de.tuclausthal.submissioninterface.persistence.dao.impl.GroupDAO.java Source code

Introduction

Here is the source code for de.tuclausthal.submissioninterface.persistence.dao.impl.GroupDAO.java

Source

/*
 * Copyright 2009 - 2010 Sven Strickroth <email@cs-ware.de>
 * 
 * This file is part of the SubmissionInterface.
 * 
 * SubmissionInterface is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 * 
 * SubmissionInterface 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 SubmissionInterface. If not, see <http://www.gnu.org/licenses/>.
 */

package de.tuclausthal.submissioninterface.persistence.dao.impl;

import java.util.List;

import org.hibernate.LockMode;
import org.hibernate.Session;
import org.hibernate.criterion.Restrictions;

import de.tuclausthal.submissioninterface.persistence.dao.GroupDAOIf;
import de.tuclausthal.submissioninterface.persistence.datamodel.Group;
import de.tuclausthal.submissioninterface.persistence.datamodel.Lecture;
import de.tuclausthal.submissioninterface.persistence.datamodel.Participation;

/**
 * Data Access Object implementation for the GroupDAOIf
 * @author Sven Strickroth
 */
public class GroupDAO extends AbstractDAO implements GroupDAOIf {
    public GroupDAO(Session session) {
        super(session);
    }

    @Override
    public Group createGroup(Lecture lecture, String name, boolean allowStudentsToSignup,
            boolean allowStudentsToQuit, int maxStudents) {
        Session session = getSession();
        Group group = new Group();
        group.setName(name);
        group.setLecture(lecture);
        group.setAllowStudentsToSignup(allowStudentsToSignup);
        group.setAllowStudentsToQuit(allowStudentsToQuit);
        group.setMaxStudents(maxStudents);
        session.save(group);
        return group;
    }

    @Override
    public void deleteGroup(Group group) {
        Session session = getSession();
        session.lock(group, LockMode.UPGRADE);
        for (Participation participation : group.getMembers()) {
            participation.setGroup(null);
            session.update(participation);
        }
        session.update(group);
        session.delete(group);
    }

    @Override
    public Group getGroup(int groupid) {
        return (Group) getSession().get(Group.class, groupid);
    }

    @Override
    public Group getGroupLocked(int groupid) {
        return (Group) getSession().get(Group.class, groupid, LockMode.UPGRADE);
    }

    @Override
    public void saveGroup(Group group) {
        Session session = getSession();
        session.update(group);
    }

    @Override
    public List<Group> getJoinAbleGroups(Lecture lecture, Group participationGroup) {
        if (participationGroup == null) {
            return getSession().createCriteria(Group.class).add(Restrictions.eq("lecture", lecture))
                    .add(Restrictions.eq("allowStudentsToSignup", true))
                    .add(Restrictions.sqlRestriction(
                            "(select count(*) from participations where groupid={alias}.gid) < this_.maxStudents"))
                    .list();
        } else {
            return getSession().createCriteria(Group.class).add(Restrictions.eq("lecture", lecture))
                    .add(Restrictions.eq("allowStudentsToSignup", true))
                    .add(Restrictions.sqlRestriction(
                            "(select count(*) from participations where groupid={alias}.gid) < this_.maxStudents"))
                    .add(Restrictions.not(Restrictions.eq("gid", participationGroup.getGid()))).list();
        }
    }
}