我自己是个菜鸟，但我希望这能有所帮助。你可以试着在while循环之前设置一个布尔标志，当玩家（如果你可以这么叫他们，那就只有你了）选择一个给定的选项时，值会改变（F-〉T，反之亦然），它会退出循环。类似于：

boolean isObjectChosen = false;
while (!isObjectChosen) {
    if (Objects.equals(armourType, "D")) {
        System.out.println("Very nice, diamond is much stronger!");
        isObjectChosen = true;
    } else if (Objects.equals(armourType, "W")) {
        System.out.println("That wouldn't have been my choice, but very well.");
        isObjectChosen = true;
    }else {
        System.out.println("You didn't choose one of the options!");
    }

看起来有人发布了一个while循环答案。下面是一个递归替代方法：

public static void main(String[] args)
{
    Scanner input = new Scanner(System.in);
    System.out.println("Hello Sir! Would you like to have diamond or wooden armour for your journey?");
    getValidArmour(input);
    input.close();
}
private static void getValidArmour(Scanner input)
{
    System.out.print("Type D for Diamond or W for Wooden: ");
    String armourType = input.nextLine();
    switch (armourType)
    {
        case "D" -> System.out.println("Very nice, diamond is much stronger!");
        case "W" -> System.out.println("That wouldn't have been my choice, but very well.");
        default ->
        {
            System.out.println("You didn't choose one of the options!");
            getValidArmour(input);
        }
    };
}