object

org.datanucleus.store.VersionHelper

public class VersionHelper
extends Object

Helper methods for handling optimistic versioning.

Field Summary

Fields

Modifier and Type	Field and Description
protected static Localiser	LOCALISER Localiser for messages.

Constructor Summary

Constructors

Constructor and Description
VersionHelper()

Method Summary

Methods

Modifier and Type	Method and Description
static Object	getNextVersion(VersionStrategy versionStrategy, Object currentVersion) Convenience method to provide the next version, using the version strategy given the supplied current version.
static void	performVersionCheck(ObjectProvider op, Object versionDatastore, VersionMetaData versionMetaData) Perform an optimistic version check on the passed object, against the passed version in the datastore.

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

Localiser for messages.

Constructor Detail

VersionHelper

public VersionHelper()

Method Detail

performVersionCheck

public static void performVersionCheck(ObjectProvider op,
                       Object versionDatastore,
                       VersionMetaData versionMetaData)

Perform an optimistic version check on the passed object, against the passed version in the datastore.

Parameters:

op - ObjectProvider of the object to check

versionDatastore - Version of the object in the datastore

versionMetaData - VersionMetaData to use for checking

Throws:

NucleusUserException - thrown when an invalid strategy is specified

NucleusOptimisticException - thrown when the version check fails

getNextVersion

public static Object getNextVersion(VersionStrategy versionStrategy,
                    Object currentVersion)

Convenience method to provide the next version, using the version strategy given the supplied current version.

Parameters:

versionStrategy - Version strategy

currentVersion - The current version

Returns:

The next version

Throws:

NucleusUserException - Thrown if the strategy is not supported.