Package org.eclipse.persistence.descriptors

Class VersionLockingPolicy

java.lang.Object
org.eclipse.persistence.descriptors.VersionLockingPolicy
All Implemented Interfaces:
Serializable, Cloneable, org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
Direct Known Subclasses:
TimestampLockingPolicy
public class VersionLockingPolicy extends Object implements org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy, Serializable

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

See Also:

  • Field Details

    • writeLockField

      protected org.eclipse.persistence.internal.helper.DatabaseField writeLockField

    • isCascaded

      protected boolean isCascaded

    • lockValueStored

      protected int lockValueStored

    • descriptor

      protected ClassDescriptor descriptor

    • cachedExpression

      protected transient Expression cachedExpression

    • IN_CACHE

      public static final int IN_CACHE
      See Also:

    • IN_OBJECT

      public static final int IN_OBJECT
      See Also:

    • lockMapping

      protected AbstractDirectMapping lockMapping
      PERF: Cache the lock mapping if mapped with a direct mapping.

    • lockOnChangeMode

      protected org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy.LockOnChange lockOnChangeMode

  • Constructor Details

    • VersionLockingPolicy

      public VersionLockingPolicy()
      PUBLIC: Create a new VersionLockingPolicy. Defaults to storing the lock value in the cache.

    • VersionLockingPolicy

      public VersionLockingPolicy(String fieldName)
      PUBLIC: Create a new VersionLockingPolicy. Defaults to storing the lock value in the cache.
      Parameters:
      fieldName - specifies the field name for the write lock field.

    • VersionLockingPolicy

      public VersionLockingPolicy(org.eclipse.persistence.internal.helper.DatabaseField field)
      PUBLIC: Create a new VersionLockingPolicy. Defaults to storing the lock value in the cache.
      Parameters:
      field - the write lock field.

  • Method Details

    • addLockFieldsToUpdateRow

      public void addLockFieldsToUpdateRow(org.eclipse.persistence.internal.sessions.AbstractRecord databaseRow, org.eclipse.persistence.internal.sessions.AbstractSession session)
      INTERNAL: Add update fields for template row. These are any unmapped fields required to write in an update.
      Specified by:
      addLockFieldsToUpdateRow in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • addLockValuesToTranslationRow

      public void addLockValuesToTranslationRow(ObjectLevelModifyQuery query)
      INTERNAL: This method adds the lock value to the translation row of the passed in query. depending on the storage flag, the value is either retrieved from the cache of the object.
      Specified by:
      addLockValuesToTranslationRow in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • buildDeleteExpression

      public Expression buildDeleteExpression(org.eclipse.persistence.internal.helper.DatabaseTable table, Expression mainExpression, org.eclipse.persistence.internal.sessions.AbstractRecord row)
      INTERNAL: When given an expression, this method will return a new expression with the optimistic locking values included. The values are taken from the passed in database row. This expression will be used in a delete call.
      Specified by:
      buildDeleteExpression in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • buildExpression

      protected Expression buildExpression()
      INTERNAL: Returns an expression that will be used for both the update and delete where clause

    • buildUpdateExpression

      public Expression buildUpdateExpression(org.eclipse.persistence.internal.helper.DatabaseTable table, Expression mainExpression, org.eclipse.persistence.internal.sessions.AbstractRecord row, org.eclipse.persistence.internal.sessions.AbstractRecord row2)
      INTERNAL: When given an expression, this method will return a new expression with the optimistic locking values included. The values are taken from the passed in database row. This expression will be used in an update call.
      Specified by:
      buildUpdateExpression in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • clone

      public Object clone()
      INTERNAL: Clone the policy
      Specified by:
      clone in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
      Overrides:
      clone in class Object

    • supportsWriteLockValuesComparison

      public boolean supportsWriteLockValuesComparison()
      INTERNAL: Indicates that compareWriteLockValues method is supported by the policy.
      Specified by:
      supportsWriteLockValuesComparison in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • compareWriteLockValues

      public int compareWriteLockValues(Object value1, Object value2)
      INTERNAL: This method compares two writeLockValues. The writeLockValues should be non-null and of type Number. 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

    • getDefaultLockingFieldType

      protected Class getDefaultLockingFieldType()
      INTERNAL: Return the default version locking filed java type, default is BigDecimal

    • 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

    • getDescriptor

      protected ClassDescriptor getDescriptor()
      INTERNAL:

    • getInitialWriteValue

      protected Object getInitialWriteValue(org.eclipse.persistence.internal.sessions.AbstractSession session)
      INTERNAL: returns the initial locking value

    • getLockOnChangeMode

      public org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy.LockOnChange getLockOnChangeMode()
      ADVANCED: returns the LockOnChange mode for this policy. This mode specifies if a Optimistic Write lock should be enforced on this entity when a set of mappings are changed. Unfortunately this locking policy can not enforce an optimistic write lock unless a FK or DTF field has changed so this type returns LockOnChange.NONE
      Specified by:
      getLockOnChangeMode in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • getNewLockValue

      public Object getNewLockValue(ModifyQuery query)
      INTERNAL: This method gets the write lock value from either the cache or the object stored in the query. It then returns the new incremented value.

    • getUnmappedFields

      protected Vector getUnmappedFields()
      INTERNAL: This method returns any of the fields that are not mapped in the object. In the case of the value being stored in the cache, a vector with one value is returned. In the case of being stored in the object, an empty vector is returned.

    • 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

    • getVersionDifference

      public int getVersionDifference(Object currentValue, Object domainObject, Object primaryKeys, org.eclipse.persistence.internal.sessions.AbstractSession session)
      PUBLIC: Return the number of versions different between these objects.
      Specified by:
      getVersionDifference in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
      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

    • getWriteLockField

      public org.eclipse.persistence.internal.helper.DatabaseField getWriteLockField()
      INTERNAL: Return the write lock field.
      Specified by:
      getWriteLockField in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • getWriteLockFieldName

      public String getWriteLockFieldName()
      PUBLIC: Return the field name of the field that stores the write lock value.

    • getWriteLockUpdateExpression

      public Expression getWriteLockUpdateExpression(ExpressionBuilder builder, org.eclipse.persistence.internal.sessions.AbstractSession session)
      INTERNAL: Retrun an expression that updates the write lock
      Specified by:
      getWriteLockUpdateExpression in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • 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

    • incrementWriteLockValue

      protected Number incrementWriteLockValue(Number numberValue)
      INTERNAL: Adds 1 to the value passed in.

    • initialize

      public void initialize(org.eclipse.persistence.internal.sessions.AbstractSession session)
      INTERNAL: It is responsible for initializing the policy;
      Specified by:
      initialize in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • initializeProperties

      public void initializeProperties()
      INTERNAL: It is responsible for initializing the policy properties;
      Specified by:
      initializeProperties in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • isCascaded

      public boolean isCascaded()
      PUBLIC: Return true if the policy uses cascade locking.
      Specified by:
      isCascaded in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • 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

    • 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

    • isNewerVersion

      public boolean isNewerVersion(Object firstLockFieldValue, Object secondWriteLockFieldValue)
      INTERNAL: Compares two values. Will return true if the firstLockFieldValue is newer than the secondWriteLockFieldValue.

    • isStoredInCache

      public boolean isStoredInCache()
      PUBLIC: Return true if the lock value is stored in the cache.
      Specified by:
      isStoredInCache in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • isStoredInObject

      public boolean isStoredInObject()
      PUBLIC: Return true if the lock value is stored in the object.

    • lockValueFromObject

      protected Object lockValueFromObject(Object domainObject)
      INTERNAL: Retrieves the lock value from the object.

    • getVersionMapping

      public AbstractDirectMapping getVersionMapping()
      INTERNAL: Returns the mapping that will be used to access the version value from an object.

    • mergeIntoParentCache

      public void mergeIntoParentCache(org.eclipse.persistence.internal.sessions.UnitOfWorkImpl uow, Object primaryKey, Object object)
      INTERNAL: Only applicable when the value is stored in the cache. Will merge with the parent unit of work.
      Specified by:
      mergeIntoParentCache in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • mergeIntoParentCache

      public void mergeIntoParentCache(org.eclipse.persistence.internal.identitymaps.CacheKey unitOfWorkCacheKey, org.eclipse.persistence.internal.identitymaps.CacheKey parentSessionCacheKey)
      INTERNAL: This method should merge changes from the parent into the child. #see this method in VersionLockingPolicy
      Specified by:
      mergeIntoParentCache in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • setDescriptor

      public void setDescriptor(ClassDescriptor descriptor)
      INTERNAL:
      Specified by:
      setDescriptor in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • setIsStoredInCache

      public void setIsStoredInCache(boolean isStoredInCache)
      PUBLIC: Set whether to store the lock in the cache or in the object.
      Parameters:
      isStoredInCache - set this to true if you would like to store lock in the cache and set it to false if you would like to store it in the object.

    • setIsCascaded

      public void setIsCascaded(boolean isCascaded)
      PUBLIC: Set whether to use cascade locking on the policy.
      Parameters:
      isCascaded - set this to true if you would like cascade the locking and set it to false if you would like no cascade locking.

    • setupWriteFieldsForInsert

      public void setupWriteFieldsForInsert(ObjectLevelModifyQuery query)
      INTERNAL: This method must be included in any locking policy. Put the initial writelock value into the modifyRow.
      Specified by:
      setupWriteFieldsForInsert in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • updateWriteLockValueForWrite

      protected void updateWriteLockValueForWrite(ObjectLevelModifyQuery query, Object lockValue)
      INTERNAL: Update the row, object and change set with the version value. This handles the version being mapped in nested aggregates, writable or read-only.

    • shouldUpdateVersionOnOwnedMappingChange

      public boolean shouldUpdateVersionOnOwnedMappingChange()
      INTERNAL: Returns true if the policy has been set to set an optimistic read lock when a owning mapping changes.
      Specified by:
      shouldUpdateVersionOnOwnedMappingChange in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • shouldUpdateVersionOnMappingChange

      public boolean shouldUpdateVersionOnMappingChange()
      INTERNAL: Returns true if the policy has been set to set an optimistic read lock when any mapping changes.
      Specified by:
      shouldUpdateVersionOnMappingChange in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • updateObjectWithWriteValue

      public void updateObjectWithWriteValue(ObjectLevelModifyQuery query, Object lockValue)

    • setLockOnChangeMode

      public void setLockOnChangeMode(org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy.LockOnChange lockOnChangeMode)
      ADVANCED: Sets the LockOnChange mode for this policy. This mode specifies if a Optimistic Write lock should be enforced on this entity when set of mappings are changed.
      Specified by:
      setLockOnChangeMode in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • setWriteLockField

      public void setWriteLockField(org.eclipse.persistence.internal.helper.DatabaseField writeLockField)
      ADVANCED: Set the write lock field. This can be used for advanced field types, such as XML nodes, or to set the field type.

    • setWriteLockFieldName

      public void setWriteLockFieldName(String writeLockFieldName)
      PUBLIC: Set the write lock field name.
      Parameters:
      writeLockFieldName - the name of the field to lock against.

    • storeInCache

      public void storeInCache()
      PUBLIC: Configure the version lock value to be stored in the cache. This allows for the object not to require to store its version value as an attribute. Note: if using a stateless model where the object can be passed to a client and then later updated in a different transaction context, then the version lock value should not be stored in the cache, but in the object to ensure it is the correct value for that object. This is the default.

    • storeInObject

      public void storeInObject()
      PUBLIC: Configure the version lock value to be stored in the object. The object must define a mapping and an attribute to store the version value. Note: the value will be updated internally by EclipseLink and should not be updated by the application.

    • updateRowAndObjectForUpdate

      public void updateRowAndObjectForUpdate(ObjectLevelModifyQuery query, Object domainObject)
      INTERNAL: This method updates the modify row, and the domain object with the new lock value.
      Specified by:
      updateRowAndObjectForUpdate in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • writeLockValueIntoRow

      public void writeLockValueIntoRow(ObjectLevelModifyQuery query, Object domainObject)
      INTERNAL: This method updates the modify row with the old lock value.

    • validateDelete

      public void validateDelete(int rowCount, Object object, DeleteObjectQuery query)
      INTERNAL: Check the row count for lock failure.
      Specified by:
      validateDelete in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy

    • validateUpdate

      public void validateUpdate(int rowCount, Object object, WriteObjectQuery query)
      INTERNAL: Check the row count for lock failure.
      Specified by:
      validateUpdate in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy