Package org.datanucleus.metadata

Enum VersionStrategy

java.lang.Object

java.lang.Enum<VersionStrategy>

org.datanucleus.metadata.VersionStrategy

All Implemented Interfaces:

Serializable, Comparable<VersionStrategy>

public enum VersionStrategy
extends Enum<VersionStrategy>

Three common strategies for versioning instances are supported by standard metadata. These include state-comparison, timestamp, and version-number.

• date-time involves comparing the value in a date-time column in the table. The first time in a transaction the row is updated, the timestamp value is updated to the current time.
• version-number involves comparing the value in a numeric column in the table. The first time in a transaction the row is updated, the version-number column value is incremented.
• state-image involves comparing the values in specific columns to determine if the database row was changed.

Enum Constant Summary

Enum Constants

Enum Constant	Description
DATE_TIME
NONE
STATE_IMAGE
VERSION_NUMBER

Method Summary

Modifier and Type	Method	Description
static VersionStrategy	getVersionStrategy(String value)	Return VersionStrategy from String.
String	toString()
static VersionStrategy	valueOf(String name)	Returns the enum constant of this type with the specified name.
static VersionStrategy[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

NONE

public static final VersionStrategy NONE

VERSION_NUMBER

public static final VersionStrategy VERSION_NUMBER

DATE_TIME

public static final VersionStrategy DATE_TIME

STATE_IMAGE

public static final VersionStrategy STATE_IMAGE

Method Detail

values

public static VersionStrategy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (VersionStrategy c : VersionStrategy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static VersionStrategy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

toString

public String toString()

Overrides:

toString in class Enum<VersionStrategy>

getVersionStrategy

public static VersionStrategy getVersionStrategy(String value)

Return VersionStrategy from String.

Parameters:

value - strategy attribute value

Returns:

Instance of VersionStrategy. If value invalid, return null.