Hibernate Inheritance

/**
 *
 */
package com.hibernate.venkat;

import javax.persistence.Entity;

/**
 * @author Venkat
 *
 */
@Entity
public class Module extends Project {

private String ModuleName;

public String getModuleName() {
return ModuleName;
}

public void setModuleName(String moduleName) {
ModuleName = moduleName;
}
}

---------------------------------------------------------------------------------------------

package com.hibernate.venkat;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.Inheritance;

import javax.persistence.InheritanceType;

/**

 * @author Venkat

 *

 */

@Entity

@Inheritance(strategy=InheritanceType.JOINED)

public class Project {

private int projectId;

private String projectName;

@Id

@GeneratedValue

public int getProjectId() {

return projectId;

}

public void setProjectId(int projectId) {

this.projectId = projectId;

}

public String getProjectName() {

return projectName;

}

public void setProjectName(String projectName) {

this.projectName = projectName;

}

}

---------------------------------------------------------------------------------------------

/**

 * 

 */

package com.hibernate.venkat;

import javax.persistence.Entity;

/**

 * @author Venkat

 *

 */

@Entity

public class Task extends Module{

private String taskName;

public String getTaskName() {

return taskName;

}

public void setTaskName(String taskName) {

this.taskName = taskName;

}

}

---------------------------------------------------------------------------------------------

/**

 * 

 */

package com.hibernate.venkat;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.AnnotationConfiguration;

import org.hibernate.tool.hbm2ddl.SchemaExport;

/**

 * @author Venkat

 *

 */

public class TestInheritance {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

AnnotationConfiguration config=new AnnotationConfiguration();

config.addAnnotatedClass(Project.class);

config.addAnnotatedClass(Module.class);

config.addAnnotatedClass(Task.class);

config.configure("hibernate.cfg.xml");

new SchemaExport(config).create(true, true);

SessionFactory factory=config.buildSessionFactory();

Session session=factory.getCurrentSession();

session.beginTransaction();

Project p=new Project();

p.setProjectName("Hibernate Project");

Module m=new Module();

m.setProjectName("Spring AOP");

m.setModuleName("AOP");

Task t=new Task();

t.setProjectName("JAVA");

t.setModuleName("Collections");

t.setTaskName("ArrayList");

session.save(p);

session.save(m);

session.save(t);

session.getTransaction().commit();

t=null;

session=factory.openSession();

session.beginTransaction();

t=(Task)session.get(Task.class, 3);

System.out.println("Task Object "+t.getProjectName());

}}

------------------------------------------------------------------------------

<?xml version='1.0' encoding='utf-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->

        <property name="connection.driver_class">oracle.jdbc.OracleDriver</property>

        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>

        <property name="connection.username">venkat</property>

        <property name="connection.password">venkat</property>

        <!-- JDBC connection pool (use the built-in) -->

        <property name="connection.pool_size">2</property>

        <!-- SQL dialect -->

        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>

        <!-- Enable Hibernate's current session context -->

        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->

        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->

        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->

<!--         <property name="hbm2ddl.auto">create</property> -->

<!--         <mapping resource="org/hibernate/tutorial/domain/Event.hbm.xml"/> -->

<!--         <mapping resource="org/hibernate/tutorial/domain/Person.hbm.xml"/> -->

    </session-factory>

</hibernate-configuration>