org.jpox.metadata
Class VersionStrategy

java.lang.Object
  org.jpox.metadata.VersionStrategy

All Implemented Interfaces:

java.io.Serializable

public class VersionStrategy
extends java.lang.Object
implements java.io.Serializable

Three common strategies for versioning instances are supported by standard metadata. These include state-comparison, timestamp, and version-number. state-image involves comparing the values in specific columns to determine if the database row was changed. 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.

Version:

$Revision: 1.4 $

Author:

Erik Bengtson

See Also:

Serialized Form

Field Summary

static VersionStrategy	DATE_TIME strategy="date-time"
static VersionStrategy	STATE_IMAGE strategy="state-image"
static VersionStrategy	VERSION_NUMBER strategy="version-number"

Method Summary

boolean	equals(java.lang.Object o) Indicates whether some other object is "equal to" this one.
protected int	getType()
static VersionStrategy	getVersionStrategy(java.lang.String value) Return VersionStrategy from String.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Field Detail

STATE_IMAGE

public static final VersionStrategy STATE_IMAGE

strategy="state-image"

DATE_TIME

public static final VersionStrategy DATE_TIME

strategy="date-time"

VERSION_NUMBER

public static final VersionStrategy VERSION_NUMBER

strategy="version-number"

Method Detail

equals

public boolean equals(java.lang.Object o)

Indicates whether some other object is "equal to" this one.

Overrides:

equals in class java.lang.Object

Parameters:

o - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.

getType

protected int getType()

getVersionStrategy

public static VersionStrategy getVersionStrategy(java.lang.String value)

Return VersionStrategy from String.

Parameters:

value - strategy attribute value

Returns:

Instance of VersionStrategy. If value invalid, return null.