构造函数-找不到符号

Question

I am trying to compile a program, which has a subclass DramaticGame , of Game. The subclass contains the following:

public class DramaticGame extends Game
{
  public DramaticGame(String machineName, int machineSize, String rackName, int rackSize)
  {
    super.makeMachine(machineName, machineSize);
    super.makeRack(rackName, rackSize);
  }
}

DramaticGame.java:5: cannot find symbol

symbol : constructor Game()

location: class Game

{

^

It says it cannot find the "{" symbol in Game, but i am not sure how to fix this.

public Game(String paramString1, int paramInt1, String paramString2, int paramInt2)
{
  this.machine = makeMachine(paramString1, paramInt1);
  this.rack = makeRack(paramString2, paramInt2);
}

Answer 1

Your superclass is missing default constructor which is invoked implicitly if you do not issue

super(eventual params);

as first statement in your constructor.

Answer 2

No, what it can't find is a default constructor.

The compiler will create a no-argument default constructor if you don't supply any constructors.

But the moment you write one you're on your own.

I'd advise that you write one that calls the one you've already written with default arguments:

public class DramaticGame extends Game
{
  public DramaticGame() {
      this("default-machine-name", 1024, "default-rack-name", 10); 
  }

  public DramaticGame(String machineName, int machineSize, String rackName, int rackSize)
  {
    super.makeMachine(machineName, machineSize);
    super.makeRack(rackName, rackSize);
  }
}

I'd also wonder if your Game constructor should take rack name and size. The fact that those are members of the Game class suggests to me that they should be set in the Game constructor.