Immutable class // Location Class- adventure game 이용

개념

https://codedragon.tistory.com/m/7930

https://limkydev.tistory.com/m/68 

 

inner code can't be changed once they are created.

To avoid external modification. // for encapsulation and reducing errors.

 

private/ final field

setter X

variables는 constructor에

HashMap(Key,value) 이용한 경우

 

Location Class

package com.timbuchalka;

import java.util.HashMap;
import java.util.Map;


public class Location {
    private final int locationNum;       //private final modifier aa;       V
    private final String description;
    private final Map<String, Integer> exits;
                                                                        //        V
    public Location(int locationNum, String description, Map<String, Integer> exits) {
        this.locationNum = locationNum;
        this.description = description;
        this.exits = new HashMap<String, Integer>(exits);   //add method(addExit)대신 Map.put이용하려고.
        this.exits.put("Q", 0);
    }

//    public void addExit(String direction, int location) {
//        exits.put(direction, location);
//    }

    public int getLocationNum() {
        return locationNum;
    }

    public String getDescription() {
        return description;
    }

    public Map<String, Integer> getExits() {
        return new HashMap<String, Integer>(exits);
    }
}

 

Main

package com.timbuchalka;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    private static Map<Integer, Location> locations = new HashMap<Integer, Location>();

    public static void main(String[] args) {

	    Scanner scanner = new Scanner(System.in);

//temExit(map.put)으로 값설정후, call constructor으로 tempExit 실행케 코딩           V

        //값설정 +방향 설정
        Map<String, Integer> tempExit = new HashMap<String, Integer>();
        locations.put(0, new Location(0, "You are sitting in front of a computer learning Java",tempExit));

        tempExit = new HashMap<String, Integer>();  // basic 방향공간 define
        tempExit.put("W", 2);
        tempExit.put("E", 3);
        tempExit.put("S", 4);
        tempExit.put("N", 5);
        locations.put(1, new Location(1, "You are standing at the end of a road before a small brick building",tempExit));

        tempExit = new HashMap<String, Integer>();
        tempExit.put("N", 5);
        locations.put(2, new Location(2, "You are at the top of a hill",tempExit));

        tempExit = new HashMap<String, Integer>();
        tempExit.put("W", 1);
        locations.put(3, new Location(3, "You are inside a building, a well house for a small spring",tempExit));

        tempExit = new HashMap<String, Integer>();
        tempExit.put("N", 1);
        tempExit.put("W", 2);
        locations.put(4, new Location(4, "You are in a valley beside a stream",tempExit));

        tempExit = new HashMap<String, Integer>();
        tempExit.put("S", 1);
        tempExit.put("W", 2);
        locations.put(5, new Location(5, "You are in the forest",tempExit));

        //문장을 한글자로 인식하도록 값설정
        Map<String, String> vocabulary = new HashMap<String, String>();
        vocabulary.put("QUIT", "Q");
        vocabulary.put("NORTH", "N");
        vocabulary.put("SOUTH", "S");
        vocabulary.put("WEST", "W");
        vocabulary.put("EAST", "E");

//출력코드
        int loc = 1;
        while(true) {
            System.out.println(locations.get(loc).getDescription());
            tempExit.remove("S");

            if(loc == 0) {
                break;
            }

            Map<String, Integer> exits = locations.get(loc).getExits();
            System.out.print("Available exits are ");
            for(String exit: exits.keySet()) {
                System.out.print(exit + ", ");
            }
            System.out.println();
//String console 입력
            String direction = scanner.nextLine().toUpperCase();

            if(direction.length() > 1) {        //입력이 문장이라면
                String[] words = direction.split(" ");
                for(String word: words) {
                    if(vocabulary.containsKey(word)) {
                        direction = vocabulary.get(word);
                        break;
                    }
                }
            }

            if(exits.containsKey(direction)) {
                loc = exits.get(direction);

            } else {
                System.out.println("You cannot go in that direction");
            }
        }

    }
}

//Output
D:\IT\JDK\jdk11.0.6_10\bin\java.exe "-javaagent:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\lib\idea_rt.jar=50044:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\bin" -Dfile.encoding=UTF-8 -classpath D:\IT\Java-Collections-Immutable-Classes-Source-code\out\production\Adventure com.timbuchalka.Main
You are standing at the end of a road before a small brick building
Available exits are Q, S, E, N, W, 
1
You cannot go in that direction
You are standing at the end of a road before a small brick building
Available exits are Q, S, E, N, W, 
west
You are at the top of a hill
Available exits are Q, N, 
q
You are sitting in front of a computer learning Java

Process finished with exit code 0