NullPointer in SQLDAO

package daos;

import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import model.Route;
import model.RouteStage;

public class SQLDAO extends DAO {
    static private String userName = "root";
   static private String password = "";
   static private String url =
                  "jdbc:mysql://localhost:8080/routes";
   static private Connection connection = null;
   static private Statement stmt = null;
   static private ResultSet rs = null;
   public SQLDAO() {
       try{
            connection = DriverManager.getConnection(url,userName,password);
            stmt = connection.createStatement();
       }catch (SQLException e){
            System.out.println(e.getMessage());       }

}




    @Override
    public List<Route> getRoutes(){
        List<Route> routes = new ArrayList<>();
        try{
            String query = "CALL GetRoutes()";
            rs = stmt.executeQuery(query);
            while(rs.next()){
                int id = rs.getInt("ROUTEID");
                String routeTitle = rs.getString("ROUTETITLE");
                String departurePoint = rs.getString("DEPARTUREPOINT");
                Route route = new Route(id,routeTitle,departurePoint);


                List<RouteStage> stages = new ArrayList<>();
                String query2 = "CALL GetRouteStages( "+ id+" )";
                Statement stmt2 = connection.createStatement();
                ResultSet rs2 = stmt2.executeQuery(query2);
                while(rs2.next()){

                    int stageNumber = rs2.getInt("STAGENUMBER");
                    String endPoint = rs.getString("ENDPOINT");
                    float stageLength = rs2.getFloat("STAGELENGTH");
                    int routeId = rs2.getInt("ROUTEID");

                    RouteStage stage = new RouteStage(stageNumber, endPoint, stageLength,routeId);
                    stages.add(stage);

                }
                route.setRouteStages(stages);
                routes.add(route);
            }
        }catch(SQLException e){
            System.out.println(e);

        }
        return routes;

    }

    @Override
    public void addRoute(Route route) {
        // TODO Auto-generated method stub

    }

    @Override
    public void addStage(RouteStage stage) {
        // TODO Auto-generated method stub

    }

    @Override
    public Route getRoute(int routeId) {
        // TODO Auto-generated method stub
        return null;
    }





}