用Java写一个贪吃蛇游戏

很高兴为您提供一个用Java写的贪吃蛇游戏代码。这个游戏是一个控制台应用程序，您可以在控制台上玩这个游戏。下面是完整的代码：

import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class SnakeGame {
    private final int width;
    private final int height;
    private int score;
    private final ArrayList<Point> snake;
    private Point food;
    private final Random rand = new Random();
    private Direction direction = Direction.RIGHT;
    private boolean gameOver = false;

    public SnakeGame(int width, int height) {
        this.width = width;
        this.height = height;
        this.score = 0;
        this.snake = new ArrayList<>();
        this.snake.add(new Point(width / 2, height / 2));
        this.food = generateFood();
    }

    public void play() {
        Scanner scanner = new Scanner(System.in);
        while (!gameOver) {
            System.out.println("Score: " + score);
            draw();
            System.out.print("Enter direction (up/down/left/right): ");
            String input = scanner.nextLine();
            switch (input) {
                case "up":
                    direction = Direction.UP;
                    break;
                case "down":
                    direction = Direction.DOWN;
                    break;
                case "left":
                    direction = Direction.LEFT;
                    break;
                case "right":
                    direction = Direction.RIGHT;
                    break;
                default:
                    System.out.println("Invalid direction.");
                    break;
            }
            move();
            checkCollision();
            if (!gameOver && snake.get(0).equals(food)) {
                score++;
                snake.add(food);
                food = generateFood();
            }
        }
        System.out.println("Game over! Final score: " + score);
    }

    private void draw() {
        char[][] grid = new char[height][width];
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                grid[i][j] = '.';
            }
        }
        for (Point p : snake) {
            grid[p.getY()][p.getX()] = 'o';
        }
        grid[food.getY()][food.getX()] = 'x';
        for (int i = 0; i < width + 2; i++) {
            System.out.print("-");
        }
        System.out.println();
        for (int i = 0; i < height; i++) {
            System.out.print("|");
            for (int j = 0; j < width; j++) {
                System.out.print(grid[i][j]);
            }
            System.out.println("|");
        }
        for (int i = 0; i < width + 2; i++) {
            System.out.print("-");
        }
        System.out.println();
    }

    private void move() {
        Point head = snake.get(0);
        Point newHead;
        switch (direction) {
            case UP:
                newHead = new Point(head.getX(), head.getY() - 1);
                break;
            case DOWN:
                newHead = new Point(head.getX(), head.getY() + 1);
                break;
            case LEFT:
                newHead = new Point(head.getX() - 1, head.getY());
                break;
            case RIGHT:
                newHead = new Point(head.getX() + 1, head.getY());
                break;
            default:
                throw new IllegalStateException("Invalid direction.");
        }
        snake.add(0, newHead);
        snake.remove(snake.size() - 1);
    }

    private void checkCollision() {
        Point head = snake.get(0);
        if (head.getX() < 0 || head.getX() >= width || head.getY() < 0 || head.getY() >= height) {
            gameOver = true;
            return;
        }
        for (int i = 1; i < snake.size(); i++) {
            if (head.equals(snake.get(i))) {
                gameOver = true;
                return;
            }
        }
    }

    private Point generateFood() {
        Point food;
        do {
            int x = rand.nextInt(width);
            int y = rand.nextInt(height);
            food = new Point(x, y);
        } while (snake.contains(food));
        return food;
    }

    public static void main(String[] args) {
        SnakeGame game = new SnakeGame(20, 10);
        game.play();
    }

    private enum Direction {
        UP, DOWN, LEFT, RIGHT
    }

    private static class Point {
        private final int x;
        private final int y;

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }

        public int getX() {
            return x;
        }

        public int getY() {
            return y;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Point point = (Point) o;
            return x == point.x && y == point.y;
        }

        @Override
        public int hashCode() {
            return Objects.hash(x, y);
        }
    }
}

这个游戏的核心是一个 `SnakeGame` 类，它包含了贪吃蛇游戏的逻辑。在 `main` 方法中，我们创建了一个 `SnakeGame` 对象并调用 `play` 方法来启动游戏。在 `play` 方法中，我们从控制台读取用户输入的方向，并根据方向移动贪吃蛇。在每一次移动后，我们检查是否发生了碰撞，如果发生了碰撞，游戏结束。如果贪吃蛇吃到了食物，我们增加分数并且在贪吃蛇的身体上增加一个新的格子。

这个游戏也使用了一个 `Point` 类来表示贪吃蛇的身体和食物的位置。我们使用一个二维字符数组来表示游戏的画面，并使用 `draw` 方法来在控制台上输出这个画面。在 `checkCollision` 方法中，我们检查是否有任何碰撞发生，包括贪吃蛇是否碰到了游戏边界或者碰到了它自己。

这个贪吃蛇游戏是一个简单而有趣的练手项目，它可以帮助您加深对Java编程语言的理解。