为什么我的 Java 国际象棋游戏在尝试移动棋子时出错？

Question

我为我的一项作业创建了一个简单版本的国际象棋游戏。基本上，我们只需要能够根据国际象棋规则将棋子放置到空位即可，因此无需实施检查、将死和杀死其他棋子。但是不知道为什么每次输入坐标移动棋子都不行

无论我输入什么坐标，这都是我不断得到的输出：

这是我的代码：

public class ChessGame {
  //Create 8x8 board
    private ChessPiece[][] board;
    
    public ChessGame() {
        super();
        //Initialize board
        board = new ChessPiece[8][8];
        //Place pieces on board
        placePieces();
    }
    
    //Place pieces on board
    private void placePieces() {
        //Place Pawns
        for (int i = 0; i < 8; i++) {
            board[1][i] = new Pawn(1, i);
            board[6][i] = new Pawn(6, i);
        }
        //Place Knights
        board[0][1] = new Knight(0, 1);
        board[0][6] = new Knight(0, 6);
        board[7][1] = new Knight(7, 1);
        board[7][6] = new Knight(7, 6);
        
        //Place Bishops
        board[0][2] = new Bishop(0, 2);
        board[0][5] = new Bishop(0, 5);
        board[7][2] = new Bishop(7, 2);
        board[7][5] = new Bishop(7, 5);
        
        //Place Rooks
        board[0][0] = new Rook(0, 0);
        board[0][7] = new Rook(0, 7);
        board[7][0] = new Rook(7, 0);
        board[7][7] = new Rook(7, 7);
        
        //Place King
        board[0][3] = new King(0, 3);
        board[7][3] = new King(7, 3);
        
        //Place Queen
        board[0][4] = new Queen(0, 4);
        board[7][4] = new Queen(7, 4);
    }
    
    //Check if the piece can move to given coordinates
    public boolean canMoveTo(int x, int y) {
        if (board[x][y] == null) {
            return true;
        }
        return false;
    }
    
    //Move the piece to given coordinates
    public void moveTo(int x1, int y1, int x2, int y2) {
        board[x2][y2] = board[x1][y1];
        board[x1][y1] = null;
    }
    
    //Start the game
    public void startGame() {
        //Print the initial board
        printBoard();
        
        //Loop through player turns
        while (true) {
            //Get player input
            int[] from = getInput("Player 1 - Enter coordinates to move from: ");
            int[] to = getInput("Player 1 - Enter coordinates to move to: ");
            
            //Check if the piece can move to given coordinates
            if (canMoveTo(to[0], to[1])) {
                //Move the piece
                moveTo(from[0], from[1], to[0], to[1]);
                
                //Print the updated board
                printBoard();
            } else {
                System.out.println("Illegal move, try again!");
            }
        }
    }
    
    //Get player input
    public int[] getInput(String msg) {
        //Print message
        System.out.println(msg);
        
        //Get input
            Scanner sc = new Scanner(System.in);
        int[] coords = new int[2];
        
        //Split input by space
        String[] input = sc.nextLine().split(" ");
        
        //Parse coordinates
        coords[0] = Integer.parseInt(input[0]);
        coords[1] = Integer.parseInt(input[1]);
        
        return coords;
    }
    
    //Print the board
    public void printBoard() {
        for (int i = 0; i < 8; i++) {
            for (int j = 0; j < 8; j++) {
                if (board[i][j] == null) {
                    System.out.print("- ");
                } else {
                    System.out.print(board[i][j].getName() + " ");
                }
            }
            System.out.println("");
        }
    }
    
    public static void main(String[] args) {
        ChessGame game = new ChessGame();
        game.startGame();
    }
}

abstract class ChessPiece {
    int x;
    int y;
    
    public ChessPiece(int x, int y) {
        this.x = x;
        this.y = y;
    }
    
    public int getX() {
        return x;
    }
    
    public int getY() {
        return y;
    }
    
    public abstract boolean canMoveTo(int x, int y);
    public abstract void moveTo(int x, int y);
    public abstract String getName();
}

class Pawn extends ChessPiece {
    public Pawn(int x, int y) {
        super(x, y);
    }
    
    @Override
    public boolean canMoveTo(int x, int y) {
        if (x == this.getX() + 1 && y == this.getY()) {
            return true;
        }
        return false;
    }
    
    @Override
    public void moveTo(int x, int y) {
        this.x = x;
        this.y = y;
    }
    
    @Override
    public String getName() {
        return "P";
    }
}