package test;

import javax.ejb.*;

@Entity
@Table(name="CAT")
@Inheritance(strategy = InheritanceType.JOINED)
public class Cat {

    private String id;
    private String name;
    private char sex;
    private float weight;
    private int age;

    public Cat() {
    }
   
   @Id(generate=GeneratorType.IDENTITY)
    @Column(name="CAT_ID")
    public String getId() {
        return id;
    }

    private void setId(String id) {
        this.id = id;
    }

   @Column(name="name", nullable = false, length=16)
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
   
   @Column(name="gender")
    public char getSex() {
        return sex;
    }

    public void setSex(char sex) {
        this.sex = sex;
    }
   
   @Column(name="weight")
    public float getWeight() {
        return weight;
    }

    public void setWeight(float weight) {
        this.weight = weight;
    }
   
   @Column(name="age")
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

package test;

import javax.ejb.*;

@Entity
@Table(name="DCAT")
@Inheritance(strategy = InheritanceType.JOINED)
@InheritanceJoinColumn(name="DCatId")
public class DomesticCat extends Cat {
    private String c;
   
   @Column(name="c")
    public String getC() {
            return c;
    }
    protected void setC(String c) {
            this.c=c;
    }
}

package test;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.*;
import org.hibernate.cfg.*;

public class TestUtil {
    private static Log log = LogFactory.getLog(TestUtil.class);

    private static final SessionFactory sessionFactory;

    static {
        try {
         sessionFactory = new AnnotationConfiguration().configure("/test/hibernate.cfg.xml")
                     .buildSessionFactory();

            Session session = sessionFactory.openSession();
        } catch (Throwable ex) {
            log.error("Initial SessionFactory creation failed.", ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static final ThreadLocal<Session> session = new ThreadLocal<Session>();

    public static Session currentSession() throws HibernateException {
        Session s = session.get();
        // Open a new Session, if this Thread has none yet
        if (s == null) {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }

    public static void closeSession() throws HibernateException {
        Session s = (Session) session.get();
        session.set(null);
        if (s != null)
            s.close();
    }
}

    Session session = TestUtil.currentSession();
    Transaction tx = session.beginTransaction();
    System.out.println("Start!");
    DomesticCat dcat = new DomesticCat();
    dcat.setName("dCat");
    dcat.setAge(10);
    dcat.setSex('M');
    dcat.setWeight((float) 7.6);
    dcat.setC("haha");
    session.save(dcat);
    tx.commit();
    [b]TestUtil.closeSession();
    session = TestUtil.currentSession();[/b]
    Query query = session.createQuery("select d from DomesticCat as d");
    for (Iterator it = query.iterate(); it.hasNext();) {
        Cat cat = (Cat) it.next();
        System.out.println("*************************************************");
        System.out.println("Cat: " + cat.getName() + cat.getSex());
        if (cat instanceof DomesticCat) {
            System.out.println("DomesticCat: " + ((DomesticCat) cat).getC());
        }
    }
    TestUtil.closeSession();