DBconnector.java

public class DBconnector {

    private Connection connection;
    private static DBconnector dBconnector;

    private DBconnector() {

      try {

           DriverManager.registerDriver(new Driver());
           this.connection = DriverManager.getConnection(
                   String.format("jdbc:mysql://%s:%s","localhost", "3306","user","123"));

          dbInit();

      } catch (SQLException  d) {
                d.printStackTrace();
            }
        }


    private void dbInit(){

        try(Statement statement = this.connection.createStatement()){
            statement.execute("CREATE SCHEMA IF NOT EXISTS web_app");
            statement.execute("USE web_app");
            statement.execute("CREATE TABLE IF NOT EXISTS visitors (id int(5) NOT NULL AUTO_INCREMENT, " +
                    "address varchar(30), rm_host varchar(30), rm_port varchar (8)," +
                    " method varchar(10), user_agent varchar(500),  visit_timestamp timestamp, PRIMARY KEY (id)," +
                    " UNIQUE KEY address_UNIQUE (address))DEFAULT CHARSET=utf8");}
        catch (SQLException e){
            e.printStackTrace();
        }
    }

        public static DBconnector getInstance() {
            if (dBconnector == null)
                dBconnector = new DBconnector();
            return dBconnector;
        }

        public Connection getConnection() {
            return connection;
        }
    }