代码重构-以贪吃蛇为示例(一)-重构之前
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2022-05-21 13:58:30
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题外话:
今天中午做到电脑前没事干,就写个贪吃蛇游戏,写着写着就发现变量太多了,函数调用太乱了,逻辑越来越混乱,于是就想重构一下。但是有想一想,干脆把重构的过程记录下来,大家也分享分享,还能提高一下知名度,何乐而不为呢?
所以……所以……我硬着头皮在不重构的情况下写完了一个简单的贪吃蛇(WTF!)
/*--------------------------------------------无耻的分隔栏----------------------------------------------------- */
介绍下功能:
Swing组件完成的贪吃蛇游戏,通过键盘的方向键改变方向,吃到虫子增长长度,每吃掉一个虫子,移动速度会增长,撞到四周或者自己提示游戏结束。记录分数(但是没显示,因为不重构写不下去了),没有重新游戏(留到重构以后再写)。
界面:
(恐怖的)代码:
package snakes; import java.awt.Color; import java.awt.Graphics; import java.awt.Point; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; import java.util.Map; import java.util.Random; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; public class Game extends JPanel implements KeyListener { /** * 贪吃蛇行走的方向 */ enum Direction { UP { @Override public Point getNextPoint(Point p) { return new Point(p.x, p.y - 1); } @Override public Point getPreviousPoint(Point p) { return new Point(p.x, p.y + 1); } @Override public boolean isAvailable(Direction d) { if (d == Direction.UP || d == Direction.DOWM) { return false; } return true; } }, DOWM { @Override public Point getNextPoint(Point p) { return new Point(p.x, p.y + 1); } @Override public Point getPreviousPoint(Point p) { return new Point(p.x, p.y - 1); } @Override public boolean isAvailable(Direction d) { if (d == Direction.UP || d == Direction.DOWM) { return false; } return true; } }, LEFT { @Override public Point getNextPoint(Point p) { return new Point(p.x - 1, p.y); } @Override public Point getPreviousPoint(Point p) { return new Point(p.x + 1, p.y); } @Override public boolean isAvailable(Direction d) { if (d == LEFT || d == RIGHT) { return false; } return true; } }, RIGHT { @Override public Point getNextPoint(Point p) { return new Point(p.x + 1, p.y); } @Override public Point getPreviousPoint(Point p) { return new Point(p.x - 1, p.y); } @Override public boolean isAvailable(Direction d) { if (d == LEFT || d == RIGHT) { return false; } return true; } }; /** * 沿此方向的下一个点 * @param p * @return */ public abstract Point getNextPoint(Point p); /** * 沿此方向的上一个点 * @param p * @return */ public abstract Point getPreviousPoint(Point p); /** * 可以转动的方向 * @param d * @return */ public abstract boolean isAvailable(Direction d); } private static final long serialVersionUID = -7269846451378790762L; private static final Random random = new Random(); public static void main(String[] args) { JFrame j = new JFrame("贪吃蛇"); Game contentPane = new Game(); j.setContentPane(contentPane); j.addKeyListener(contentPane); j.setBounds(20, 20, 700, 500); j.setVisible(true); j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } /** * 分数 */ private int score = 0; /** * 每一个单元格的尺寸,像素 */ private final int sellSize = 20; /** * 地图横向包含的单元格数 */ private final int tableWidth = 30; /** * 地图纵向包含的单元格数 */ private final int tableHeight = 20; /** * 贪吃蛇的点链表 */ private final LinkedList<Point> snake = new LinkedList<Point>(); private final Direction[] da = { Direction.UP, Direction.DOWM, Direction.LEFT, Direction.RIGHT }; private Direction direction = da[random.nextInt(4)]; /** * 虫子的位置 */ private Point target = new Point(random.nextInt(tableWidth), random.nextInt(tableHeight)); /** *贪吃蛇初始长度 */ private final int initsnakeLenght = 3; private final Map<Integer, Direction> keyMap = new HashMap<Integer, Direction>(); /** * 移动速度 */ private volatile long speed = 1; private volatile long crrTime = System.currentTimeMillis(); public Game() { keyMap.put(KeyEvent.VK_UP, Direction.UP); keyMap.put(KeyEvent.VK_DOWN, Direction.DOWM); keyMap.put(KeyEvent.VK_LEFT, Direction.LEFT); keyMap.put(KeyEvent.VK_RIGHT, Direction.RIGHT); Point p = new Point(random.nextInt(tableWidth - initsnakeLenght >> 1) + initsnakeLenght, random.nextInt(tableHeight - initsnakeLenght >> 1) + initsnakeLenght); snake.add(p); for (int i = 0; i < initsnakeLenght - 1; ++i) { p = direction.getPreviousPoint(p); snake.add(p); } /** * 游戏主循环线程 */ new Thread() { @Override public void run() { while (true) { if (System.currentTimeMillis() - crrTime > 500 / speed) { synchronized (Game.class) { moveSnake(); if (!checkSnack()) { JOptionPane.showMessageDialog(null, "Game Over!"); return; } } repaint(); crrTime = System.currentTimeMillis(); } } }; }.start(); } /** * 判断贪吃蛇是否撞墙或撞到自己 * @return */ protected boolean checkSnack() { Point p = snake.getFirst(); int x = p.x, y = p.y; if (x < 0 || x >= tableWidth || y < 0 || y >= tableHeight) { return false; } Iterator<Point> it = snake.iterator(); it.next(); while (it.hasNext()) { Point pBody = it.next(); if (p.equals(pBody)) { return false; } } return true; } @Override public void keyPressed(KeyEvent e) { } @Override public void keyReleased(KeyEvent e) { Direction newd = keyMap.get(e.getKeyCode()); if (newd != null && direction.isAvailable(newd)) { direction = newd; synchronized (Game.class) { moveSnake(); if (!checkSnack()) { JOptionPane.showMessageDialog(null, "Game Over!"); return; } } repaint(); crrTime = System.currentTimeMillis(); } } @Override public void keyTyped(KeyEvent e) { } /** * 移动贪吃蛇,包括吃虫 */ private void moveSnake() { snake.addFirst(direction.getNextPoint(snake.getFirst())); if (snake.getFirst().equals(target)) { target = new Point(random.nextInt(tableWidth), random.nextInt(tableHeight)); ++speed; ++score; } else { snake.removeLast(); } } /** * 绘制图形 */ @Override protected void paintComponent(Graphics g) { g.setColor(new Color(0x555555)); g.clearRect(0, 0, tableWidth * sellSize, tableHeight * sellSize); for (int i = 0; i < tableWidth; i++) { for (int j = 0; j < tableHeight; ++j) { g.drawRect(i * sellSize, j * sellSize, sellSize, sellSize); } } g.setColor(new Color(0x3399cc)); for (Point p : snake) { g.fillRect(p.x * sellSize, p.y * sellSize, sellSize, sellSize); } g.setColor(new Color(0x115599)); Point p = snake.peek(); g.fillRect(p.x * sellSize, p.y * sellSize, sellSize, sellSize); g.setColor(new Color(0xdd7744)); g.fillRect(target.x * sellSize, target.y * sellSize, sellSize, sellSize); } }
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