Module org.eclipse.persistence.core

Package org.eclipse.persistence.descriptors

Class TimestampLockingPolicy

java.lang.Object

org.eclipse.persistence.descriptors.VersionLockingPolicy

org.eclipse.persistence.descriptors.TimestampLockingPolicy

All Implemented Interfaces:

Serializable, Cloneable, OptimisticLockingPolicy

public class TimestampLockingPolicy
extends VersionLockingPolicy

Purpose: Used to allow a single version timestamp to be used for optimistic locking.

Since:

TOPLink/Java 2.0

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

OptimisticLockingPolicy.LockOnChange

Field Summary

Fields

Modifier and Type	Field	Description
static final int	LOCAL_TIME
protected int	retrieveTimeFrom
static final int	SERVER_TIME

Fields inherited from class org.eclipse.persistence.descriptors.VersionLockingPolicy

cachedExpression, descriptor, IN_CACHE, IN_OBJECT, isCascaded, lockMapping, lockOnChangeMode, lockValueStored, writeLockField

Constructor Summary

Constructors

Constructor	Description
TimestampLockingPolicy()	PUBLIC: Create a new TimestampLockingPolicy.
TimestampLockingPolicy(String fieldName)	PUBLIC: Create a new TimestampLockingPolicy.
TimestampLockingPolicy(DatabaseField field)	INTERNAL: Create a new TimestampLockingPolicy.

Method Summary

Modifier and Type	Method	Description
int	compareWriteLockValues(Object value1, Object value2)	INTERNAL: This method compares two writeLockValues.
<T> T	getBaseValue()	INTERNAL: This is the base value that is older than all other values, it is used in the place of null in some situations.
protected <T> Class<T>	getDefaultLockingFieldType()	INTERNAL: Return the default timestamp locking filed java type, default is Timestamp.
protected <T> T	getInitialWriteValue(AbstractSession session)	INTERNAL: returns the initial locking value
<T> T	getNewLockValue(ModifyQuery query)	INTERNAL: Returns the new Timestamp value.
<T> T	getValueToPutInCache(AbstractRecord row, AbstractSession session)	INTERNAL: Return the value that should be stored in the identity map.
int	getVersionDifference(Object currentValue, Object domainObject, Object primaryKeys, AbstractSession session)	INTERNAL: Return the number of versions different between these objects.
Expression	getWriteLockUpdateExpression(ExpressionBuilder builder, AbstractSession session)	INTERNAL: Return an expression that updates the write lock
<T> T	getWriteLockValue(Object domainObject, Object primaryKey, AbstractSession session)	INTERNAL: This method will return the optimistic lock value for the object.
protected Number	incrementWriteLockValue(Number numberValue)	INTERNAL: Timestamp versioning should not be able to do this.
boolean	isNewerVersion(Object firstLockFieldValue, Object secondWriteLockFieldValue)	INTERNAL: Compares two values.
boolean	isNewerVersion(Object currentValue, Object domainObject, Object primaryKey, AbstractSession session)	INTERNAL: Compares the value with the value from the object (or cache).
boolean	isNewerVersion(AbstractRecord databaseRow, Object domainObject, Object primaryKey, AbstractSession session)	INTERNAL: Compares the value from the row and from the object (or cache).
void	setUsesServerTime(boolean usesServerTime)	PUBLIC: Set if policy uses server time.
void	useLocalTime()	PUBLIC: set this policy to get the time from the local machine.
void	useServerTime()	PUBLIC: set this policy to get the time from the server.
boolean	usesLocalTime()	PUBLIC: Return true if policy uses local time.
boolean	usesServerTime()	PUBLIC: Return true if policy uses server time.

Methods inherited from class org.eclipse.persistence.descriptors.VersionLockingPolicy

addLockFieldsToUpdateRow, addLockValuesToTranslationRow, buildDeleteExpression, buildExpression, buildUpdateExpression, clone, getDescriptor, getLockOnChangeMode, getUnmappedFields, getVersionMapping, getWriteLockField, getWriteLockFieldName, initialize, initializeProperties, isCascaded, isStoredInCache, isStoredInObject, lockValueFromObject, mergeIntoParentCache, mergeIntoParentCache, setDescriptor, setIsCascaded, setIsStoredInCache, setLockOnChangeMode, setupWriteFieldsForInsert, setWriteLockField, setWriteLockFieldName, shouldUpdateVersionOnMappingChange, shouldUpdateVersionOnOwnedMappingChange, storeInCache, storeInObject, supportsWriteLockValuesComparison, updateObjectWithWriteValue, updateRowAndObjectForUpdate, updateWriteLockValueForWrite, validateDelete, validateUpdate, writeLockValueIntoRow

Methods inherited from class java.lang.Object

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

Field Details

retrieveTimeFrom

protected int retrieveTimeFrom

SERVER_TIME

public static final int SERVER_TIME

See Also:

• Constant Field Values

LOCAL_TIME

public static final int LOCAL_TIME

See Also:

• Constant Field Values

Constructor Details

TimestampLockingPolicy

public TimestampLockingPolicy()

PUBLIC: Create a new TimestampLockingPolicy. Defaults to using the time retrieved from the server.

TimestampLockingPolicy

public TimestampLockingPolicy(String fieldName)

PUBLIC: Create a new TimestampLockingPolicy. Defaults to using the time retrieved from the server.

Parameters:

fieldName - the field where the write lock value will be stored.

TimestampLockingPolicy

public TimestampLockingPolicy(DatabaseField field)

INTERNAL: Create a new TimestampLockingPolicy. Defaults to using the time retrieved from the server.

Parameters:

field - the field where the write lock value will be stored.

Method Details

compareWriteLockValues

public int compareWriteLockValues(Object value1,
 Object value2)

INTERNAL: This method compares two writeLockValues. The writeLockValues should be non-null and of type java.sql.Timestamp. Returns: -1 if value1 is less (older) than value2; 0 if value1 equals value2; 1 if value1 is greater (newer) than value2. Throws: NullPointerException if the passed value is null; ClassCastException if the passed value is of a wrong type.

Specified by:

compareWriteLockValues in interface OptimisticLockingPolicy

Overrides:

compareWriteLockValues in class VersionLockingPolicy

getDefaultLockingFieldType

protected <T> Class<T> getDefaultLockingFieldType()

INTERNAL: Return the default timestamp locking filed java type, default is Timestamp.

Overrides:

getDefaultLockingFieldType in class VersionLockingPolicy

getBaseValue

public <T> T getBaseValue()

INTERNAL: This is the base value that is older than all other values, it is used in the place of null in some situations.

Specified by:

getBaseValue in interface OptimisticLockingPolicy

Overrides:

getBaseValue in class VersionLockingPolicy

getInitialWriteValue

protected <T> T getInitialWriteValue(AbstractSession session)

INTERNAL: returns the initial locking value

Overrides:

getInitialWriteValue in class VersionLockingPolicy

getNewLockValue

public <T> T getNewLockValue(ModifyQuery query)

INTERNAL: Returns the new Timestamp value.

Overrides:

getNewLockValue in class VersionLockingPolicy

getValueToPutInCache

public <T> T getValueToPutInCache(AbstractRecord row,
 AbstractSession session)

INTERNAL: Return the value that should be stored in the identity map. If the value is stored in the object, then return a null.

Specified by:

getValueToPutInCache in interface OptimisticLockingPolicy

Overrides:

getValueToPutInCache in class VersionLockingPolicy

getVersionDifference

public int getVersionDifference(Object currentValue,
 Object domainObject,
 Object primaryKeys,
 AbstractSession session)

INTERNAL: Return the number of versions different between these objects.

Specified by:

getVersionDifference in interface OptimisticLockingPolicy

Overrides:

getVersionDifference in class VersionLockingPolicy

Parameters:

currentValue - the new lock value

domainObject - the object containing the version to be compared to

primaryKeys - a vector containing the primary keys of the domainObject

session - the session to be used with the comparison

getWriteLockValue

public <T> T getWriteLockValue(Object domainObject,
 Object primaryKey,
 AbstractSession session)

INTERNAL: This method will return the optimistic lock value for the object.

Specified by:

getWriteLockValue in interface OptimisticLockingPolicy

Overrides:

getWriteLockValue in class VersionLockingPolicy

getWriteLockUpdateExpression

public Expression getWriteLockUpdateExpression(ExpressionBuilder builder,
 AbstractSession session)

INTERNAL: Return an expression that updates the write lock

Specified by:

getWriteLockUpdateExpression in interface OptimisticLockingPolicy

Overrides:

getWriteLockUpdateExpression in class VersionLockingPolicy

incrementWriteLockValue

protected Number incrementWriteLockValue(Number numberValue)

INTERNAL: Timestamp versioning should not be able to do this. Override the superclass behavior.

Overrides:

incrementWriteLockValue in class VersionLockingPolicy

isNewerVersion

public boolean isNewerVersion(Object currentValue,
 Object domainObject,
 Object primaryKey,
 AbstractSession session)

INTERNAL: Compares the value with the value from the object (or cache). Will return true if the currentValue is newer than the domainObject.

Specified by:

isNewerVersion in interface OptimisticLockingPolicy

Overrides:

isNewerVersion in class VersionLockingPolicy

isNewerVersion

public boolean isNewerVersion(AbstractRecord databaseRow,
 Object domainObject,
 Object primaryKey,
 AbstractSession session)

INTERNAL: Compares the value from the row and from the object (or cache). Will return true if the row is newer than the object.

Specified by:

isNewerVersion in interface OptimisticLockingPolicy

Overrides:

isNewerVersion in class VersionLockingPolicy

isNewerVersion

public boolean isNewerVersion(Object firstLockFieldValue,
 Object secondWriteLockFieldValue)

INTERNAL: Compares two values. Will return true if the firstLockFieldValue is newer than the secondWriteLockFieldValue.

Overrides:

isNewerVersion in class VersionLockingPolicy

setUsesServerTime

public void setUsesServerTime(boolean usesServerTime)

PUBLIC: Set if policy uses server time.

useLocalTime

public void useLocalTime()

PUBLIC: set this policy to get the time from the local machine.

useServerTime

public void useServerTime()

PUBLIC: set this policy to get the time from the server.

usesLocalTime

public boolean usesLocalTime()

PUBLIC: Return true if policy uses local time.

usesServerTime

public boolean usesServerTime()

PUBLIC: Return true if policy uses server time.