package com.mycompany;

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

public class HibernateUtil {

private static final SessionFactory sessionFactory = buildSessionFactory();

//@SuppressWarnings("deprecation")
private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
return (SessionFactory) new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}


public static SessionFactory getSessionFactory() {
return sessionFactory;
}

public static void shutdown() {
// Close caches and connection pools
getSessionFactory().close();
}

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configurat.."> 
<hibernate-configuration>
 <session-factory>
  <property name="hibernate.connection.driver_class">org.h2.Driver</property>
  <property name="hibernate.connection.password"></property>
  <property name="hibernate.connection.url">jdbc:h2:mem:sample</property>
  <property name="hibernate.connection.username">sa</property>
  <property name="hibernate.default_schema">online_shop</property>
  <property name="hibernate.dialect">org.hibernate.dialect.H2Dialect</property>
  <property name="hibernate.show_sql">true</property>
   <!— JDBC connection pool (use the built-in) —>
<property name="connection.pool_size">1</property>
<!— Disable the second-level cache —>
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
<!— Enable Hibernate's automatic session context management —>
<property name="hibernate.current_session_context_class">thread</property>
<!— Drop and re-create the database schema on startup —>
<property name="hbm2ddl.auto">create</property>
 
 <mapping resource="User.hbm.xml" /> 
 <mapping resource="Order.hbm.xml" /> 
<!--<mapping class="com.mycompany.User" />-->
<!--<mapping class="com.mycompany.Order" />-->

 </session-factory>
</hibernate-configuration>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 
<hibernate-mapping>
    <class name="com.mycompany.User" table="USERS">
        <id name="id" type="int">
            <column name="ID" />
            <generator class="identity" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="NAME" length="20" not-null="true" unique="true"/>
        </property>
<!--        <set name="orders" table="ORDERS" inverse="true" lazy="true" fetch="select"> -->
<!--             <key> -->
<!--                 <column name="ID" not-null="true" /> -->
<!--             </key> -->
<!--             <one-to-many class="com.mycompany.Order" /> -->
<!--         </set> -->
    </class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 
<hibernate-mapping>
    <class name="com.mycompany.Order" table="ORDERS">
        <id name="id" type="int">
            <column name="ID" />
            <generator class="identity" />
        </id>
       
        <property name="id_user" type="int">
            <column name="ID_USER" />
        </property>
       
        <property name="item" type="java.lang.String">
            <column name="ITEM" />
        </property>
       
    </class>
</hibernate-mapping>