org.reusables.access.AbstractHibernateRepository.java Source code

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Here is the source code for org.reusables.access.AbstractHibernateRepository.java

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/*
 * Copyright 2010-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.reusables.access;

import static java.lang.String.format;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.util.List;

import org.apache.commons.lang.Validate;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Order;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;

/**
 * Abstract implementation, using {@link SessionFactory}, for the {@link GeneralRepository} interface
 * offering a number a standard methods generic for most repostories.
 * @author marcel
 * @param <T> Entity type for this repository.
 * @since 1.1
 **/
public abstract class AbstractHibernateRepository<T> implements GeneralRepository<T>, InitializingBean {
    private final Class<T> entityClass;
    private SessionFactory sessionFactory;

    /**
     * Spring's way of handling multiple Hibernate versions:
     * 
     * A Method handle for the <code>SessionFactory.getCurrentSession()</code> method.
     * The return value differs between Hibernate 3.x and 4.x; for cross-compilation purposes,
     * we have to use reflection here as long as we keep supporting Hibernate 3.x.
     */
    private static final Method getCurrentSessionMethod = ClassUtils.getMethod(SessionFactory.class,
            "getCurrentSession");

    /**
     * Constructor.
     */
    protected AbstractHibernateRepository() {
        this(null);
    }

    /**
     * Constructor.
     * 
     * @param sessionFactory The session factory to use.
     * @since 1.2.1
     */
    @SuppressWarnings("unchecked")
    protected AbstractHibernateRepository(final SessionFactory sessionFactory) {
        this.entityClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass())
                .getActualTypeArguments()[0];
        this.sessionFactory = sessionFactory;
    }

    /**
     * @param sessionFactory The Hibernate session factory to use.
     */
    public void setSessionFactory(final SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Validate.notNull(this.sessionFactory, "No sessionFactory supplied.");
    }

    @Override
    public T getById(final Serializable id) {
        final T entity = (T) getSession().get(this.entityClass, id);
        Validate.notNull(entity, "No entity found with id: " + id);
        return entity;
    }

    @Override
    public List<T> findAll(final String orderByPropertyName) // TODO cachable boolean
    {
        final DetachedCriteria crit = DetachedCriteria.forClass(this.entityClass);

        if (orderByPropertyName != null) {
            crit.addOrder(Order.asc(orderByPropertyName));
        }

        return findByCriteria(crit);
    }

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

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

    @Override
    public int deleteById(final Serializable id) {
        return deleteById(id, DEFAULT_ID);
    }

    @Override
    public int deleteById(final Serializable id, final String idPropertyName) {
        final String hql = format("delete %s where %s = :entityId", this.entityClass.getName(), idPropertyName);
        final Query query = getSession().createQuery(hql);
        query.setParameter("entityId", id);
        return query.executeUpdate();
    }

    /**
     * @param criteria The criteria to use for the query.
     * @return The result found.
     */
    protected List<T> findByCriteria(final DetachedCriteria criteria) // TODO support first, max results, TODO different entity class. TODO cachable boolean
    {
        return criteria.getExecutableCriteria(getSession()).list();
    }

    /**
     * @return The currect session.
     * @since 1.2.0
     */
    protected Session getSession() {
        return (Session) ReflectionUtils.invokeMethod(getCurrentSessionMethod, this.sessionFactory);
    }
}