我无法将 (String-) 值传递给另一个 class 的 setter 方法

Question

我知道我还没有写catch块。（原因？，但我认为这实际上不是问题； "Game" class的属性是完全可变的）

当我尝试调用 Player 中的 setName 方法时，我总是得到 IOException（即使我将 Player 中的 "name" 设置为 public 并直接更改它）。

    public class game{



    protected static int amountPlayers;
    protected static Player[] playerList = new Player[amountPlayers];

public static void main (String[] args) throws IOException{
        //Scanner reader = new Scanner(System.in);
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        String input;

        System.out.println("new round? (1 for yes; enter for no):");
        int boo = Integer.parseInt(br.readLine());

        if (boo == 1) {
          Rounds.setNew(true);
        } // end of if

        if (Rounds.getNew() == true) {
          //SavingManagement.createFile();                            
          System.out.println("# of players:");
          int amount = Integer.parseInt(br.readLine());
          setAmountPlayers(amount);
        } // end of if

        for (int i = 0; i < amountPlayers; i++) {
          System.out.println("Name player No. " + (i + 1) + ":");
          input = br.readLine();
          playerList[i].setName(input);      
        } // end of for
        }


    public class Player {


      protected static int score;     
      protected static String name = "";



      public static void setName(String input) {
        name = input;
      }
    }

Answer 1

PlayerList 包含 Player 对象，因此当您像这样调用 setName 方法时： playerList[i].setName(input) 它是通过 class Player 的一个实例，但是方法实际上是静态的，应该这样调用：

Player.setName()

尽管如此，您可以做的最好的事情是在 class Player 中添加一个构造函数，在数组 playerList 中添加新的 Player 对象并创建方法 setName() class Player 中的其他变量是非静态的。

Answer 2

您需要播放器 class 作为 public 内部 class 吗？您需要保护乐谱和名称吗？

否则这应该有效：

public class game {

    protected static int amountPlayers;
    protected static Player[] playerList = new Player[amountPlayers];

    public static void main(String[] args) throws IOException {
        for (int i = 0; i < amountPlayers; i++) {
            playerList[i].setName("test");
        }
    }
}

class Player {
    private int score;
    private String name = "";

    public void setName(String input) {
        name = input;
    }
}

Answer 3

假设您在 amountPlayers 中提供了有效大小，通过编写以下语句，您只是在创建播放器数组而不是对其进行初始化。

protected static int amountPlayers = 100;

/* This will just create the array */
protected static Player[] playerList = new Player[amountPlayers];

在使用 setName() 之前，您必须按如下方式初始化数组：

for(int x = 0; x < amountPlayers; x++) {
    playerList[x] = new Player();
}

或者你可以这样做：

/* Create a new object of class Player */
Player myPlayer = new Player();

/* Set Name */ 
myPlayer.setName(input); 

/* Assign it to your array */
playerList[i] = myPlayer;

我无法将 (String-) 值传递给另一个 class 的 setter 方法

I cannot pass a (String-)value to another class's setter method

java

setter

attributes