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package jpa.controllers;
import java.io.Serializable;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import entity.Courses;
import entity.Lecture;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import jpa.controllers.exceptions.NonexistentEntityException;
/**
*
* @author atap
*/
public class LectureJpaController implements Serializable {
public LectureJpaController() {
}
public LectureJpaController(EntityManagerFactory emf) {
this.emf = emf;
}
private EntityManagerFactory emf = Persistence.createEntityManagerFactory("EducationXPU");
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
public void create(Lecture lecture) {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
Courses courseId = lecture.getCourseId();
if (courseId != null) {
courseId = em.getReference(courseId.getClass(), courseId.getCourseId());
lecture.setCourseId(courseId);
}
em.persist(lecture);
if (courseId != null) {
courseId.getLectureList().add(lecture);
courseId = em.merge(courseId);
}
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public void edit(Lecture lecture) throws NonexistentEntityException, Exception {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
Lecture persistentLecture = em.find(Lecture.class, lecture.getId());
Courses courseIdOld = persistentLecture.getCourseId();
Courses courseIdNew = lecture.getCourseId();
if (courseIdNew != null) {
courseIdNew = em.getReference(courseIdNew.getClass(), courseIdNew.getCourseId());
lecture.setCourseId(courseIdNew);
}
lecture = em.merge(lecture);
if (courseIdOld != null && !courseIdOld.equals(courseIdNew)) {
courseIdOld.getLectureList().remove(lecture);
courseIdOld = em.merge(courseIdOld);
}
if (courseIdNew != null && !courseIdNew.equals(courseIdOld)) {
courseIdNew.getLectureList().add(lecture);
courseIdNew = em.merge(courseIdNew);
}
em.getTransaction().commit();
} catch (Exception ex) {
String msg = ex.getLocalizedMessage();
if (msg == null || msg.length() == 0) {
Integer id = lecture.getId();
if (findLecture(id) == null) {
throw new NonexistentEntityException("The lecture with id " + id + " no longer exists.");
}
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
public void destroy(Integer id) throws NonexistentEntityException {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
Lecture lecture;
try {
lecture = em.getReference(Lecture.class, id);
lecture.getId();
} catch (EntityNotFoundException enfe) {
throw new NonexistentEntityException("The lecture with id " + id + " no longer exists.", enfe);
}
Courses courseId = lecture.getCourseId();
if (courseId != null) {
courseId.getLectureList().remove(lecture);
courseId = em.merge(courseId);
}
em.remove(lecture);
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public List<Lecture> findLectureEntities() {
return findLectureEntities(true, -1, -1);
}
public List<Lecture> findLectureEntities(int maxResults, int firstResult) {
return findLectureEntities(false, maxResults, firstResult);
}
private List<Lecture> findLectureEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(Lecture.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
public Lecture findLecture(Integer id) {
EntityManager em = getEntityManager();
try {
return em.find(Lecture.class, id);
} finally {
em.close();
}
}
public int getLectureCount() {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
Root<Lecture> rt = cq.from(Lecture.class);
cq.select(em.getCriteriaBuilder().count(rt));
Query q = em.createQuery(cq);
return ((Long) q.getSingleResult()).intValue();
} finally {
em.close();
}
}
}