public static void main(String[] args) {
    Class.forName("org.hsqldb.jdbcDriver").newInstance();
        // start persistence
       
        final EntityManagerFactory factory = Persistence.createEntityManagerFactory("gse");
        final EntityManager manager = factory.createEntityManager();

}

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
   version="1.0">

    <!-- external database setup -->
    <!--
   <persistence-unit name="sample" transaction-type="RESOURCE_LOCAL">
       <class>addressbook.Person</class>
      <properties>
         <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
         <property name="hibernate.connection.username" value="sa"/>
         <property name="hibernate.connection.password" value=""/>
         <property name="hibernate.connection.url" value="jdbc:hsqldb:hsql://localhost"/>
         <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
         <property name="hibernate.hbm2ddl.auto" value="update"/>         
      </properties>
   </persistence-unit>
    -->
   
   <!-- in-process database setup -->
   <persistence-unit name="gse" transaction-type="RESOURCE_LOCAL">
       <class>de.informus.gse.data.Area</class>
       <class>de.informus.gse.data.Category</class>
       <class>de.informus.gse.data.File</class>
       <class>de.informus.gse.data.MapMarker</class>
       <class>de.informus.gse.data.Metadata</class>
       <class>de.informus.gse.data.PointOfContact</class>
       <class>de.informus.gse.data.PolicyDriver</class>
       <class>de.informus.gse.data.Product</class>
       <class>de.informus.gse.data.ProductType</class>
       <class>de.informus.gse.data.Quicklook</class>
       <class>de.informus.gse.data.Resource</class>
       <class>de.informus.gse.data.ServiceActor</class>
       <class>de.informus.gse.data.ServiceCase</class>
       <class>de.informus.gse.data.ServiceProvider</class>
       <class>de.informus.gse.data.ServiceType</class>
       <class>de.informus.gse.data.ServiceUser</class>
       <class>de.informus.gse.data.Time</class>
       <properties>
         <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
         <property name="hibernate.connection.username" value="sa"/>
         <property name="hibernate.connection.password" value=""/>
         <property name="hibernate.connection.url" value="jdbc:hsqldb:GsefmDB"/>
         <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
         <property name="hibernate.hbm2ddl.auto" value="update"/>         
      </properties>
   </persistence-unit>
</persistence>