java-movieservice/MoviesWebApp/src/main/java/at/technikumwien/movies/MoviesService.java

package at.technikumwien.movies;

import javax.annotation.Resource;
import javax.ejb.*;
import javax.persistence.EntityManager;
import javax.persistence.EntityNotFoundException;
import javax.persistence.PersistenceContext;
import java.util.List;
import java.util.logging.Logger;

@Stateless
public class MoviesService {
    private static final Logger LOGGER = Logger.getLogger(MoviesService.class.getName());

    @Resource
    private SessionContext context;

    @PersistenceContext(unitName = "MoviesPU")
    private EntityManager em;

    public Movies findById(long id) {
        LOGGER.info("findById() >> id=" + id);

        Movies movies = em.find(Movies.class, id);
        if (movies == null) {
            throw new EntityNotFoundException("can't find movie with id=" + id);
        }

        return movies;
    }

    public List<Movies> findByTitle(String title) {
        LOGGER.info("findByTitle() >> title=" + title);

        return em.createNamedQuery("Movies.selectByTitle", Movies.class)
                .setParameter("title", "%" + title + "%")
                .getResultList();
    }

    public List<Movies> findAll() {
        LOGGER.info("findAll()");

        return em.createNamedQuery("Movies.selectAll", Movies.class) //JPQL -> java persistence query language
                .getResultList();
    }

    public void removeById(long id) {
        LOGGER.info("removeById() >> id=" + id);

        Movies movies = findById(id);
        em.remove(movies); //managed news required
    }

    public void save(Movies movies) {
        // TODO: Search for actors, studio based on fields we get
        //  If exists -> Replace by found ID
        //  Else -> Error!
        LOGGER.info("save() >> movies" + movies);

        if (movies.getId() == null) {
            em.persist(movies);
        } else {
            findById(movies.getId()); //checks if movies exists
            em.merge(movies);
        }

        // TODO: On error: context.setRollbackOnly();
        //  or: throw new EJBException("Can't save ...")
    }
}