com.cyclopsgroup.courselist.impl.DefaultCourseListService.java Source code

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Here is the source code for com.cyclopsgroup.courselist.impl.DefaultCourseListService.java

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/* ==========================================================================
 * Copyright 2002-2005 Cyclops Group Community
 *
 * Licensed under the COMMON DEVELOPMENT AND DISTRIBUTION LICENSE
 * (CDDL) Version 1.0 (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.opensource.org/licenses/cddl1.txt
 *
 *  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 com.cyclopsgroup.courselist.impl;

import java.util.Iterator;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.criterion.Expression;

import com.cyclopsgroup.courselist.CourseListService;
import com.cyclopsgroup.courselist.entity.Course;
import com.cyclopsgroup.courselist.entity.CoursePrerequisite;
import com.cyclopsgroup.courselist.entity.Teacher;
import com.cyclopsgroup.tornado.hibernate.AbstractHibernateEnabled;
import com.cyclopsgroup.tornado.hibernate.HqlLargeList;
import com.cyclopsgroup.waterview.LargeList;

/**
 * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
 *
 * Default implementation of course list
 */
public class DefaultCourseListService extends AbstractHibernateEnabled implements CourseListService {
    /**
     * Overwrite or implement method addPrerequisite()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#addPrerequisite(java.lang.String, java.lang.String)
     */
    public void addPrerequisite(String courseId, String prereqId) throws Exception {
        Session s = getHibernateSession();
        Criteria criteria = s.createCriteria(CoursePrerequisite.class);
        criteria.add(Expression.eq("courseId", courseId)).add(Expression.eq("prerequisiteId", prereqId));
        List rs = criteria.list();
        if (rs.isEmpty()) {
            CoursePrerequisite cp = new CoursePrerequisite();
            cp.setCourseId(courseId);
            cp.setPrerequisiteId(prereqId);
            s.save(cp);
        }
    }

    /**
     * Overwrite or implement method deletePrerequisite()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#deletePrerequisite(java.lang.String, java.lang.String)
     */
    public void deletePrerequisite(String courseId, String prereqId) throws Exception {
        Session s = getHibernateSession();
        Criteria criteria = s.createCriteria(CoursePrerequisite.class);
        criteria.add(Expression.eq("courseId", courseId)).add(Expression.eq("prerequisiteId", prereqId));
        List rs = criteria.list();
        for (Iterator iter = rs.iterator(); iter.hasNext();) {
            CoursePrerequisite cp = (CoursePrerequisite) iter.next();
            s.delete(cp);
        }
    }

    /**
     * Overwrite or implement method findByCode()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#findByCode(java.lang.String, java.lang.String)
     */
    public Course findByCode(String prefix, String code) throws Exception {
        Criteria criteria = getHibernateSession().createCriteria(Course.class);
        criteria.add(Expression.eq("prefix", prefix)).add(Expression.eq("courseCode", code))
                .add(Expression.eq("isDisabled", Boolean.FALSE));
        List rs = criteria.setMaxResults(1).list();
        return rs.isEmpty() ? null : (Course) rs.get(0);
    }

    /**
     * Overwrite or implement method findByTeacher()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#findByTeacher(java.lang.String)
     */
    public List findByTeacher(String teacherId) throws Exception {
        return getHibernateSession().createCriteria(Course.class).add(Expression.eq("teacherId", teacherId))
                .add(Expression.eq("isDisabled", Boolean.FALSE)).list();
    }

    /**
     * Overwrite or implement method getAllCourses()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#getAllCourses()
     */
    public LargeList getAllCourses() throws Exception {
        StringBuffer query = new StringBuffer("FROM ");
        query.append(Course.class.getName()).append(" WHERE isDisabled = 0");
        HqlLargeList list = new HqlLargeList(query.toString(), getHibernateService());
        return list;
    }

    /**
     * Overwrite or implement method getAllTeachers()
     *
     * @see com.cyclopsgroup.courselist.CourseListService#getAllTeachers()
     */
    public List getAllTeachers() throws Exception {
        return getHibernateSession().createCriteria(Teacher.class).list();
    }
}