问一种文本冒险游戏战斗系统的方法

EN

 public class Combat{

    //enemy variables
    private int enemyHealth = (int) (Math.random()*75);
    private int maxEnemyDamage = 25;
    private String enemyName;
    //player variables
    private int playerHealth = 100;
    private int playerDamage = 50;
    //health potion variables
    private int numHealthPotions = 3;
    private int healAmount = 30;
    private int dropChance = 50; //percentage

    public String getEnemyName() {
        String[] enemy = {"Zombie", "Witch", "Hell Dog", "Skeleton"};
        int i = (int) (Math.random() * 4);
        this.enemyName = enemy[i];
        return this.enemyName;
    }
    public int getEnemyHealth(){
        return enemyHealth;
    }
    public void enemyAppears(){
        String enemy = getEnemyName();
        System.out.println("A " + enemy + " has appeared with " + enemyHealth + " health.");
    }
    public void attack() {
        int damageTaken =(int) (Math.random() * maxEnemyDamage);
        int damageDealt =(int) (Math.random() * playerDamage);
        enemyHealth -= damageDealt - getEnemyHealth();
        playerHealth -= damageTaken;
        System.out.println("You strike for " + damageDealt);
        System.out.println("You have been hit for " + damageTaken);
        System.out.println("You have " + playerHealth + " hp left.\n The enemy has " + enemyHealth + " hp left.");
        if (playerHealth < 0){
            System.out.println("You died.");
            System.exit(15);
        }

 Combat combat = new Combat();
    Scanner input = new Scanner(System.in);
    System.out.println("Welcome to the dungeon");
    boolean running = true;
    GAME:
    while(running){

        combat.enemyAppears();

        System.out.println("Choose:\n1. To Attack \n2. To Heal \n3. To Run");
        String choice = input.next();
        if(choice.equals("1")) {
            combat.attack();
        } else if (choice.equals("2")){
            combat.heal();
        } else {
            combat.run();
            break;
        }
    }
}