hb : Version maintenance in Hibernate

Employee.java
=============

package mypack;
public class Employee {
    private int id;
    private String name;
    private String address;
    private int v;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public int getV() {
        return v;
    }

    public void setV(int v) {
        this.v = v;
    }
}

employee.hbm.xml
=================

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="mypack.Employee" table="Empversion" >
        <id name="id" >
            <generator class="native" />
        </id>
        <version name="v" column="ver" />
        <property name="name" column="name" ></property>
        <property name="address" column="address" ></property>
    </class>
</hibernate-mapping>

hibernate.cfg.xml
==================

<?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>
    <property name="hibernate.dialect">org.hibernate.dialect.DerbyDialect</property>
    <property name="hibernate.connection.driver_class">org.apache.derby.jdbc.ClientDriver</property>
    <property name="hibernate.connection.url">jdbc:derby://localhost:1527/version</property>
    <property name="hibernate.connection.username">app</property>
    <property name="hibernate.connection.password">app</property>
    <property name="show_sql">true</property>
    <property name="hbm2ddl.auto">update</property>
    <mapping resource="employee.hbm.xml"/>
  </session-factory>
</hibernate-configuration>


SaveData.java
=============

package mypack;
import org.hibernate.cfg.*;
import org.hibernate.*;

public class SaveData {
    static SessionFactory sessionFactory;

    public static void main(String[] args) {
      sessionFactory = new Configuration().configure().buildSessionFactory();
      Session session = sessionFactory.openSession();
      Transaction tx = session.beginTransaction();
      Employee emp = new Employee();
      emp.setName("Teja");
      emp.setAddress("Bengaluru");
      session.persist(emp);
        tx.commit();
        session.close();
        sessionFactory.close();
        System.out.println("Employee details saved succeussfully...");
        
    }
    
}


UpdateData.java
===============

package mypack;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;


public class UpdateData {
     static SessionFactory sessionFactory;

    public static void main(String[] args) {
      sessionFactory = new Configuration().configure().buildSessionFactory();
      Session session = sessionFactory.openSession();
      Transaction tx = session.beginTransaction();
      Employee emp = (Employee)session.load(Employee.class, 1);
      emp.setAddress("AP");
      
      session.persist(emp);
       // dirty checking.
        tx.commit();
        session.close();
        sessionFactory.close();
        System.out.println("Employee details saved succeussfully...");
    }
}