Strategy

import java.util.*;
enum TransportMode{
    CAR,
    BIKE,
    WALK
}
//-----------------------------------------
interface PathStrategy{
    public void calculatePath(String from, String to);
}

class CarPathStrategy implements PathStrategy{
    public void calculatePath(String from, String to){
        System.out.println("Finding path by car");
    }
}
class BikePathStrategy implements PathStrategy{
    public void calculatePath(String from, String to){
        System.out.println("Finding path by bike");
    }
}
class WalkPathStrategy implements PathStrategy{
    public void calculatePath(String from, String to){
        System.out.println("Finding path by Walk");
    }
}
//-----------------------------------------
class PathRegistry{ //registry for storing objects
    Map<TransportMode, PathStrategy> paths = new HashMap<>();
    public void register(TransportMode mode, PathStrategy pathStrategy){
        paths.put(mode,pathStrategy);
    }
    public PathStrategy getRegister(TransportMode mode){
        return paths.get(mode);
    }
}
//----------------------------------------

class GoogleMaps{ //made for calling choosen registory mode
    //get the registry object
    PathRegistry pathRegistry;
    GoogleMaps(PathRegistry pathRegistry){ 
        this.pathRegistry = pathRegistry;
    }
    public void findPath(String from, String to, TransportMode mode){ //called calculatePath of choosen mode.
        pathRegistry.getRegister(mode).calculatePath(from,to);
    }
}
//---------------------------------------
public class Client{
    public static void main(String[] args){
        //make original object
        PathStrategy car = new CarPathStrategy();
        PathStrategy bike = new BikePathStrategy();
        PathStrategy walk = new WalkPathStrategy();
        //add the in registry
        PathRegistry pathRegistry = new PathRegistry();
        pathRegistry.register(TransportMode.CAR, car);
        pathRegistry.register(TransportMode.BIKE, bike);
        pathRegistry.register(TransportMode.WALK, walk);
        
        //Use google map class to get the path from one point to another using a mode;
        GoogleMaps googleMap = new GoogleMaps(pathRegistry);
        googleMap.findPath("Alwar","Delhi",TransportMode.WALK);
        
    }
}