code: private Connection getConnectionFromDriverManager(String dbDriverClassName, String dbUrlStr,
                                                        String userName, String password, String propertiesString)
              throws SQLException
      {
  
          Connection con = null;
          try {
              Class.forName(dbDriverClassName);
              if (!EMPTY_STRING.equals(userName)) {
                  con = DriverManager.getConnection(dbUrlStr, userName, password);
              } else if (!EMPTY_STRING.equals(propertiesString)) {
                  Properties props = parseProperties(propertiesString);
                  if (props == null) {
                      throw new ControlException("Invalid properties annotation value: " + propertiesString);
                  }
                  con = DriverManager.getConnection(dbUrlStr, props);
              } else {
                  con = DriverManager.getConnection(dbUrlStr);
              }
          } catch (ClassNotFoundException e) {
              throw new ControlException("Database driver class not found!", e);
          }
          return con;
      }
docs: Get a JDBC connection from the DriverManager.
  
  @param dbDriverClassName Specified in the subclasse's ConnectionDriver annotation.
  @param dbUrlStr          Specified in the subclasse's ConnectionDriver annotation.
  @param userName          Specified in the subclasse's ConnectionDriver annotation.
  @param password          Specified in the subclasse's ConnectionDriver annotation.
  @return null if a connection cannot be established.
  @throws SQLException