The program assumes that we have a 'Route' class available, with the following 'get' methods needed for the task:
- getDirection(), which returns the direction of the route. 
  The return value is an enum of type 'CardinalDirection', with four possible values (NORTH, SOUTH, EAST, and WEST).
- getLength(), which returns the route's length as a floating-point number.




Write a class 'method'
public static void printNorthRoutes(ArrayList<Route> routes)

which receives a list of Route objects as a parameter. 
The method prints all the routes whose direction is north. 
Use the Route class's toString method for printing.





import java.util.Random;
import java.util.ArrayList;
import java.util.Collections;

public class Test{
    public static void main(String[] args){
        final Random r = new Random();
        
     
        ArrayList<Route> routes = new ArrayList<>();
        // r.nextInt(3) => from 0 (incl) to 3 (excl)
        int m = r.nextInt(3) + 2;
        for (int i = 0; i < m; i++) {
            routes.add(new Route(r.nextInt(100), CardinalDirection.NORTH));
        }
        
        m = r.nextInt(5) + 5;
        CardinalDirection[] nonNorth = {CardinalDirection.SOUTH, CardinalDirection.EAST, CardinalDirection.WEST};
        for (int i = 0; i < m; i++) {
            routes.add(new Route(r.nextInt(100), nonNorth[r.nextInt(3)]));
        }
        
        Collections.shuffle(routes, r);
        
        System.out.println("All routes:");
        routes.stream().forEach(re -> System.out.println(re));
        
        System.out.println("North routes:");
        printNorthRoutes(routes);
       
    }


    //ADD
    public static void printNorthRoutes(ArrayList<Route> routes) {
         // print
         routes.stream().filter(route -> route.getDirection() == CardinalDirection.NORTH).forEach(route -> System.out.println(route));
         // store in a new ArrayList
         // ArrayList<Route> northRoutes = routes.stream().filter(route -> route.getDirection() == CardinalDirection.NORTH).collect(Collectors.toCollection(ArrayList::new));
         // return northRoutes;
    }






}








class Route {
    private double length;
    private CardinalDirection direction;
    
    public Route(double length, CardinalDirection direction) {
        this.length = length;
        this.direction = direction;
    }




    public double getLength() {
        return length;
    }

    public void setLength(double length) {
        this.length = length;
    }




    public CardinalDirection getDirection() {
        return direction;
    }

    public void setDirection(CardinalDirection direction) {
        this.direction = direction;
    } 



    
    public String toString() {
        return "Direction: " + direction + ", length: " + length;
    }
}



enum CardinalDirection {
    NORTH, SOUTH, EAST, WEST
}











All routes:
Direction: SOUTH, length: 16.0
Direction: NORTH, length: 77.0
Direction: NORTH, length: 95.0
Direction: WEST, length: 7.0
Direction: SOUTH, length: 33.0
Direction: NORTH, length: 96.0
Direction: WEST, length: 90.0
Direction: SOUTH, length: 29.0
Direction: SOUTH, length: 10.0
Direction: WEST, length: 7.0
Direction: EAST, length: 7.0
Direction: WEST, length: 79.0
Direction: NORTH, length: 19.0


North routes:
Direction: NORTH, length: 77.0
Direction: NORTH, length: 95.0
Direction: NORTH, length: 96.0
Direction: NORTH, length: 19.0