How to obtain Class from JPA entity name?

Question

Is there a way to find out the

  java.lang.Class 

that is the one having

@Entity(name = "X")?

In other words use the Entity Name to get the classname of the Entity, of course at runtime :)

Answer 1

All registered @Entitys are available by MetaModel#getEntities(). It returns a List<EntityType<?>> whereby the EntityType has a getName() method representing the @Entity(name) and a getJavaType() representing the associated @Entity class. The MetaModel instance is in turn available by EntityManager#getMetaModel().

In other words, here's the approach in flavor of an utility method:

public static Class<?> getEntityClass(EntityManager entityManager, String entityName) {
    for (EntityType<?> entity : entityManager.getMetamodel().getEntities()) {
        if (entityName.equals(entity.getName())) {
            return entity.getJavaType();
        }
    }

    return null;
}