org.brekka.commons.persistence.dao.hibernate.AbstractIdentifiableEntityHibernateDAO.java Source code

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Here is the source code for org.brekka.commons.persistence.dao.hibernate.AbstractIdentifiableEntityHibernateDAO.java

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/*
 * Copyright 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.brekka.commons.persistence.dao.hibernate;

import java.io.Serializable;
import java.util.concurrent.TimeUnit;

import javax.persistence.LockModeType;

import org.brekka.commons.persistence.dao.EntityDAO;
import org.brekka.commons.persistence.model.IdentifiableEntity;
import org.brekka.commons.persistence.support.FirstResultTransformer;
import org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.Session;

public abstract class AbstractIdentifiableEntityHibernateDAO<ID extends Serializable, Entity extends IdentifiableEntity<ID>>
        implements EntityDAO<ID, Entity> {

    @Override
    public Entity retrieveById(final ID entityId) {
        return retrieveById(entityId, LockModeType.NONE, -1, null);
    }

    /* (non-Javadoc)
     * @see org.brekka.commons.persistence.dao.EntityDAO#retrieveById(java.io.Serializable, javax.persistence.LockModeType)
     */
    @Override
    public Entity retrieveById(final ID entityId, final LockModeType lockModeType) {
        return retrieveById(entityId, lockModeType, -1, null);
    }

    /* (non-Javadoc)
     * @see org.brekka.commons.persistence.dao.EntityDAO#retrieveById(java.io.Serializable, boolean)
     */
    @SuppressWarnings("unchecked")
    @Override
    public Entity retrieveById(final ID entityId, final LockModeType lockModeType, final int timeout,
            final TimeUnit timeUnit) {
        Session session = getCurrentSession();
        LockMode lockMode = getLockMode(lockModeType);
        LockOptions lockOptions = new LockOptions(lockMode);
        if (timeout > -1) {
            lockOptions.setTimeOut((int) timeUnit.toMillis(timeout));
        }
        Entity entity = (Entity) session.get(type(), entityId, lockOptions);
        preRead(entity);
        return entity;
    }

    @Override
    public ID create(final Entity entity) {
        preModify(entity);
        Session session = getCurrentSession();
        session.save(entity);
        return entity.getId();
    }

    @Override
    public void update(final Entity entity) {
        preModify(entity);
        Session session = getCurrentSession();
        session.update(entity);
    }

    @Override
    public void delete(final ID entityId) {
        Session session = getCurrentSession();
        Object toDelete = session.get(type(), entityId);
        session.delete(toDelete);
    }

    /**
     * Called with the entity prior to it being created or updated.
     * @param entity
     */
    protected void preModify(final Entity entity) {
        // Hook
    }

    /**
     * Provide an opportunity to inpect and change the entity prior to be returned
     * by the retrieve operations.
     *
     * @param entity
     */
    protected void preRead(final Entity entity) {
        // Hook
    }

    protected abstract Class<Entity> type();

    protected abstract Session getCurrentSession();

    protected Entity queryById(final ID entityId, final String idFieldName, final String hql,
            final LockModeType lockModeType, final int timeout, final TimeUnit timeUnit) {
        LockMode lockMode = getLockMode(lockModeType);
        LockOptions lockOptions = new LockOptions(lockMode);
        if (timeout > -1) {
            lockOptions.setTimeOut((int) timeUnit.toMillis(timeout));
        }
        Entity entity = type().cast(
                getCurrentSession().createQuery(hql).setLockOptions(lockOptions).setParameter(idFieldName, entityId)
                        .setResultTransformer(FirstResultTransformer.INSTANCE).uniqueResult());
        preRead(entity);
        return entity;
    }

    /**
     * Borrowed from org.hibernate.ejb.util.LockModeTypeHelper
     * @param lockMode
     * @return
     */
    public static LockMode getLockMode(final LockModeType lockMode) {
        switch (lockMode) {
        case READ:
        case OPTIMISTIC: {
            return LockMode.OPTIMISTIC;
        }
        case OPTIMISTIC_FORCE_INCREMENT:
        case WRITE: {
            return LockMode.OPTIMISTIC_FORCE_INCREMENT;
        }
        case PESSIMISTIC_READ: {
            return LockMode.PESSIMISTIC_READ;
        }
        case PESSIMISTIC_WRITE: {
            return LockMode.PESSIMISTIC_WRITE;
        }
        case PESSIMISTIC_FORCE_INCREMENT: {
            return LockMode.PESSIMISTIC_FORCE_INCREMENT;
        }
        case NONE: {
            return LockMode.NONE;
        }
        default: {
            throw new IllegalStateException("Unknown LockModeType: " + lockMode);
        }
        }
    }

}