443 words

javax.persistence.PessimisticLockScope - JPA enum

javax.persistence
Enum PessimisticLockScope

java.lang.Object
    java.lang.Enum<javax.persistence.PessimisticLockScope>
        javax.persistence.PessimisticLockScope
Implemented Interfaces:
Serializable, Comparable<PessimisticLockScope>
Defines the values of the javax.persistence.lock.scope property for pessimistic locking. This property may be passed as an argument to the methods of the EntityManager, Query, and TypedQuery interfaces that allow lock modes to be specified or used with the NamedQuery annotation.
Since:
JPA 2.0
In addition to the behavior for PessimisticLockScope.NORMAL, element collections and relationships owned by the entity that are contained in join tables will be locked if the javax.persistence.lock.scope property is specified with a value of PessimisticLockScope.EXTENDED.
In addition to the behavior for PessimisticLockScope.NORMAL, element collections and relationships owned by the entity that are contained in join tables will be locked if the javax.persistence.lock.scope property is specified with a value of PessimisticLockScope.EXTENDED. The state of entities referenced by such relationships will not be locked (unless those entities are explicitly locked). Locking such a relationship or element collection generally locks only the rows in the join table or collection table for that relationship or collection. This means that phantoms will be possible.
Since:
JPA 2.0
This value defines the default behavior for pessimistic locking.
This value defines the default behavior for pessimistic locking.

The persistence provider must lock the database row(s) that correspond to the non-collection-valued persistent state of that instance. If a joined inheritance strategy is used, or if the entity is otherwise mapped to a secondary table, this entails locking the row(s) for the entity instance in the additional table(s). Entity relationships for which the locked entity contains the foreign key will also be locked, but not the state of the referenced entities (unless those entities are explicitly locked). Element collections and relationships for which the entity does not contain the foreign key (such as relationships that are mapped to join tables or unidirectional one-to-many relationships for which the target entity contains the foreign key) will not be locked by default.

Since:
JPA 2.0

Returns the enum constant of this type with the specified name.

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type.

Parameters:
name - the name of the enum constant to be returned.
Returns:
the enum constant with the specified name
Throws:
java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
java.lang.NullPointerException - if the argument is null

Returns an array containing the constants of this enum type.

Returns an array containing the constants of this enum type.

This method may be used to iterate over the constants as follows:

for (PessimisticLockScope c : PessimisticLockScope.values())
    System.out.println(c)
Returns:
an array containing the constants of this enum type, in the order they are declared


This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
Object DB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.