扫描仪始终需要两个输入(Java)

时间:2019-03-24 16:23:21

标签: java java.util.scanner

我正在尝试实现一种方法,让玩家选择用户名。该方法根据当前运行的操作系统的用户名建议一个。现在,如果他/她对建议不满意,我想给用户一个更改其昵称的选项。现在的问题是,我总是不得不两次输入我的声明,因为我猜其中任何一个都不会被接受。

(例如,我必须输入:

“ y”

“ y”)

我尝试在while循环中更改语句(例如“ nameChange.hasNextLine()”)。我尝试添加“ nameChange.nextLine();”在“ line = nameChange.nextLine();”之前和之后(如关于SO的类似文章所建议),但均未奏效。

public class SetUsername implements Runnable {

    /**
     * Suggests a name based on the accessing OS's user Let's the user change the suggestion to his
     * or her own username.
     */
    @Override
    public void run() {
      String name = System.getProperty("user.name");
      Scanner nameChange = new Scanner(System.in);
      System.out.println("Your username is: " + name + ". Would you like to change it? (y/n)");
      String line;
      while (true) {
        line = nameChange.nextLine();
        if (line.equals("y")) {
          System.out.println("Chose a new username:");
          while(true) {
            name = nameChange.nextLine();
            System.out.println("Your new username is "+ name);
            break;
          }
          break;
        } else if (line.equals("n")) {
          break;
        } else {
          System.out.println("Invalid input. Your username is: " + name + ". "
              + "Would you like to change it? (y/n)");
        }
      }
      send(Command.SET_USERNAME, name);
    }
  }


1 个答案:

答案 0 :(得分:1)

“在调用next()或nextInt()结束之前,您可能还有其他方法正在运行,因此不会占用行的结尾。” – JB Nizet

那是问题。