pdsanchez.mywebtools.model.dao.jpa.GenericDAOJPAImpl.java Source code

Introduction

Here is the source code for pdsanchez.mywebtools.model.dao.jpa.GenericDAOJPAImpl.java

Source

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package pdsanchez.mywebtools.model.dao.jpa;

import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import pdsanchez.mywebtools.model.dao.contract.GenericDAO;

/**
 *
 * @author pdsanchez
 * @param <T>
 * @param <PK>
 */
@Component
public abstract class GenericDAOJPAImpl<T, PK extends Serializable> implements GenericDAO<T, PK> {

    private final Class<T> entityClass;

    @PersistenceContext(unitName = "DEFAULT_PU")
    protected EntityManager em;

    public GenericDAOJPAImpl(Class<T> entityClass) {
        this.entityClass = entityClass;
    }

    protected EntityManager getEntityManager() {
        return em;
    }

    @Transactional
    @Override
    public void create(T entity) {
        getEntityManager().persist(entity);
    }

    @Transactional
    @Override
    public void update(T entity) {
        getEntityManager().merge(entity);
    }

    @Transactional
    @Override
    public void delete(T entity) {
        getEntityManager().remove(getEntityManager().merge(entity));
    }

    @Override
    public T find(PK id) {
        return getEntityManager().find(entityClass, id);
    }

    @Override
    public List<T> findAll() {
        javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
        cq.select(cq.from(entityClass));
        return getEntityManager().createQuery(cq).getResultList();
    }

    @Override
    public int count() {
        javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
        javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
        cq.select(getEntityManager().getCriteriaBuilder().count(rt));
        javax.persistence.Query q = getEntityManager().createQuery(cq);
        return ((Long) q.getSingleResult()).intValue();
    }

    //    public <T> int deleteAllEntities(Class<T> entityType) {
    //        CriteriaBuilder builder = em.getCriteriaBuilder();
    //        CriteriaDelete<T> query = builder.createCriteriaDelete(entityType);
    //        query.from(entityType);
    //        return em.createQuery(query).executeUpdate();
    //    }
}