How (or can) I specify programmatically which validation group OpenJPA should validate against during a persist or merge operation? Is this option only available via persistence.xml?
I'm drawing a blank.
Thanks.
The groups are configured per entity manager factory. If you obtain your entity manager factory programmatically via Persistence#createEntityManagerFactory() you can pass the groups to be validated during lifecycle validation using the properties javax.persistence.validation.group.{pre-persist|pre-update|pre-remove} but there is no (standardized) way for specifying the groups on a per-operation basis.
Yes, configuration is only via persistence.xml. I guess it would be open for JPA implementations to provide implementation specific ways, but that's not standardized. I am not sure whether OpenJPa offers such a provider specific option, but I don't think so.
Related
Spring Data allows you to declare methods like findByLastname() in your repository interface and it generates the queries from the method name automatically for you.
Is it possible to somehow have these automatically-generated queries also accept a Specification, so that additional restrictions can be made on the data before it's returned?
That way, I could for example call findByLastname("Ted", isGovernmentWorker()), which would find all users that have the last name Ted AND who satisfy the isGovernmentWorker() specification.
I need this because I'd like the automated query creation provided by Spring Data and because I still need to be able to apply arbitrary specifications at runtime.
There is no such feature. Specifications can only be applied on JpaSpecificationExecutor operations.
Update
The data access operations are generated by a proxy. Thus if we want to group the operations (as in findByName + Criteria) in a single SELECT call, the proxy must understand and support this kind of usage; which it does not.
The intended usage, when employing Specification API would look like this for your case:
findAll(Specifications.where(hasLastName("Ted")).and(isGovernmentWorker())
Spring data allows you to implement custom repository and use Specifications or QueryDSL.
Please see this article.
So at the end you will have one YourCustomerRepository and appropriate YourRepositoryImpl implementation, where you will put your findByLastname("Ted", isGovernmentWorker()) method.
And then YourRepository should extend YourCustomerRepository interface.
I'd like to know if it's mandatory to use DataAnnotations for breezejs ef metadata provider to properly get all configurations for each entity? Alternatively, can one avoid the use of any conventions or data annotations and instead configure a mapping class for each entity with explicit mappings and configurations?
You have several options:
1) You can define the metadata yourself on either the client or server, instead of having it generated from EF metadata. See the Breeze Metadata discussion here
2) You can define this same metadata on the client. See the MetadataStore addEntityType method.
3) Along with either of the two options above, you can 'reinterpret' any json results returned from any web service call with the JsonResultsAdapter. We will have an example of this out within the next week or so. By default, this is done for you, but you can intercept the process.
4) Hybrid use, where some entities are defined via metadata from the server and some from client side metadata are also possible. Similarly, you can choose to implement a JsonResultsAdapter for just selected queries and use the default for the rest.
Hope this helps.
Found an article in springsource which describes how to manipulate the schema name at runtime.
http://forum.springsource.org/showthread.php?18715-changing-hibernate-schemas-at-runtime
We're using pure jpa however where were using a LocalContainerEntityManagerFactory and don't have access to Session or Conofiguration instances.
Can anyone provide insight on how to access the metadata at runtime (via the entitymanager) to allow modifying the schema?
Thanks
Changing meta-data at runtime is JPA provider specific. JPA allows you to pass a Map of provider specific properties when creating an EntityManagerFactory or EntityManager. JPA also allows you to unwrap() an EntityManager to a provider specific implementation.
If you are using EclipseLink you can set the schema using the setTableQualifier() API on the Session's login.
You can't using standard JPA (which is your requirement going by your question); it doesn't allow you to dynamically define metadata, only view (a limited amount of) specified metadata via its metamodel API. You'd have to delve into implementation specifics to get further, but then your portability goes down the toilet at that point, which isn't a good thing.
JDO, on the other hand, does allow you to dynamically define metadata (and hence schema) using standardised APIs.
I am using Spring Data JPA in an application in which all entity objects need auditing. I know that I can have each either implement Auditable or extend AbstractAuditable, but my problem is coming with the overall auditing implementation.
The example on the Spring Data JPA reference pages seems to indicate that you need an AuditableAware bean for each entity. Is there any way to avoid this extra code and handle it in one place or through one configuration?
The generic parameter of AuditorAware is not the entity you want to capture the auditing information for but rather the creating/modifying one. So it will typically be the user currently logged in or the like.
I have an entity bean that will represent an expected result over multiple databases/datasources and can also be different queries executed, but same result always comming back. So the bean is re-used over different datasources that should be able to be dynamicly selected.
Is it possible with JPA to select during runtime the data source to be used to execute a query, and return the same type of entity bean?
Also, does my ejb/application need to define the datasources that will be used? Or can I always specify via jndi what datasource to use? Modifying the descriptor's and re-deploying an application everytime a new datasource is created is not an option.
Sorry if the question does not make 100% sense, rather difficult to get the idea through.
Is it possible with JPA to select during runtime the data source to be used to execute a query, and return the same type of entity bean?
You can't change the datasource of a persistence unit at runtime. However, you can configure several persistence unit and use one or another EntityManagerFactory. Maybe JPA is not the right tool for your use case.
Modifying the descriptor's and re-deploying an application everytime a new datasource is created is not an option.
And how will the application be aware of the "available datasources"?
You can change the JPA datasource at runtime, but the approach is tricky (introspection, JPA implementation specific, ...).
I've implemented my own implementation of javax.persistence.spi.PersistenceProviderwhich override the org.hibernate.ejb.HibernatePersistence and sets the datasource in both the Map and PersistenceUnitInfo of the PersistenceProvider just before creating the EntityManagerFactory. This way, my EntityManagerFactory has a datasource which has been configured at runtime. I keep my EntityManagerFactory until the application is undeployed.
You could use the same be approach and create N different EntityManagerFactory, each with its specific datasource. However keep in mind that each ÈntityManagerFactory uses a lot of memory.