java检查控制台中是否按下了一个键

Question

我想通过某种方法或事件处理程序检查用户是否在CLI应用程序中按下了某个键

诸如此类：

if(isWPressed)
    System.out.println("'W' is pressed");
if(isAPressed)
    System.out.println("'A' is pressed");

我试过这个答案： How do I check if the user is pressing a key?

但它不起作用，从导入的角度来看，我注意到它使用awt，因此在没有窗口的CLI中没有用处。我也不能用Scanner来实现这一点（正如这里所建议的：Detect a key press in console），就好像用户会按下多个按钮一样——比如w和a。我需要知道这两个按钮都被按下了

Answer 1

您需要使用keylistener，它允许获取密钥

Example 

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package javaapplication7;

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

/**
 *
 * @author wilso
 */
public class List implements KeyListener {

    @Override
    public void keyTyped(KeyEvent e) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void keyPressed(KeyEvent e) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public void keyReleased(KeyEvent e) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

}

如果你不想使用awt，那么你可以使用扫描仪或事件

@Override
public void nativeKeyPressed(NativeKeyEvent e) {
    String temp = NativeKeyEvent.getKeyText(e.getKeyCode());
    if (validHotKeys.contains(temp)) {
        if (!pressedHotKeys.contains(temp)) {
            pressedHotKeys.add(temp);
            System.out.println(pressedHotKeys.toString());
        }
    }
    if (validAlphaKeys.contains(temp)) {
        if (!pressedAlphaKeys.contains(temp)) {
            pressedAlphaKeys.add(temp);
            System.out.println(pressedAlphaKeys.toString());
        }
    }
}