I'm using JEE6, Oracle database 11g and Hibernate. I'm trying to make the following inheritance work :
So WikiNotification and TodoNotification extend Notification. According to the single table inheritance strategy, there will be one and one only table for those three classes in the database.
Here is Notification :
@Entity
@ForceDiscriminator
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="NOTIFICATION_TYPE")
@Table(name="SMH_NOTIFICATION")
public class Notification extends AbstractPersistentObject{
/**
*
*/
private static final long serialVersionUID = -2313098389774322743L;
@ManyToOne
@JoinColumn(name="RECEIVER_ID", nullable=false)
private Userprofile receiver;
@Column(name="CLASSIFICATION",nullable = true, length=30)
private String classification;
@Column(name="DESCRIPTION", nullable = true, length=60)
private String description;
@Column(name="DEADLINE")
@Temporal(TemporalType.DATE)
private Date deadline;
This is WikiNotification :
//@Entity
@DiscriminatorValue("Wiki")
//@Table(name="SMH_NOTIFICATION")
//@Inheritance(discriminatorValue="Wiki")
public class WikiNotification extends Notification{
/**
*
*/
private static final long serialVersionUID = 5025643991898983953L;
//the sender is the user who triggers the notification
//for example, it can the one who modifies someone else's chapters
@ManyToOne
@JoinColumn(name="SENDER_ID", nullable=false)
private Userprofile sender;
//"0" if the owner has not accepted yet, "1" if he accepted
@Column(name="ACCEPTED", length=1, nullable=false)
private String accepted;
//the notification type can be "delete", "submit" or "modify"
@Column(name="NOTIFICATIONTYPE",length=20,nullable=false)
private String notificationType;
//mofications, deletions and submissions are related to this article chapter
@ManyToOne
@JoinColumn(name="ARTICLECHAPTER",nullable=false)
private ArticleChapter chapter;
And TodoNotification :
//@Entity
@DiscriminatorValue("Todo")
//@Table(name="SMH_NOTIFICATION")
public class TodoNotification extends Notification{
/**
*
*/
private static final long serialVersionUID = 2482841237595539431L;
@OneToOne
@JoinColumn(name="TODO_ID", nullable=false)
private ToDo todo;
What is not working so far is :
- I have one table 'SMH_NOTIFICATION' created but I don't see the discriminator column 'NOTIFICATION_TYPE' and I don't have the other columns for WikiNotification and TodoNotification :
- when I write @Entity in the classes WikiNotification and TodoNotification, I have two tables Wikinotification and Todonotification created in my database, which is not what I expected. There should be only one table 'SMH_NOTIFICATION'
I tried the following tutorials but it hasn't worked yet :
http://www.dineshonjava.com/p/implementing-inheritance-in-hibernate.html#.Vd71ZiXtlHw
https://en.wikibooks.org/wiki/Java_Persistence/Inheritance
http://www.thejavageek.com/2014/05/14/jpa-single-table-inheritance-example/
http://uaihebert.com/jpa-mini-book-first-steps-and-detailed-concepts/13/
http://viralpatel.net/blogs/hibernate-inheritence-table-per-hierarchy-mapping/
Edit:
When I make Notification an abstract class and when I add @Entity in WikiNotification and TodoNotification I get the following lines in Eclipse :
INFO 27.08.15 14:45:34.996 org.hibernate.tool.hbm2ddl.DatabaseMetadata@getTableMetadata: table not found: TodoNotification
INFO 27.08.15 14:45:35.001 org.hibernate.tool.hbm2ddl.DatabaseMetadata@getTableMetadata: table not found: WikiNotification
INFO 27.08.15 14:45:35.007 org.hibernate.tool.hbm2ddl.DatabaseMetadata@getTableMetadata: table not found: TodoNotification
INFO 27.08.15 14:45:35.012 org.hibernate.tool.hbm2ddl.DatabaseMetadata@getTableMetadata: table not found: WikiNotification
So I have two tables in my database, WikiNotification and TodoNotification, whereas I only expect one table because of the single table inheritance strategy.
<hibernate-configuration>
<session-factory>
<property name="hibernate.show_sql">false</property>
<property name="hibernate.format_sql">false</property>
<property name="hibernate.bytecode.use_reflection_optimizer">false</property>
<!--
<property name="current_session_context_class">thread</property>
-->
<property name="hibernate.hbm2ddl.auto">update</property>
<!--
<property name="hibernate.show_sql">true</property>
<property name="hibernate.format_sql">true</property>
<property name="hibernate.use_sql_comments">true</property>
-->
</session-factory>
</hibernate-configuration>
DAO configuration file:
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="hibernateProperties">
<props>
<!-- Hibernate dialect can be defined in application context -->
<prop key="hibernate.dialect">%{smh.hibernate.dialect}</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.connection.SetBigStringTryClob">true</prop>
<prop key="hibernate.jdbc.batch_size">0</prop>
</props>
</property>
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan">
<list>
<value>com.smh.core.domain</value>
<!--
<value>com.seti.core.domain.entity.task.Task</value>
-->
</list>
</property>
</bean>
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- one of the properties available; the maximum file size in bytes -->
<property name="maxUploadSize" value="50000000" />
</bean>
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
@DiscriminatorValuefor the superclass. – Dragan Bozanovic