com.eucalyptus.cloudwatch.common.internal.domain.NextTokenUtils.java Source code

Introduction

Here is the source code for com.eucalyptus.cloudwatch.common.internal.domain.NextTokenUtils.java

Source

/*************************************************************************
 * Copyright 2009-2013 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.cloudwatch.common.internal.domain;

import java.util.Date;

import org.hibernate.Criteria;
import org.hibernate.criterion.Junction;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;

import com.eucalyptus.entities.AbstractPersistent;
import com.eucalyptus.entities.Entities;

public class NextTokenUtils {

    private NextTokenUtils() {
    }

    public static Date getNextTokenCreatedTime(String nextToken, Class<? extends AbstractPersistent> clazz)
            throws InvalidTokenException {
        Date nextTokenCreated = null;
        if (nextToken != null) {
            Criteria nextTokenCriteria = Entities.createCriteria(clazz);
            nextTokenCriteria.add(Restrictions.eq("naturalId", nextToken));
            AbstractPersistent nextTokenEntity = (AbstractPersistent) nextTokenCriteria.uniqueResult();
            if (nextTokenEntity != null) {
                nextTokenCreated = nextTokenEntity.getCreationTimestamp();
            } else {
                throw new InvalidTokenException("The token '" + nextToken + "' was invalid");
            }
        }
        return nextTokenCreated;
    }

    public static Criteria addNextTokenConstraints(Integer maxRecords, String nextToken, Date nextTokenCreated,
            Criteria criteria) {
        if (nextTokenCreated != null) {
            // add (WHERE creationTimestamp > nextTokenCreated OR 
            // (creationTimestamp = nextTokenCreated AND naturalId > nextToken
            Junction or = Restrictions.disjunction();
            or.add(Restrictions.gt("creationTimestamp", nextTokenCreated));
            Junction and = Restrictions.conjunction();
            and.add(Restrictions.eq("creationTimestamp", nextTokenCreated));
            and.add(Restrictions.gt("naturalId", nextToken));
            or.add(and);
            criteria.add(or);
        }
        criteria.addOrder(Order.asc("creationTimestamp"));
        criteria.addOrder(Order.asc("naturalId"));
        if (maxRecords != null) {
            criteria.setMaxResults(maxRecords);
        }
        return criteria;
    }

}