java - 在这种情况下如何防止方法运行两次？

Question

这是我的代码的简化版本:

Thread t = new Thread() {
    Scanner user = new Scanner(System.in);
    public void run() {
        setDistance();
    }

    void setDistance() {
        System.out.print("Set distance.");
        int distance = user.nextInt();
        if (distance < ableJump) {
            jump(); 
        } else { // if you are too weak to jump that far
            System.out.print("Too far!");
            setDistance();
        }
        // after that:
        if (player == 1) {
            player = 2; // sets to 2 if it was player 1's turn
        } else if (player == 2) {
            player = 1; // sets to 1 if it was player 2's turn
        }
        System.out.printf("Player %d's turn", player);
        /* now a method runs the threads again
         * and the cycle continues..
         */
    }
};

如果用户设置的距离太大，从而触发“太远”else 语句并再次调用该方法，用户将获得新的机会将距离设置为一个值。

但是问题是:setDistance()结束后，它又回到了它被调用的点，这个点也在setDistance()中，并从那里继续运行。这意味着 setDistance() 方法运行了两次，因此 player 变量切换回其原始状态。而且永远不会轮到玩家 2!

有没有其他方法可以做到这一点但得到相同的结果。

Answer 1

尝试花一段时间来做这件事，而不是记忆你的函数。

void setDistance() {
    int distance;
    while (true) {
        System.out.print("Set distance.");
        distance = user.nextInt();
        if (distance < ableJump) {
            break;
        }
        System.out.print("Too far!");
    }
    jump(); 
    // after that:
    player = 3 - player;
    System.out.printf("Player %d's turn", player);
}