The Connection.createStatement() return a statement even if the connection is closed.
It should give an error when try to get a statement on close connection.

Below sample code:

Properties props = new Properties();
props.put("user", "test1");
props.put("password", "test1");
Connection connection = java.sql.DriverManager.getConnection("jdbc:mariadb://192.168.53.30:3306/test1", props);

Statement st1 = connection.createStatement();
connection.close();
Statement st2 = connection.createStatement(); // error here ???