具有用户输入击键的Java Switch

Question

I'm making a snake game in Java and need to use user keystrokes to control the direction of the movement. Is this possible through a switch statement? I was originally using a Scanner s = new Scanner(System.in) to allow user to type 'u','d', etc. to move snake, but I would like to use the keyboard arrows instead.

Here is what I have right now:

public void controlSnake(){

Scanner s = new Scanner(System.in);
String inputString = s.next();

    switch (inputString) {
    case "u":
    case "U":
        snake.changeDirection(Point.NORTH);
        break;
    case "d":
    case "D":
        snake.changeDirection(Point.SOUTH);
        break;
    case "r":
    case "R":
        snake.changeDirection(Point.EAST);
        break;
    case "l":
    case "L":
        snake.changeDirection(Point.WEST);
        break;
    } 

}

I was going to insert something like this, but not sure how to:

     map1.put(KeyStroke.getKeyStroke("LEFT"), "moveLeft");

     getActionMap().put("moveLeft", new AbstractAction() {
     private static final long serialVersionUID = 1L;

     public void actionPerformed(ActionEvent e) {
     snake.changeDirection(Point.WEST);

     }
     });

What would be the best way to accomplish this?

Answer 1

It is possible to use switch statement with String from JDK 7:

Strings in switch Statements

And seems you are developing a console game. If you are using Swing, you can consider using InputMap together with ActionMap instead:

How to Use Key Bindings

Answer 2

I see you are using Swing. You can make use of KeyListener interface. Something like this.

yourButton.addKeyListener(new KeyListener(){
         @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode() == KeyEvent.VK_UP){
                    snake.changeDirection(Point.NORTH);
                }
                if(e.getKeyCode() == KeyEvent.VK_DOWN){
                    snake.changeDirection(Point.SOUTH);
                }
                //Likewise for left and right arrows
            }

            @Override
            public void keyTyped(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.
            }
    });