超类中没有可用的构造函数（Java）

Question

I have one super class, which called game that. It looks like this:

import java.util.ArrayList;

public class Game {
    private ArrayList<Enemy> enemies = new ArrayList<Enemy>();
    private ArrayList<Tower> towers = new ArrayList<Tower>();
    private int corridorLength;
    private int currentPosition = 0;
    public Game(int corridorLength){
        this.corridorLength = corridorLength;
    }

    public void addTower(int damage,int timeStep){
        this.towers.add(new Tower(damage,timeStep)); // Add tower with 
current position corrdor length

    }
    public void addEnemy(int health, int speed){
        this.enemies.add(new Enemy(health,speed));
    }
    public void advance(){
        this.currentPosition = this.currentPosition + 1;
        if(this.currentPosition == this.corridorLength){
            System.out.println("Game Over");
        }
    }
    public void printDamage(){
        System.out.println(this.towers.get(this.currentPosition));
    }

}

The main focus is on the public void addTower(int, int) So, I have a subclass called Tower:

public class Tower extends Game {

   public Tower(int damage, int timeStep){
       super.addTower(damage,timeStep);
   }
   public void getDamage(){
       super.printDamage();
   }
}

And subclass of the Tower subclass called Catapult:

public class Catapult extends Tower {
    public Catapult(){
        super(5,3);
    }

}

I am new to Java and can't see what am I doing wrong here. Why do I need a default constructor for the Tower in the Game?

Answer 1

You need to explicitly declare default constructor in Game class.

public Game (){} 

Since, Object instantiation chained to Object class during that, it will call its super class constructor. You have explicitly declared arg-constructor in Game , so default constructor won't be added automatically.