robertli.zero.dao.impl.GenericHibernateDao.java Source code

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Here is the source code for robertli.zero.dao.impl.GenericHibernateDao.java

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/*
 * Copyright 2016 Robert Li.
 * Released under the MIT license
 * https://opensource.org/licenses/MIT
 */
package robertli.zero.dao.impl;

import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
import javax.annotation.Resource;
import org.hibernate.LockOptions;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import robertli.zero.dao.GenericDao;
import robertli.zero.model.SearchResult;

/**
 *
 * @version 1.0 2016.09-17
 * @author Robert Li
 * @param <T> The Entity Class
 * @param <PK> The Type of ID
 */
public class GenericHibernateDao<T extends Serializable, PK extends Serializable> implements GenericDao<T, PK> {

    @Resource
    private SessionFactory sessionFactory;

    private Class<T> entityClass;

    public GenericHibernateDao() {
        this.entityClass = null;
        Type type = getClass().getGenericSuperclass();
        if (type instanceof ParameterizedType) {
            Type[] p = ((ParameterizedType) type).getActualTypeArguments();
            this.entityClass = (Class<T>) p[0];
        }
    }

    private Session getSession() {
        return sessionFactory.getCurrentSession();
    }

    @Override
    public T get(PK id) {
        return (T) getSession().get(entityClass, id);
    }

    @Override
    public T getForUpdate(PK id) {
        return (T) getSession().get(entityClass, id, LockOptions.UPGRADE);
    }

    @Override
    public boolean isExist(PK id) {
        return get(id) != null;
    }

    @Override
    public void save(T entity) {
        getSession().save(entity);
    }

    @Override
    public void saveOrUpdate(T entity) {
        getSession().saveOrUpdate(entity);
    }

    @Override
    public void delete(T entity) {
        getSession().delete(entity);
    }

    @Override
    public void deleteById(PK id) {
        getSession().delete(get(id));
    }

    @Override
    public List<T> list() {
        return getSession().createQuery("from " + entityClass.getName()).list();
    }

    @Override
    public List<T> list(int max) {
        Session session = getSession();
        Query query = session.createQuery("from " + entityClass.getName());
        query.setMaxResults(max);
        return query.list();
    }

    @Override
    public List<T> list(int first, int max) {
        Session session = getSession();
        Query query = session.createQuery("from " + entityClass.getName());
        query.setFirstResult(first);
        query.setMaxResults(max);
        return query.list();
    }

    @Override
    public List<T> listDesc() {
        Session session = getSession();
        Query query = session.createQuery("from " + entityClass.getName() + " desc");
        return query.list();
    }

    @Override
    public List<T> listDesc(int max) {
        Session session = getSession();
        Query query = session.createQuery("from " + entityClass.getName() + " desc");
        query.setMaxResults(max);
        return query.list();
    }

    @Override
    public List<T> listDesc(int first, int max) {
        Session session = getSession();
        Query query = session.createQuery("from " + entityClass.getName() + " desc");
        query.setFirstResult(first);
        query.setMaxResults(max);
        return query.list();
    }

    public SearchResult<T> query(String hql, int pageId, int max) {
        Session session = getSession();
        Query countQuery = session.createQuery("select count(*) " + hql);
        Number number = (Number) countQuery.uniqueResult();
        int count = number.intValue();

        int start = (pageId - 1) * max;
        Query query = session.createQuery(hql);
        query.setFirstResult(start);
        query.setMaxResults(max);
        List<T> list = query.list();

        return new SearchResult<>(start, max, count, list);
    }

}