Custom Shortcut Annotations I know, that I could create a custom annotation, but that seems unnatural. No, this is exactly the use case for a Custom Annotation. Here’s a quote from Custom Shortcut Annotations in the Spring Reference: If you find you are repeatedly using the same attributes with @Transactional on many different methods, then … Read more
To sum everything (L2 cache and query cache) up: The first thing to do is to add cache provider (I recommend using EhCache) to your classpath. Hibernate < 5.3 Add the hibernate-ehcache dependency. This library contains EhCache 2 which is now discontinued. <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-ehcache</artifactId> <version>your_hibernate_version</version> </dependency> Hibernate >=5.3 In newer versions of Hibernate caches … Read more
Maybe the following extract from the Chapter 23 – Using the Criteria API to Create Queries of the Java EE 6 tutorial will throw some light (actually, I suggest reading the whole Chapter 23): Querying Relationships Using Joins For queries that navigate to related entity classes, the query must define a join to the related … Read more
Specification says that derived entity should be the owning side of the relationship: 2.4.1 Primary Keys Corresponding to Derived Identities The identity of an entity may be derived from the identity of another entity (the “parent” entity) when the former entity (the “dependent” entity) is the owner of a many-to-one or one-to-one relationship to the … Read more
If I understand well, you want to Join ScheduleRequest with User and apply the in clause to the userName property of the entity User. I’d need to work a bit on this schema. But you can try with this trick, that is much more readable than the code you posted, and avoids the Join part … Read more
A query of type MyEntity is going to return MyEntity. You want a query for a Long. CriteriaBuilder qb = entityManager.getCriteriaBuilder(); CriteriaQuery<Long> cq = qb.createQuery(Long.class); cq.select(qb.count(cq.from(MyEntity.class))); cq.where(/*your stuff*/); return entityManager.createQuery(cq).getSingleResult(); Obviously you will want to build up your expression with whatever restrictions and groupings etc you skipped in the example.
according to the book “Pro EJB 3 Java Persistence API” Constructor Expressions A more powerful form of SELECT clause involving multiple expressions is the constructor expression, which specifies that the results of the query are to be stored using a user-specified object type. Consider the following query: SELECT NEW example.EmployeeDetails(e.name, e.salary, e.department.name) FROM Employee e … Read more
You can use a plugin like Eclipse Dali to do the trick for you. You can refer to the documentation, section 3.11 Generating Entities from Tables. I do not know of any specific vendor independent tool to do this, though.
As @Korgen mentioned in comments hibernate-validator-5.x.x isn’t compatible with validation-api-1.0.x. This is because of moving to new specification JSR-303 -> JSR-349. There are two ways to solve this issue: 1. Downgrade hibernate validator version (which is implements JSR-303): <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>4.3.1.Final</version> </dependency> 2. If you don’t want to move back from hibernate validator 5 … Read more
By default the access type is defined by the place where you put your identifier annotation (@Id). If you put it on the field – it will be AccessType.FIELD, if you put it on the getter – it will be AccessType.PROPERTY. Sometimes you might want to annotate not fields but properties (e.g. because you want … Read more