文本类Java游戏代码执行中断求助：无法正常进入山区场景

问题根源 #

问题出在Scanner的输入处理逻辑上：nextInt()方法仅读取输入的整数部分，不会处理用户输入数字后按下的换行符。当猜数字游戏结束后，后续调用nextLine()时，会直接读取缓冲区中残留的换行符，导致input为空字符串，触发山区路径选择环节的default分支，直接输出无效输入提示。

修复方案 #

在playRandomNumberGuesser方法的循环结束后，添加一行userInput.nextLine()，清除输入缓冲区中残留的换行符，确保后续的nextLine()能正确等待用户输入。

修改后的playRandomNumberGuesser方法 #

public static void playRandomNumberGuesser(int min, int max, Scanner userInput) {
    Random random = new Random();
    int randomNumber = random.nextInt((max - min) + 1) + min;
    int guess;
    boolean guessedCorrectly = false;

    do {
        System.out.print("Enter your guess (" + min + "-" + max + "): ");
        guess = userInput.nextInt();

        if (guess < min || guess > max) {
            System.out.println("Please enter a number between " + min + " and " + max + ".");
        } else if (guess < randomNumber) {
            System.out.println("Too low. Try again.");
        } else if (guess > randomNumber) {
            System.out.println("Too high. Try again.");
        } else if (guess == randomNumber) {
            System.out.println("[OLD MAN] 'Well done!! you've done well'\n"
                    + "[OLD MAN] 'You really do have a knack for these games. I'll tell you that. Here, take this for your journey.'\n");
            guessedCorrectly = true;
        }
    } while (!guessedCorrectly);
    
    // 清除输入缓冲区中的残留换行符
    userInput.nextLine();
}

补充优化方案 #

如果后续还有混合使用nextInt()和nextLine()的场景，也可以统一用nextLine()读取所有输入，再将需要转为数字的内容用Integer.parseInt()转换，从根源避免换行符残留问题，示例如下：

// 替换原有的guess = userInput.nextInt();
String guessStr = userInput.nextLine();
try {
    guess = Integer.parseInt(guessStr);
} catch (NumberFormatException e) {
    System.out.println("Please enter a valid number.");
    continue;
}

内容的提问来源于stack exchange，提问作者al.erceg