001    // Copyright 2007-2008 Thiago H. de Paula Figueiredo
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package br.com.arsmachina.dao.hibernate;
016    
017    import java.io.Serializable;
018    
019    import org.hibernate.EntityMode;
020    import org.hibernate.Query;
021    import org.hibernate.SessionFactory;
022    import org.hibernate.classic.Session;
023    import org.hibernate.metadata.ClassMetadata;
024    
025    import br.com.arsmachina.dao.WriteableDAO;
026    
027    /**
028     * {@link WriteableDAO} implementation using Hibernate. All methods use {@link #getSession()} to get
029     * a {@link Session}.
030     * 
031     * @author Thiago H. de Paula Figueiredo
032     * @param <T> the entity class related to this DAO.
033     * @param <K> the type of the field that represents the entity class' primary key.
034     */
035    public abstract class WriteableDAOImpl<T, K extends Serializable> extends BaseHibernateDAO<T, K>
036                    implements WriteableDAO<T, K> {
037    
038            final private String deleteHQL;
039    
040            /**
041             * Constructor that takes a {@link Class} and a {@link SessionFactory}.
042             * 
043             * @param clasz a {@link Class}.
044             * @param sessionFactory a {@link SessionFactory}. It cannot be null.
045             */
046            public WriteableDAOImpl(SessionFactory sessionFactory) {
047                    this(null, sessionFactory);
048            }
049    
050            /**
051             * Constructor that takes a {@link Class} and a {@link SessionFactory}.
052             * 
053             * @param clasz a {@link Class}.
054             * @param sessionFactory a {@link SessionFactory}. It cannot be null.
055             */
056            @SuppressWarnings("unchecked")
057            public WriteableDAOImpl(Class<T> clasz, SessionFactory sessionFactory) {
058                    
059                    super(clasz, sessionFactory);
060                    deleteHQL = createDeleteHQL();
061                    
062            }
063    
064            /**
065             * Creates an HQL query used to delete an object given its primary key value.
066             * 
067             * @return a {@link String}.
068             */
069            String createDeleteHQL() {
070    
071                    return "delete from " + getEntityClass().getName() + " where "
072                                    + getPrimaryKeyPropertyName() + " = :id";
073    
074            }
075    
076            public void delete(K id) {
077    
078                    Query query = getSession().createQuery(deleteHQL);
079                    query.setParameter("id", id);
080                    query.executeUpdate();
081    
082            }
083    
084            public void delete(T object) {
085                    getSession().delete(object);
086            }
087    
088            public void evict(T object) {
089                    getSession().evict(object);
090            }
091    
092            public void save(T object) {
093                    getSession().save(object);
094            }
095            
096            public T update(T object) {
097                    
098                    if (isPersistent(object) == false) {
099                            throw new IllegalArgumentException("Object not persistent");
100                    }
101                    
102                    getSession().update(object);
103                    return object;
104                    
105            }
106    
107            /**
108             * Returns <code>true</code> if the primary key field (identifier) of the given object is not
109             * null. Its value is obtained via {@link ClassMetadata#getIdentifier(Object, EntityMode)}.
110             * 
111             * @see br.com.arsmachina.dao.WriteableDAO#isPersistent(java.lang.Object)
112             * @throws IllegalArgumentException if <code>object</code> is null.
113             */
114            public boolean isPersistent(T object) {
115                    
116                    if (object == null) {
117                            throw new IllegalArgumentException("Parameter object cannot be null");
118                    }
119                    
120                    return getClassMetadata().getIdentifier(object, EntityMode.POJO) != null;
121                    
122            }
123    
124    }