Examples with ValueHolderInterface org.eclipse.persistence.indirection.ValueHolderInterface used on opensource projects

Example 1 with ValueHolderInterface

use of org.eclipse.persistence.indirection.ValueHolderInterface in project cuba by cuba-platform.

the class PersistenceTools method getReferenceId.

/**
 * Returns an ID of directly referenced entity without loading it from DB.
 * <p>
 * If the view does not contain the reference and {@link View#loadPartialEntities()} is true,
 * the returned {@link RefId} will have {@link RefId#isLoaded()} = false.
 *
 * <p>Usage example:
 * <pre>
 *   PersistenceTools.RefId refId = persistenceTools.getReferenceId(doc, "currency");
 *   if (refId.isLoaded()) {
 *       String currencyCode = (String) refId.getValue();
 *   }
 * </pre>
 *
 * @param entity   entity instance in managed state
 * @param property name of reference property
 * @return {@link RefId} instance which contains the referenced entity ID
 * @throws IllegalArgumentException if the specified property is not a reference
 * @throws IllegalStateException    if the entity is not in Managed state
 * @throws RuntimeException         if anything goes wrong when retrieving the ID
 */
public RefId getReferenceId(BaseGenericIdEntity entity, String property) {
    MetaClass metaClass = metadata.getClassNN(entity.getClass());
    MetaProperty metaProperty = metaClass.getPropertyNN(property);
    if (!metaProperty.getRange().isClass() || metaProperty.getRange().getCardinality().isMany())
        throw new IllegalArgumentException("Property is not a reference");
    if (!entityStates.isManaged(entity))
        throw new IllegalStateException("Entity must be in managed state");
    String[] inaccessibleAttributes = BaseEntityInternalAccess.getInaccessibleAttributes(entity);
    if (inaccessibleAttributes != null) {
        for (String inaccessibleAttr : inaccessibleAttributes) {
            if (inaccessibleAttr.equals(property))
                return RefId.createNotLoaded(property);
        }
    }
    if (entity instanceof FetchGroupTracker) {
        FetchGroup fetchGroup = ((FetchGroupTracker) entity)._persistence_getFetchGroup();
        if (fetchGroup != null) {
            if (!fetchGroup.containsAttributeInternal(property))
                return RefId.createNotLoaded(property);
            else {
                Entity refEntity = (Entity) entity.getValue(property);
                return RefId.create(property, refEntity == null ? null : refEntity.getId());
            }
        }
    }
    try {
        Class<?> declaringClass = metaProperty.getDeclaringClass();
        if (declaringClass == null) {
            throw new RuntimeException("Property does not belong to persistent class");
        }
        Method vhMethod = declaringClass.getDeclaredMethod(String.format("_persistence_get_%s_vh", property));
        vhMethod.setAccessible(true);
        ValueHolderInterface vh = (ValueHolderInterface) vhMethod.invoke(entity);
        if (vh instanceof DatabaseValueHolder) {
            AbstractRecord row = ((DatabaseValueHolder) vh).getRow();
            if (row != null) {
                Session session = persistence.getEntityManager().getDelegate().unwrap(Session.class);
                ClassDescriptor descriptor = session.getDescriptor(entity);
                DatabaseMapping mapping = descriptor.getMappingForAttributeName(property);
                Vector<DatabaseField> fields = mapping.getFields();
                if (fields.size() != 1) {
                    throw new IllegalStateException("Invalid number of columns in mapping: " + fields);
                }
                Object value = row.get(fields.get(0));
                if (value != null) {
                    ClassDescriptor refDescriptor = mapping.getReferenceDescriptor();
                    DatabaseMapping refMapping = refDescriptor.getMappingForAttributeName(metadata.getTools().getPrimaryKeyName(metaClass));
                    if (refMapping instanceof AbstractColumnMapping) {
                        Converter converter = ((AbstractColumnMapping) refMapping).getConverter();
                        if (converter != null) {
                            return RefId.create(property, converter.convertDataValueToObjectValue(value, session));
                        }
                    }
                }
                return RefId.create(property, value);
            } else {
                return RefId.create(property, null);
            }
        }
        return RefId.createNotLoaded(property);
    } catch (Exception e) {
        throw new RuntimeException(String.format("Error retrieving reference ID from %s.%s", entity.getClass().getSimpleName(), property), e);
    }
}