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package dbcontrollers;
import dbbeans.Fields;
import dbcontrollers.exceptions.NonexistentEntityException;
import dbcontrollers.exceptions.RollbackFailureException;
import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import javax.transaction.UserTransaction;
/**
*
* @author Laur
*/
public class FieldsJpaController implements Serializable {
/**
* constructor used to instantiate this controller using a transaction and an emf
* @param utx
* @param emf
*/
public FieldsJpaController(UserTransaction utx, EntityManagerFactory emf) {
this.utx = utx;
this.emf = emf;
}
private UserTransaction utx = null;
private EntityManagerFactory emf = null;
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
// method used to add a new row in the DB table
public void create(Fields fields) throws RollbackFailureException, Exception {
EntityManager em = null;
try {
utx.begin(); // begin of the transaction
em = getEntityManager(); // call for em
em.persist(fields); // call of persist to add the new row
utx.commit(); // commit of the transaction
} catch (Exception ex) {
try {
utx.rollback(); // rollback the transaction in case of exception
} catch (Exception re) {
throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
/**
* Method used to update a row in the table
* @param fields
* @throws NonexistentEntityException
* @throws RollbackFailureException
* @throws Exception
*/
public void edit(Fields fields) throws NonexistentEntityException, RollbackFailureException, Exception {
EntityManager em = null;
try {
utx.begin(); // begin of transaction
em = getEntityManager(); // call for entity manager
fields = em.merge(fields); // update using the new information from the bean instance sent by parameter
utx.commit(); // commit the transaction
} catch (Exception ex) {
try {
utx.rollback(); // in case of an exception rollback the transaction
} 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) {
Integer id = fields.getId();
if (findFields(id) == null) {
throw new NonexistentEntityException("The fields with id " + id + " no longer exists.");
}
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
public void destroy(Integer id) throws NonexistentEntityException, RollbackFailureException, Exception {
EntityManager em = null;
try {
utx.begin();
em = getEntityManager();
Fields fields;
try {
fields = em.getReference(Fields.class, id);
fields.getId();
} catch (EntityNotFoundException enfe) {
throw new NonexistentEntityException("The fields with id " + id + " no longer exists.", enfe);
}
em.remove(fields);
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<Fields> findFieldsEntities() {
return findFieldsEntities(true, -1, -1);
}
public List<Fields> findFieldsEntities(int maxResults, int firstResult) {
return findFieldsEntities(false, maxResults, firstResult);
}
private List<Fields> findFieldsEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(Fields.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
public Fields findFields(Integer id) {
EntityManager em = getEntityManager();
try {
return em.find(Fields.class, id);
} finally {
em.close();
}
}
public int getFieldsCount() {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
Root<Fields> rt = cq.from(Fields.class);
cq.select(em.getCriteriaBuilder().count(rt));
Query q = em.createQuery(cq);
return ((Long) q.getSingleResult()).intValue();
} finally {
em.close();
}
}
}