How to use

getValueGenerator

method

in

org.jboss.errai.jpa.client.local.ErraiSingularAttribute

/**
 * Generates a new ID value for the given entity instance that is guaranteed
 * to be unique <i>on this client</i>. If the entity instance with this ID is
 * ever synchronized to the server, this client-local ID will be replaced by a
 * permanent server-generated ID.
 * <p>
 * This method only works for attributes that are configured as
 * {@code @GeneratedValue}s. The GenerationType has no effect locally, but of
 * course it will come into play on the server side when and if the entity is
 * synchronized to the server.
 *
 * @param entityInstance
 *          the entity instance to receive the generated ID. This attribute of
 *          that entity instance will be set to the newly generated ID value.
 * @return the generated ID value, which has already been set on the entity
 *         instance.
 */
private <X, T> T generateAndSetLocalId(final X entityInstance, final ErraiSingularAttribute<X, T> attr) {
 final T nextId = attr.getValueGenerator().next(this);
 attr.set(entityInstance, nextId);
 return nextId;
}

ErraiIdentifiableType<E> entityType = desiredStateEm.getMetamodel().entity(entityClass);
ErraiSingularAttribute<? super E, Object> idAttr = entityType.getId(Object.class);
ErraiIdGenerator<Object> idGenerator = idAttr.getValueGenerator();
if (idGenerator != null && idGenerator.hasNext(desiredStateEm)) {
 Object newLocalId = idGenerator.next(desiredStateEm);