public interface HibernateIntegration

Integration with Hibernate

Smart GWT integrates with Hibernate via DataSource descriptors (.ds.xml files) with serverType="hibernate". A JPA entity bean class is required, specified via beanClassName or schemaBean (which doubles as beanClassName when the latter is not set). Smart GWT can automatically derive DataSource fields from the bean using DataSource.autoDeriveSchema — in this case the .ds.xml only needs to declare overrides for fields where the derived defaults are insufficient.

If you do not need Hibernate-specific features (named queries, Hibernate relations, Spring transaction integration), consider using serverType="sql" (SQLDataSource) instead. SQLDataSource requires no entity beans and provides equivalent CRUD, filtering, paging and export capabilities with simpler configuration.

Note that the Admin Console's "Import DataSources" section can be used to import test data into serverType:"hibernate" DataSources in the same manner as SQLDataSources.

HibernateDataSource supports operations with composite primary keys. Setting data source level property idClassName to fully qualified class name indicates, that entity uses composite primary key.

Beans and the DSRequest / DSResponse

In case of "pre-existing beans" approach, see HbBeans for the information how incoming DSRequest data is used and what to expect in DSResponse.

Hibernate relations

For Hibernate integration where Java beans have been explicitly declared, HibernateDataSource supports automatic handling of Hibernate relations that don't declare a concrete field to hold ID values - see JpaHibernateRelations.

Hibernate Configuration

You can provide Hibernate configuration to the Smart GWT server in three ways:

You can place a traditional hibernate.cfg.xml file somewhere on the classpath
You can have Smart GWT look up a Hibernate Configuration to use. This works in the same way as a ServerObject, and in fact makes use of the ServerObject code, though note that lookupStyle "attribute" is not supported. To look up a configuration, add ServerObject-compliant properties to your server.properties file, prefixed with hibernate.config. For example:
```
         hibernate.config.lookupStyle: spring
         hibernate.config.bean: mySessionFactory
  
```
You can provide a Hibernate configuration at the level of individual DataSources, by specifying a configBean on the dataSource (this is only applicable if you are using Spring; see below)

If you choose to have Smart GWT lookup the Hibernate configuration, and you specify a lookupStyle of "spring", Smart GWT will make use of a Hibernate SessionFactory configured by Spring. It is possible to set up multiple Hibernate configurations in Spring, and to map individual DataSources to different configurations by making use of the dataSource.configBean property mentioned above. Please note the following caveats:

DataSource-level Hibernate configuration is intended for unusual cases, such as when the physical data store for one DataSource is actually a different database. Hibernate relations between entities with different configurations do not work
A Spring-managed SessionFactory does not support adding entity mappings at runtime. All entity beans must be pre-registered in the Spring configuration (via annotated class scanning, .cfg.xml mappings referenced by the configLocation property, or Spring bean properties)

Inbound DSRequest data will use numeric field types from your bean

For fields with numeric types, the record data in DSRequests will automatically be converted to the type of the target field, before the request is received in a DMI. For details, see DsRequestBeanTypes.

Manual Hibernate Integration

In some cases you may not be able to immediately use the built-in HibernateDataSource - in this case take a look at manual Hibernate integration.