net.derquinse.common.orm.hib.HibernateGeneralDAO.java Source code

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Here is the source code for net.derquinse.common.orm.hib.HibernateGeneralDAO.java

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/*
 * Copyright (C) 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 net.derquinse.common.orm.hib;

import java.io.Serializable;
import java.util.List;
import java.util.Map;

import net.derquinse.common.orm.Entity;
import net.derquinse.common.orm.GeneralDAO;

import org.hibernate.Criteria;
import org.hibernate.LockOptions;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;

/**
 * Implementation of the General DAO.
 * @author Andres Rodriguez
 */
public class HibernateGeneralDAO extends AbstractHibernateDAO implements GeneralDAO {
    /**
     * Constructs the DAO
     * @param sessionFactory Hibernate Session factory.
     */
    public HibernateGeneralDAO(final SessionFactory sessionFactory) {
        super(sessionFactory);
    }

    /**
     * Constructs the DAO
     */
    public HibernateGeneralDAO() {
    }

    /**
     * Returns a new criteria object.
     * @param type Entity type.
     * @return A new criteria object.
     */
    protected final Criteria newCriteria(Class<?> type) {
        return getSession().createCriteria(type);
    }

    /**
     * Apply some criteria.
     */
    private Criteria apply(Criteria criteria, Criterion... criterion) {
        for (Criterion c : criterion) {
            criteria.add(c);
        }
        return criteria;
    }

    /**
     * Returns the list of entity instances that matches the provided criteria.
     * @param type Entity type.
     * @param criteria Base criteria.
     * @param criterion Additional criteria.
     * @return The results.
     */
    protected final <T> List<T> findByCriteria(Class<T> type, Criteria criteria, Criterion... criterion) {
        @SuppressWarnings("unchecked")
        final List<T> list = apply(criteria, criterion).list();
        return list;
    }

    /**
     * Returns the list of entity instances that matches the provided criteria.
     * @param type Entity type.
     * @param criterion Search criteria.
     * @return The results.
     */
    protected final <T> List<T> findByCriteria(Class<T> type, Criterion... criterion) {
        return findByCriteria(type, newCriteria(type), criterion);
    }

    /**
     * Returns the unique entity instance that matches the provided criteria.
     * @param type Entity type.
     * @param criteria Base criteria.
     * @param criterion Additional criteria.
     * @return The result of {@code null} if no entity matches.
     */
    protected final <T> T unique(Class<T> type, Criteria criteria, Criterion... criterion) {
        @SuppressWarnings("unchecked")
        final T result = (T) apply(criteria, criterion).uniqueResult();
        return result;
    }

    /**
     * Returns the unique entity instance that matches the provided criteria.
     * @param type Entity type.
     * @param criterion Search criteria.
     * @return The result of {@code null} if no entity matches.
     */
    protected final <T> T unique(Class<T> type, Criterion... criterion) {
        @SuppressWarnings("unchecked")
        final T result = (T) apply(newCriteria(type), criterion).uniqueResult();
        return result;
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#delete(java.lang.Object)
     */
    public void delete(Object entity) {
        getSession().delete(entity);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#deleteById(java.lang.Class, java.io.Serializable)
     */
    public <T> void deleteById(Class<T> type, Serializable id) {
        Object entity = findById(type, id, true);
        if (entity != null) {
            delete(entity);
        }
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#findAll(java.lang.Class)
     */
    public <T> List<T> findAll(Class<T> type) {
        return findByCriteria(type);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#findById(java.lang.Class, java.io.Serializable,
     * boolean)
     */
    @SuppressWarnings("unchecked")
    public <T> T findById(Class<T> type, Serializable id, boolean lock) {
        if (lock) {
            return (T) getSession().get(type, id, LockOptions.UPGRADE);
        }
        return (T) getSession().get(type, id);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#save(java.lang.Object)
     */
    public void save(Object entity) {
        getSession().save(entity);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#saveOrUpdate(java.lang.Object)
     */
    public void saveOrUpdate(Object entity) {
        getSession().saveOrUpdate(entity);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#update(java.lang.Object)
     */
    public void update(Object entity) {
        getSession().update(entity);
    }

    /*
     * (non-Javadoc)
     * @see net.derquinse.common.orm.GeneralDAO#findByIds(java.lang.Class, java.lang.Iterable)
     */
    @Override
    public <T extends Entity<ID>, ID extends Serializable> Map<ID, T> findByIds(Class<T> type,
            Iterable<? extends ID> ids) {
        return findByIds(newCriteria(type), ids);
    }

}