Spring数据 - 域对象继承和泛型方法

Question

I have some domain objects:

@Entity
public class Log {

}

@Entity
public class LogLetter extends Log {

}

@Entity
public class LogAction extends Log {

}

and I want to have only one repository which allows me to get Log's childs.

Can I do teoretically something like this?

public interface LogRepository extends CrudRepository<Log, Long> {

    @Query("select from ?1)
    public <T> List<T> getLog(Class<T> clazz);

}

and call this method:

List<LogLetter> logLetters = getLog(LogLetters.class);

Exist any other approaches to do what I described?

Answer 1

I don't think it's possible out of the box (especially given the fact that you cannot use parameters in from ), but you can implement it as a custom method (see 1.4. Custom implementations ):

public <T> List<T> getLog(Class<T> clazz) {
    return em.createQuery("from " + clazz.getSimpleName()).getResultList();
}

Answer 2

You could also implement it using #{#entityName} :

@Query("SELECT o FROM #{#entityName} o where o.attribute1=:attribute1")
Page<T> findByAttribute1Custom(@Param("attribute1") String attribute1, Pageable pageable);