Class TimestampLockingPolicy

  • All Implemented Interfaces:
    Serializable, Cloneable, org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    public class TimestampLockingPolicy
    extends VersionLockingPolicy

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

    See Also:
    Serialized Form
    Since:
    TOPLink/Java 2.0
    • Constructor Detail

      • 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​(org.eclipse.persistence.internal.helper.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 Detail

      • 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 org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        compareWriteLockValues in class VersionLockingPolicy
      • getBaseValue

        public Object 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 org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        getBaseValue in class VersionLockingPolicy
      • getInitialWriteValue

        protected Object getInitialWriteValue​(org.eclipse.persistence.internal.sessions.AbstractSession session)
        INTERNAL: returns the initial locking value
        Overrides:
        getInitialWriteValue in class VersionLockingPolicy
      • getValueToPutInCache

        public Object getValueToPutInCache​(org.eclipse.persistence.internal.sessions.AbstractRecord row,
                                           org.eclipse.persistence.internal.sessions.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 org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        getValueToPutInCache in class VersionLockingPolicy
      • getVersionDifference

        public int getVersionDifference​(Object currentValue,
                                        Object domainObject,
                                        Object primaryKeys,
                                        org.eclipse.persistence.internal.sessions.AbstractSession session)
        INTERNAL: Return the number of versions different between these objects.
        Specified by:
        getVersionDifference in interface org.eclipse.persistence.internal.descriptors.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 Object getWriteLockValue​(Object domainObject,
                                        Object primaryKey,
                                        org.eclipse.persistence.internal.sessions.AbstractSession session)
        INTERNAL: This method will return the optimistic lock value for the object.
        Specified by:
        getWriteLockValue in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        getWriteLockValue in class VersionLockingPolicy
      • getWriteLockUpdateExpression

        public Expression getWriteLockUpdateExpression​(ExpressionBuilder builder,
                                                       org.eclipse.persistence.internal.sessions.AbstractSession session)
        INTERNAL: Return an expression that updates the write lock
        Specified by:
        getWriteLockUpdateExpression in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        getWriteLockUpdateExpression in class VersionLockingPolicy
      • isNewerVersion

        public boolean isNewerVersion​(Object currentValue,
                                      Object domainObject,
                                      Object primaryKey,
                                      org.eclipse.persistence.internal.sessions.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 org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Overrides:
        isNewerVersion in class VersionLockingPolicy
      • isNewerVersion

        public boolean isNewerVersion​(org.eclipse.persistence.internal.sessions.AbstractRecord databaseRow,
                                      Object domainObject,
                                      Object primaryKey,
                                      org.eclipse.persistence.internal.sessions.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 org.eclipse.persistence.internal.descriptors.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.