PersonBaseDaoImpl.java

package projects.mvc.first.repositorys;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import projects.mvc.first.entitys.Person;
import projects.mvc.first.exceptions.db.NoteNotFoundException;

import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import java.util.List;

@Repository(value = "personBaseDaoImpl")
public class PersonBaseDaoImpl implements PersonBaseDAO {
    /* Что будет лучше: делать свою реализацию или унаследовать
    PersonBaseDAO от CrudRepository, где она сама сгенерируется? */

    private static final Logger log = Logger.getLogger(SomeKindPersonBase.class);

    @Autowired
    EntityManager entityManager;

    @Override
    public Person getPerson(Integer id) throws NoteNotFoundException {
        Person person = entityManager.find(Person.class, id);
        if(person != null) {
            log.info("Successfully found note with id=" + id);
            return person;
        } else {
            throw new NoteNotFoundException("Not found note with id=" + id);
        }
    }

    @Override
    public List<Person> getAllPeople() {
        CriteriaBuilder cb = entityManager.getCriteriaBuilder();
        CriteriaQuery<Person> personCriteria = cb.createQuery(Person.class);
        Root<Person> personRoot = personCriteria.from(Person.class);
        personCriteria.select(personRoot);
        return entityManager.createQuery(personCriteria).getResultList();
    }

    @Override
    public void addPerson(Person person) {
        EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();
        entityManager.persist(person);
        transaction.commit();
    }

    @Override
    public void deletePerson(Integer id) throws NoteNotFoundException {
        EntityTransaction transaction = entityManager.getTransaction();
        Person person = entityManager.find(Person.class, id);
        if(person != null) {
            transaction.begin();
            entityManager.remove(person);
            transaction.commit();
            log.info("Successfully delete note with id=" + id);
        } else {
            throw new NoteNotFoundException("Delete operation failed. A note with id=" + id + " not exists");
        }
    }

    @Override

    public void updatePerson(Person person) throws NoteNotFoundException {
        EntityTransaction transaction = entityManager.getTransaction();
        if(entityManager.find(Person.class, person.getId()) != null) {
            transaction.begin();
            entityManager.merge(person);
            transaction.commit();
            log.info("Successfully update note with id=" + person.getId());
        } else {
            throw new NoteNotFoundException("Updating operation failed. A note with id=" +  person.getId() + " not exists");
        }

    }
}