I'm writing a simple text based RPG in java. I think its a good exercise to practice OO and think about how objects should best interact. Here is the code, I'd be interested to hear any thoughts!

The game class contains a single game:

Here's a simple Dungeon class, a collection of Rooms laid out in map. The player moves from room to room encountering and battling monsters.

Here's the monster class

Battle class

Room class

And the player class

public final class Player {

    private final String name;
    private final String description;
    private final int maxHitPoints;
    private int hitPoints;
    private int numPotions;
    private final int minDamage;
    private final int maxDamage;
    private final Random random = new Random();

    private Player(String name, String description, int maxHitPoints, int minDamage, int maxDamage,
            int numPotions) {
        this.name = name;
        this.description = description;
        this.maxHitPoints = maxHitPoints;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.numPotions = numPotions;
        this.hitPoints = maxHitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Monster monster) {
        int attackStrength = monster.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  " + name + " is hit for %d HP of damage (%s)\n", attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + name + " has been defeated");
        }
    }

    public void heal() {
        if (numPotions > 0) {
            hitPoints = Math.min(maxHitPoints, hitPoints + 20);
            System.out.printf("  %s drinks healing potion (%s, %d potions left)\n", name,
                    getStatus(), --numPotions);
        } else {
            System.out.println("  You've exhausted your potion supply!");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

    public String getStatus() {
        return "Player HP: " + hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public static Player newInstance() {
        return new Player("Mighty Thor",
                "a musclebound hulk intent on crushing all evil in his way", 40, 6, 20, 10);
    }
 
}

Thanks!!

I'm writing a simple text-based RPG in Java. I think it's a good exercise to practice OO and think about how objects should best interact. I'd be interested in hearing any thoughts!

The Game class contains a single game:

Here's a simple Dungeon class, a collection of Rooms laid out in the map. The player moves from room to room, encountering and battling monsters.

Here's the Monster class:

Battle class:

Room class:

And the Player class:

public final class Player {

    private final String name;
    private final String description;
    private final int maxHitPoints;
    private int hitPoints;
    private int numPotions;
    private final int minDamage;
    private final int maxDamage;
    private final Random random = new Random();

    private Player(String name, String description, int maxHitPoints, int minDamage, int maxDamage,
            int numPotions) {
        this.name = name;
        this.description = description;
        this.maxHitPoints = maxHitPoints;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.numPotions = numPotions;
        this.hitPoints = maxHitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Monster monster) {
        int attackStrength = monster.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  " + name + " is hit for %d HP of damage (%s)\n", attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + name + " has been defeated");
        }
    }

    public void heal() {
        if (numPotions > 0) {
            hitPoints = Math.min(maxHitPoints, hitPoints + 20);
            System.out.printf("  %s drinks healing potion (%s, %d potions left)\n", name,
                    getStatus(), --numPotions);
        } else {
            System.out.println("  You've exhausted your potion supply!");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

    public String getStatus() {
        return "Player HP: " + hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public static Player newInstance() {
        return new Player("Mighty Thor",
                "a musclebound hulk intent on crushing all evil in his way", 40, 6, 20, 10);
    }
}

public final class Monster {

    private final String name;
    private final String description;
    private int hitPoints;
    private final int minDamage;
    private final int maxDamage;
    private final static Random random = new Random();
    private final static Set<Integer> monstersSeen = new HashSet<Integer>();
    private final static int NUM_MONSTERS = 3;

    public static Monster newRandomInstance() {
        if (monstersSeen.size() == NUM_MONSTERS) {
            monstersSeen.clear();
        }
        int i;
        do {
            i = random.nextInt(NUM_MONSTERS);
        } while (monstersSeen.contains(i));
        monstersSeen.add(i);

        if (i == 0) {
            return new Monster("Harpy", Art.HARPY, 40, 8, 12);
        } else if (i == 1) {
            return new Monster("Gargoyle", Art.GARGOYLE, 26, 4, 6);
        } else {
            return new Monster("Hobgoblin", Art.HOBGOBLIN, 18, 1, 2);
        }
    }

    public static Monster newBossInstance() {
        return new Monster("Dragon", Art.DRAGON, 60, 10, 20);
    }

    private Monster(String name, String description, int hitPoints, int minDamage, int maxDamage) {
        this.name = name;
        this.description = description;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.hitPoints = hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public String getStatus() {
        return "Monster HP: " + hitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Player player) {
        int attackStrength = player.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  %s hits %s for %d HP of damage (%s)\n", player, this, attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + player + " transforms the skull of " + this
                    + " into a red pancake with his stone hammer");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

}

public final class Room {

    private final String description;
    private final Monster monster;
    private final Boolean isBossRoom;
    private final static Random random = new Random();
    private final static Set<Integer> roomsSeen = new HashSet<Integer>();
    private final static int NUM_ROOMS = 7;

    private Room(String description, Monster monster, Boolean isBossRoom) {
        this.description = description;
        this.monster = monster;
        this.isBossRoom = isBossRoom;
    }

    public static Room newRegularInstance() {
        if (roomsSeen.size() == NUM_ROOMS) {
            roomsSeen.clear();
        }
        int i;
        do {
            i = random.nextInt(NUM_ROOMS);
        } while (roomsSeen.contains(i));
        roomsSeen.add(i);

        String roomDescription = null;
        if (i == 0) {
            roomDescription = "a fetid, dank room teeming with foul beasts";
        } else if (i == 1) {
            roomDescription = "an endless mountain range where eagles saw looking for prey";
        } else if (i == 2) {
            roomDescription = "a murky swamp with a foul smelling odour";
        } else if (i == 3) {
            roomDescription = "a volcano with rivers of lava at all sides";
        } else if (i == 4) {
            roomDescription =
                    "a thick forest where strange voices call out from the trees high above";
        } else if (i == 5) {
            roomDescription =
                    "an old abandoned sailing ship, litered with the remains of some unlucky sailors";
        } else if (i == 6) {
            roomDescription = "a cafe filled with hipster baristas who refuse to use encapsulation";
        } else {
        }
        return new Room(roomDescription, Monster.newRandomInstance(), false);
    }

    public static Room newBossInstance() {
        return new Room("a huge cavern thick with the smell of sulfur", Monster.newBossInstance(),
                true);
    }

    public boolean isBossRoom() {
        return isBossRoom;
    }

    public boolean isComplete() {
        return !monster.isAlive();
    }

    @Override
    public String toString() {
        return description;
    }

    public void enter(Player player) throws IOException {
        System.out.println("You are in " + description);
        if (monster.isAlive()) {
            new Battle(player, monster);
        }
    }

}

public final class Player {

    private final String name;
    private final String description;
    private final int maxHitPoints;
    private int hitPoints;
    private int numPotions;
    private final int minDamage;
    private final int maxDamage;
    private final Random random = new Random();

    private Player(String name, String description, int maxHitPoints, int minDamage, int maxDamage,
            int numPotions) {
        this.name = name;
        this.description = description;
        this.maxHitPoints = maxHitPoints;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.numPotions = numPotions;
        this.hitPoints = maxHitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Monster monster) {
        int attackStrength = monster.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  " + name + " is hit for %d HP of damage (%s)\n", attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + name + " has been defeated");
        }
    }

    public void heal() {
        if (numPotions > 0) {
            hitPoints = Math.min(maxHitPoints, hitPoints + 20);
            System.out.printf("  " + name + " drinks healing potion (%s, %d potions left)\n",
                    getStatus(), --numPotions);
        } else {
            System.out.println("  You've exhausted your potion supply!");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

    public String getStatus() {
        return "Player HP: " + hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public static Player newInstance() {
        return new Player("Mighty Thor",
                "a musclebound hulk intent on crushing all evil in his way", 40, 6, 20, 10);
    }

}

public final class Monster {

    private final String name;
    private final String description;
    private int hitPoints;
    private final int minDamage;
    private final int maxDamage;
    private final static Random random = new Random();
    private final static Set<Integer> monstersSeen = new HashSet<Integer>();
    private final static int NUM_MONSTERS = 3;

    public static Monster newRandomInstance() {
        if (monstersSeen.size() == NUM_MONSTERS) {
            monstersSeen.clear();
        }
        int i;
        do {
            i = random.nextInt(NUM_MONSTERS);
        } while (monstersSeen.contains(i));
        monstersSeen.add(i);

        if (i == 0) {
            return new Monster("Harpy", Art.HARPY, 40, 8, 12);
        } else if (i == 1) {
            return new Monster("Gargoyle", Art.GARGOYLE, 26, 4, 6);
        } else {
            return new Monster("Hobgoblin", Art.HOBGOBLIN, 18, 1, 2);
        }
    }

    public static Monster newBossInstance() {
        return new Monster("Dragon", Art.DRAGON, 60, 10, 20);
    }

    private Monster(String name, String description, int hitPoints, int minDamage, int maxDamage) {
        this.name = name;
        this.description = description;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.hitPoints = hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public String getStatus() {
        return "Monster HP: " + hitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Player player) {
        int attackStrength = player.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  %s hits %s for %d HP of damage (%s)\n", player, name, attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + player + " transforms the skull of " + name
                    + " into a red pancake with his stone hammer");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

}

public final class Room {

    private final String description;
    private final Monster monster;
    private final Boolean isBossRoom;
    private final static Random random = new Random();
    private final static Set<Integer> roomsSeen = new HashSet<Integer>();
    private final static int NUM_ROOMS = 7;

    private Room(String description, Monster monster, Boolean isBossRoom) {
        this.description = description;
        this.monster = monster;
        this.isBossRoom = isBossRoom;
    }

    public static Room newRegularInstance() {
        if (roomsSeen.size() == NUM_ROOMS) {
            roomsSeen.clear();
        }
        int i;
        do {
            i = random.nextInt(NUM_ROOMS);
        } while (roomsSeen.contains(i));
        roomsSeen.add(i);

        String roomDescription = null;
        if (i == 0) {
            roomDescription = "a fetid, dank room teeming with foul beasts";
        } else if (i == 1) {
            roomDescription = "an endless mountain range where eagles soar looking for prey";
        } else if (i == 2) {
            roomDescription = "a murky swamp with a foul smelling odour";
        } else if (i == 3) {
            roomDescription = "a volcano with rivers of lava at all sides";
        } else if (i == 4) {
            roomDescription =
                    "a thick forest where strange voices call out from the trees high above";
        } else if (i == 5) {
            roomDescription =
                    "an old abandoned sailing ship, littered with the remains of some unlucky sailors";
        } else if (i == 6) {
            roomDescription = "a cafe filled with hipster baristas who refuse to use encapsulation";
        } else {
        }
        return new Room(roomDescription, Monster.newRandomInstance(), false);
    }

    public static Room newBossInstance() {
        return new Room("a huge cavern thick with the smell of sulfur", Monster.newBossInstance(),
                true);
    }

    public boolean isBossRoom() {
        return isBossRoom;
    }

    public boolean isComplete() {
        return !monster.isAlive();
    }

    @Override
    public String toString() {
        return description;
    }

    public void enter(Player player) throws IOException {
        System.out.println("You are in " + description);
        if (monster.isAlive()) {
            new Battle(player, monster);
        }
    }

}

public final class Player {

    private final String name;
    private final String description;
    private final int maxHitPoints;
    private int hitPoints;
    private int numPotions;
    private final int minDamage;
    private final int maxDamage;
    private final Random random = new Random();

    private Player(String name, String description, int maxHitPoints, int minDamage, int maxDamage,
            int numPotions) {
        this.name = name;
        this.description = description;
        this.maxHitPoints = maxHitPoints;
        this.minDamage = minDamage;
        this.maxDamage = maxDamage;
        this.numPotions = numPotions;
        this.hitPoints = maxHitPoints;
    }

    public int attack() {
        return random.nextInt(maxDamage - minDamage + 1) + minDamage;
    }

    public void defend(Monster monster) {
        int attackStrength = monster.attack();
        hitPoints = (hitPoints > attackStrength) ? hitPoints - attackStrength : 0;
        System.out.printf("  " + name + " is hit for %d HP of damage (%s)\n", attackStrength,
                getStatus());
        if (hitPoints == 0) {
            System.out.println("  " + name + " has been defeated");
        }
    }

    public void heal() {
        if (numPotions > 0) {
            hitPoints = Math.min(maxHitPoints, hitPoints + 20);
            System.out.printf("  %s drinks healing potion (%s, %d potions left)\n", name,
                    getStatus(), --numPotions);
        } else {
            System.out.println("  You've exhausted your potion supply!");
        }
    }

    public boolean isAlive() {
        return hitPoints > 0;
    }

    public String getStatus() {
        return "Player HP: " + hitPoints;
    }

    @Override
    public String toString() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    public static Player newInstance() {
        return new Player("Mighty Thor",
                "a musclebound hulk intent on crushing all evil in his way", 40, 6, 20, 10);
    }

}