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 * and open the template in the editor.
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package org.ufcspa.simdecs.bn.jpa;

import java.io.Serializable;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import org.ufcspa.simdecs.bn.entity.Node;
import org.ufcspa.simdecs.bn.entity.Answer;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.transaction.UserTransaction;
import org.ufcspa.simdecs.bn.entity.Question;
import org.ufcspa.simdecs.bn.jpa.exceptions.NonexistentEntityException;
import org.ufcspa.simdecs.bn.jpa.exceptions.RollbackFailureException;

/**
 *
 * @author mchelem
 */
public class QuestionJpaController implements Serializable {

    public QuestionJpaController(UserTransaction utx, EntityManagerFactory emf) {
        this.utx = utx;
        this.emf = emf;
    }
    private UserTransaction utx = null;
    private EntityManagerFactory emf = null;

    public EntityManager getEntityManager() {
        return emf.createEntityManager();
    }

    public void create(Question question) throws RollbackFailureException, Exception {
        if (question.getAnswers() == null) {
            question.setAnswers(new ArrayList<Answer>());
        }
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            Node node = question.getNode();
            if (node != null) {
                node = em.getReference(node.getClass(), node.getId());
                question.setNode(node);
            }
            List<Answer> attachedAnswers = new ArrayList<Answer>();
            for (Answer answersAnswerToAttach : question.getAnswers()) {
                answersAnswerToAttach = em.getReference(answersAnswerToAttach.getClass(), answersAnswerToAttach.getId());
                attachedAnswers.add(answersAnswerToAttach);
            }
            question.setAnswers(attachedAnswers);
            em.persist(question);
            if (node != null) {
                node.getQuestions().add(question);
                node = em.merge(node);
            }
            for (Answer answersAnswer : question.getAnswers()) {
                Question oldQuestionOfAnswersAnswer = answersAnswer.getQuestion();
                answersAnswer.setQuestion(question);
                answersAnswer = em.merge(answersAnswer);
                if (oldQuestionOfAnswersAnswer != null) {
                    oldQuestionOfAnswersAnswer.getAnswers().remove(answersAnswer);
                    oldQuestionOfAnswersAnswer = em.merge(oldQuestionOfAnswersAnswer);
                }
            }
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public void edit(Question question) throws NonexistentEntityException, RollbackFailureException, Exception {
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            Question persistentQuestion = em.find(Question.class, question.getId());
            Node nodeOld = persistentQuestion.getNode();
            Node nodeNew = question.getNode();
            List<Answer> answersOld = persistentQuestion.getAnswers();
            List<Answer> answersNew = question.getAnswers();
            if (nodeNew != null) {
                nodeNew = em.getReference(nodeNew.getClass(), nodeNew.getId());
                question.setNode(nodeNew);
            }
            List<Answer> attachedAnswersNew = new ArrayList<Answer>();
            for (Answer answersNewAnswerToAttach : answersNew) {
                answersNewAnswerToAttach = em.getReference(answersNewAnswerToAttach.getClass(), answersNewAnswerToAttach.getId());
                attachedAnswersNew.add(answersNewAnswerToAttach);
            }
            answersNew = attachedAnswersNew;
            question.setAnswers(answersNew);
            question = em.merge(question);
            if (nodeOld != null && !nodeOld.equals(nodeNew)) {
                nodeOld.getQuestions().remove(question);
                nodeOld = em.merge(nodeOld);
            }
            if (nodeNew != null && !nodeNew.equals(nodeOld)) {
                nodeNew.getQuestions().add(question);
                nodeNew = em.merge(nodeNew);
            }
            for (Answer answersOldAnswer : answersOld) {
                if (!answersNew.contains(answersOldAnswer)) {
                    answersOldAnswer.setQuestion(null);
                    answersOldAnswer = em.merge(answersOldAnswer);
                }
            }
            for (Answer answersNewAnswer : answersNew) {
                if (!answersOld.contains(answersNewAnswer)) {
                    Question oldQuestionOfAnswersNewAnswer = answersNewAnswer.getQuestion();
                    answersNewAnswer.setQuestion(question);
                    answersNewAnswer = em.merge(answersNewAnswer);
                    if (oldQuestionOfAnswersNewAnswer != null && !oldQuestionOfAnswersNewAnswer.equals(question)) {
                        oldQuestionOfAnswersNewAnswer.getAnswers().remove(answersNewAnswer);
                        oldQuestionOfAnswersNewAnswer = em.merge(oldQuestionOfAnswersNewAnswer);
                    }
                }
            }
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            String msg = ex.getLocalizedMessage();
            if (msg == null || msg.length() == 0) {
                Long id = question.getId();
                if (findQuestion(id) == null) {
                    throw new NonexistentEntityException("The question with id " + id + " no longer exists.");
                }
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public void destroy(Long id) throws NonexistentEntityException, RollbackFailureException, Exception {
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            Question question;
            try {
                question = em.getReference(Question.class, id);
                question.getId();
            } catch (EntityNotFoundException enfe) {
                throw new NonexistentEntityException("The question with id " + id + " no longer exists.", enfe);
            }
            Node node = question.getNode();
            if (node != null) {
                node.getQuestions().remove(question);
                node = em.merge(node);
            }
            List<Answer> answers = question.getAnswers();
            for (Answer answersAnswer : answers) {
                answersAnswer.setQuestion(null);
                answersAnswer = em.merge(answersAnswer);
            }
            em.remove(question);
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public List<Question> findQuestionEntities() {
        return findQuestionEntities(true, -1, -1);
    }

    public List<Question> findQuestionEntities(int maxResults, int firstResult) {
        return findQuestionEntities(false, maxResults, firstResult);
    }

    private List<Question> findQuestionEntities(boolean all, int maxResults, int firstResult) {
        EntityManager em = getEntityManager();
        try {
            CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
            cq.select(cq.from(Question.class));
            Query q = em.createQuery(cq);
            if (!all) {
                q.setMaxResults(maxResults);
                q.setFirstResult(firstResult);
            }
            return q.getResultList();
        } finally {
            em.close();
        }
    }

    public Question findQuestion(Long id) {
        EntityManager em = getEntityManager();
        try {
            return em.find(Question.class, id);
        } finally {
            em.close();
        }
    }

    public int getQuestionCount() {
        EntityManager em = getEntityManager();
        try {
            CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
            Root<Question> rt = cq.from(Question.class);
            cq.select(em.getCriteriaBuilder().count(rt));
            Query q = em.createQuery(cq);
            return ((Long) q.getSingleResult()).intValue();
        } finally {
            em.close();
        }
    }
    
}