java - 用户输入try&catch

Question

我正在尝试异常(exception)，因此当用户输入数字而不是字符时，会弹出一条错误消息，尝试编写 try/catch，

package Controller;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.InputMismatchException;
import java.util.Scanner;

import javax.swing.JButton;

import Model.BoardSpace;
import Model.PlayerMarker;
import Model.PlayerObject;
import View.MainFrame;
import View.WelcomeScreen;
import View.WinScreen;

public class GameInit implements Game {

    private WelcomeScreen welcomeScreen = new WelcomeScreen();

      public GameInit() {

      }

      public void gameInit() {
      initPlayers();

      welcomeScreen.inputBoardSize();
      setButtons(welcomeScreen.getButtons());
      boardSizeListeners();

      }


private PlayerObject playerOne, playerTwo, victorPlayer;
private String input;
private int players = 1;
private boolean gameRunning = true;
WinScreen win = new WinScreen();

private static GameMechanics mechanics = GameMechanics.getInstance();
private MainFrame mainFrame = new MainFrame();
private int row, col;
private JButton buttons[];
// used on size selection
private int boardSizeOption;

我希望它打印“请输入一个字符”而不是“数字”。我怎样才能正确填写？

public String userInputToVariable() {

try {
    input = welcomeScreen.playerNameWindows();
    return input;
    }
catch (Exception e) {

    }
}

谢谢。

Answer 1

您可以使用 Java 已经从 java.lang.Character 类中专门用于此目的的方法。如果字符是数字，则返回 true。

Character.isDigit(string.charAt(index))

如果你有兴趣，它的实现如下:

public static boolean isDigit(char ch) {
    return isDigit((int)ch);
}

public static boolean isDigit(int codePoint) {
    return getType(codePoint) == Character.DECIMAL_DIGIT_NUMBER;
}