Criteria API

Building Queries in Code

The Criteria API builds queries with Java objects instead of strings. It is useful when filters change at runtime, such as in a search form where users fill in only some fields.

The old Hibernate-specific session.createCriteria() was removed in Hibernate 6. The current option is the Jakarta Persistence Criteria API shown here.

CriteriaBuilder cb = session.getCriteriaBuilder();
CriteriaQuery<Student> query = cb.createQuery(Student.class);
Root<Student> root = query.from(Student.class);

query.select(root)
     .where(cb.equal(root.get("status"), Status.ACTIVE))
     .orderBy(cb.asc(root.get("name")));

List<Student> result = session.createQuery(query).getResultList();

Code Explanation:

• CriteriaBuilder creates queries and conditions.
• Root represents the entity in the from clause.
• root.get("status") refers to a field by name, and a wrong name fails only at runtime.
• where() and orderBy() add filtering and sorting.
• session.createQuery(query) turns the criteria object into an executable query.

For dynamic filters, collect conditions in a list of Predicate objects and add only those that apply. To catch field name mistakes at compile time, generate the static metamodel using the hibernate-processor annotation processor.