public Object getDB1and2Data()
  throws HibernateException {
    Session     sess = null;
    Transaction tran = null;

    try {
      sess = GblUtils.getDB1Session();
      tran = sess.beginTransaction();
      try {
        // ... here I get some data from DB1

        // and then some from DB2
        Object obj = getDB2Data(obj1);

        tran.commit();
      }
      catch (HibernateException x) {
        if (tran!=null) tran.rollback();
        throw x;
      }
      finally {sess.close();}
    }
    catch (HibernateException x) {
      x.printStackTrace();
      throw x;
    }
    return ...;
  }

  public Object getDB2Data(Object par)
  throws HibernateException {
    Session     sess  = GblUtils.getDB2Session();
    Transaction tran  = sess.beginTransaction();

    try {
      // ... here I get the data from DB2
      tran.commit();
    }
    catch (HibernateException x) {
      if (tran!=null) tran.rollback();
      throw x;
    }
    finally {sess.close();}
    return ...;
  }