Class SelectedFieldsLockingPolicy

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

    public class SelectedFieldsLockingPolicy
    extends FieldsLockingPolicy

    Purpose: An implementation of the OptimisticLockingPolicy interface. This policy compares selected fields in the WHERE clause when doing an update or a delete. If any field has been changed, an optimistic locking exception will be thrown. Note that the fields specified must be mapped and not be primary keys.

    NOTE: This policy can only be used inside a unit of work.

    See Also:
    Serialized Form
    Since:
    TopLink 2.5
    • Field Detail

      • lockFieldsByTable

        protected Map<org.eclipse.persistence.internal.helper.DatabaseTable,​List<org.eclipse.persistence.internal.helper.DatabaseField>> lockFieldsByTable
      • lockFields

        protected List<org.eclipse.persistence.internal.helper.DatabaseField> lockFields
    • Constructor Detail

      • SelectedFieldsLockingPolicy

        public SelectedFieldsLockingPolicy()
        PUBLIC: Create a new selected fields locking policy. A field locking policy is based on locking on the specified fields by comparing with their previous values to detect field-level collisions. Note: the unit of work must be used for all updates when using field locking.
    • Method Detail

      • addLockFieldName

        public void addLockFieldName​(String fieldName)
        PUBLIC: Add a field name to lock on. All fields in this list will be compared when updating if the value of any of the fields does not match the value in memory, an OptimisticLockException will be thrown. Note: An Automatic update will not be done on this field, only a comparison occurs.
      • addLockValuesToTranslationRow

        public void addLockValuesToTranslationRow​(ObjectLevelModifyQuery query)
                                           throws DatabaseException
        INTERNAL: Values to be included in the locking mechanism are added to the translation row. For changed fields the normal build row is ok as only changed fields matter.
        Specified by:
        addLockValuesToTranslationRow in interface org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy
        Specified by:
        addLockValuesToTranslationRow in class FieldsLockingPolicy
        Throws:
        DatabaseException
      • getFieldsToCompare

        protected List<org.eclipse.persistence.internal.helper.DatabaseField> getFieldsToCompare​(org.eclipse.persistence.internal.helper.DatabaseTable table,
                                                                                                 org.eclipse.persistence.internal.sessions.AbstractRecord transRow,
                                                                                                 org.eclipse.persistence.internal.sessions.AbstractRecord modifyRow)
        INTERNAL: returns the lock fields to compare based on the passed in table.
        Specified by:
        getFieldsToCompare in class FieldsLockingPolicy
      • getLockFields

        public List<org.eclipse.persistence.internal.helper.DatabaseField> getLockFields()
        INTERNAL: Returns the lock fields
      • getLockFields

        protected List<org.eclipse.persistence.internal.helper.DatabaseField> getLockFields​(org.eclipse.persistence.internal.helper.DatabaseTable table)
        INTERNAL: returns the lock fields based on the passed in table
      • getLockFieldsByTable

        protected Map<org.eclipse.persistence.internal.helper.DatabaseTable,​List<org.eclipse.persistence.internal.helper.DatabaseField>> getLockFieldsByTable()
        INTERNAL: returns the lock fields
      • 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
        Overrides:
        initialize in class FieldsLockingPolicy
      • setLockFieldNames

        public void setLockFieldNames​(List<String> lockFieldNames)
        PUBLIC: Set the field names to lock on. All fields in this list will be compared when Updating. If the value of any of the fields does not match the value in memory, an OptimisticLockException will be thrown. Note: An Automatic update will not be done on this field, only a comparison occurs.
      • setLockFields

        protected void setLockFields​(List<org.eclipse.persistence.internal.helper.DatabaseField> lockFields)
        INTERNAL: Sets the lock fields
      • setLockFieldsByTable

        protected void setLockFieldsByTable​(Map<org.eclipse.persistence.internal.helper.DatabaseTable,​List<org.eclipse.persistence.internal.helper.DatabaseField>> lockFieldsByTable)
        INTERNAL: Used to set the field names to be used in this policy.