What is the best way to duplicate / extend functions of a static class?

Question

In the application I'm working in, there is one class that supports connecting to the database. All members of this class are static to provide a singleton pattern, so the actual connection logic is executed in a static initialization block:

public class HibernateUtil {

    private static final SessionFactory sessionFactory;

    static {
        sessionFactory = new Configuration().configure().buildSessionFactory();
    }

    static void openSession() {
        //open session with sessionFactory
    }

    public static Session currentSession() {
        //return the currently open session
    }

    static void closeSession() {
        //close the currently open session
    }

}

However, the application should now open a database connection to the second database. Now that this class is structured, the only way to save the second connection by saving the above template is to create a second class (something like SecondHibernateUtil) and change one configuration line in the initializer block. It looks like a really wasteful amount of copies / paste.

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  // Create a new utility class using a map instead.
  class HibernateUtility { 
  
      private Map<String, SessionFactory> factories;
      private HibernateUtility instance;
  
      public  static HibernateUtility getInstance() { 
          if( instance == null ) { 
          instance = new HibernateUtility();
          }
          return instance;
      }
  
      private HibernateUtility() {}
  
      private void check( String whichConnection ) { 
          if( !factories.containsKey( whichConnection ) ) {
              // start the connection
              factories.put( whichConnection, new Configu..
              //... etc etc ().configure().buildSessionFactory() );
          }
      }
  
      void openSession( String whichConnection ) {
          check( whichConnection );
          //open session with sessionFactory
          factories.get( whichConnection ).open(); //etcetc
      }
  
      Session currentSession( whichConnection ) {
          check( whichConnection );
          //return the currently open session
          factories.get( whichConnection ) .....
      }
  
      void closeSession( String whichConnection ) {
          check( whichConnection );
          //close the currently open session
          factories.get( whichConnection );
      }       
  }
  
  //------------------------------------------
  // Make your existing class call that class
  public class HibernateUtil {
  
      static void openSession() {
          //open session with sessionFactory
          HibernateUtility.getInstance( "one" ).openSession();
      }
  
      public static Session currentSession() {
          //return the currently open session
          HibernateUtility.getInstance( "one" ).currentSession();
      }
  
      static void closeSession() {
          //close the currently open session
          HibernateUtility.getInstance( "one" ).closeSession();
      }
  }
  
  //------------------------------------------            
  // Make the new connection use that class too.
  public class HibernateUtil {
  
      static void openSession() {
          //open session with sessionFactory
          HibernateUtility.getInstance( "two" ).openSession();
      }
  
      public static Session currentSession() {
          //return the currently open session
          HibernateUtility.getInstance( "two" ).currentSession();
      }
  
      static void closeSession() {
          //close the currently open session
          HibernateUtility.getInstance( "two" ).closeSession();
      }
  }
  

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