Spring Boot 与 Vue 实现 WebSocket 实时匹配系统

前端与后端建立连接

views/pk/PKIndex.vue:

<template>
  <PlayGround/>
</template>
<script>
import PlayGround from '@/components/PlayGround.vue';
import { onMounted, onUnmounted } from 'vue';
import { useStore } from 'vuex';

export default {
  name: "PKIndex",
  components: { PlayGround },
  setup() {
    const store = useStore();
    const socketUrl = `ws://127.0.0.1:3000/websocket/${store.state.user.id}/`;
    let socket = null;

    onMounted(() => {
      socket = new WebSocket(socketUrl);
      socket.onopen = () => {
        console.log("connected!");
        store.commit("updateSocket", socket);
      };
      socket.onmessage = msg => {
        const data = JSON.parse(msg.data);
        console.log(data);
      };
      socket.onclose = () => {
        console.log("disconnected!");
      };
    });

    onUnmounted(() => {
      if (socket) socket.close();
    });
  }
};
</script>
<style scoped></style>

将 token 改成 JWT 验证

若使用 userId 建立 WebSocket 连接，用户可伪装成任意用户，因此这是不安全的。应使用 JWT Token 进行身份验证。

修改连接 URL：

const socketUrl = `ws://127.0.0.1:3000/websocket/${store.state.user.token}/`;

添加 WebSocket 的 JWT 验证，根据 token 判断用户是否存在。

consumer/utils/JwtAuthentication.java:

package org.example.backend.consumer.utils;

import io.jsonwebtoken.Claims;
import org.example.backend.utils.JwtUtil;

public class JwtAuthentication {
  public static Integer getUserId(String token) {
    int userId = -1; // -1 表示不存在
    try {
      Claims claims = JwtUtil.parseJWT(token);
      userId = Integer.parseInt(claims.getSubject());
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
    return userId;
  }
}

修改后端 WebSocketServer.java：

@OnOpen
public void onOpen(Session session, @PathParam("token") String token) throws IOException {
  this.session = session;
  System.out.println("connected to websocket");
  Integer userId = JwtAuthentication.getUserId(token);
  User user = userMapper.selectById(userId);
  if (user != null) {
    users.put(userId, this);
    this.user = user;
  } else {
    this.session.close();
  }
}

如果可以正常解析出 JWT token 则表示登录成功，否则直接关闭连接。

实现前端逻辑

对战界面和匹配界面的切换

views/pk/PKIndex.vue:

<template>
  <PlayGround v-if="$store.state.pk.status === 'playing'"/>
  <MatchGround v-if="$store.state.pk.status === 'matching'"/>
</template>

创建匹配页面 components/MatchGround.vue：

<template>
  <div class="matchground"></div>
</template>
<script>
export default {};
</script>
<style scoped>
  div.matchground {
    width: 60vw;
    height: 70vh;
    margin: 40px auto;
    background-color: lightblue;
  }
</style>

设置此时的状态是匹配。

最终效果：

匹配界面

使用 Grid 系统布局，自己头像与对手头像比例为 6:6。

逻辑很简单，点击匹配按钮，就向后端发送请求开始匹配。

components/MatchGround.vue:

<template>
  <div class="matchground">
    <div class="row">
      <div class="col-6">
        <div class="user-photo">
          <img :src="$store.state.user.photo" alt="">
        </div>
        <div class="user-username">{{ $store.state.user.username }}</div>
      </div>
      <div class="col-6">
        <div class="user-photo">
          <img :src="$store.state.pk.opponent_photo" alt="">
        </div>
        <div class="user-username">{{ $store.state.pk.opponent_username }}</div>
      </div>
      <div class="col-12" style="text-align: center; padding-top: 15vh;">
        <button @click="click_match_btn" type="button" class="btn btn-warning btn-lg">{{ match_btn_info }}</button>
      </div>
    </div>
  </div>
</template>
<script>
import { ref } from 'vue';
import { useStore } from 'vuex';

export default {
  setup() {
    const store = useStore();
    let match_btn_info = ref("开始匹配");

    const click_match_btn = () => {
      if (match_btn_info.value === "开始匹配") {
        match_btn_info.value = "取消";
        store.state.pk.socket.send(JSON.stringify({ event: "start-matching" }));
      } else {
        match_btn_info.value = "开始匹配";
        store.state.pk.socket.send(JSON.stringify({ event: "stop-matching" }));
      }
    };

    return { match_btn_info, click_match_btn };
  }
};
</script>
<style scoped>
  div.matchground { width: 60vw; height: 70vh; margin: 40px auto; background-color: rgba(50,50,50,0.5); }
  div.user-photo { text-align: center; padding-top: 10vh; }
  div.user-photo > img { border-radius: 50%; width: 20vh; }
  div.user-username { text-align: center; font-size: 24px; font-weight: 600; color: white; padding-top: 2vh; }
</style>

整体结构：

• 外层 div.matchground 作为容器。
• 内部是 Bootstrap 栅格布局 row + col-6/col-12。
• 左侧显示当前用户信息（头像、用户名）。
• 右侧显示对手信息（来自 Vuex 状态）。
• 中间有匹配按钮，点击会改变按钮文字并通过 WebSocket 发送匹配事件给后端。

后端 consumer/WebSocketServer.java：

@Component
@ServerEndpoint("/websocket/{token}")
public class WebSocketServer {
  private final static ConcurrentHashMap<Integer, WebSocketServer> users = new ConcurrentHashMap<>();
  private final static CopyOnWriteArraySet<User> matchpool = new CopyOnWriteArraySet<>();
  private User user;
  private Session session = null;
  private static UserMapper userMapper;

  @Autowired
  public void setUserMapper(UserMapper userMapper) {
    WebSocketServer.userMapper = userMapper;
  }

  @OnOpen
  public void onOpen(Session session, @PathParam("token") String token) throws IOException {
    this.session = session;
    System.out.println("connected!");
    Integer userId = JwtAuthentication.getUserId(token);
    this.user = userMapper.selectById(userId);
    if (this.user != null) {
      users.put(userId, this);
    } else {
      this.session.close();
    }
    System.out.println(users);
  }

  @OnClose
  public void onClose() {
    System.out.println("disconnected!");
    if (this.user != null) {
      users.remove(this.user.getId());
      matchpool.remove(this.user);
    }
  }

  private void startMatching() {
    System.out.println("start matching!");
    matchpool.add(this.user);
    while (matchpool.size() >= 2) {
      Iterator<User> it = matchpool.iterator();
      User a = it.next(), b = it.next();
      matchpool.remove(a);
      matchpool.remove(b);
      Game game = new Game(13, 14, 20);
      game.createMap();
      JSONObject respA = new JSONObject();
      respA.put("event", "start-matching");
      respA.put("opponent_username", b.getUsername());
      respA.put("opponent_photo", b.getPhoto());
      respA.put("gamemap", game.getG());
      users.get(a.getId()).sendMessage(respA.toJSONString());

      JSONObject respB = new JSONObject();
      respB.put("event", "start-matching");
      respB.put("opponent_username", a.getUsername());
      respB.put("opponent_photo", a.getPhoto());
      respB.put("gamemap", game.getG());
      users.get(b.getId()).sendMessage(respB.toJSONString());
    }
  }

  private void stopMatching() {
    System.out.println("stop matching");
    matchpool.remove(this.user);
  }

  @OnMessage
  public void onMessage(String message, Session session) {
    System.out.println("receive message!");
    JSONObject data = JSONObject.parseObject(message);
    String event = data.getString("event");
    if ("start-matching".equals(event)) {
      startMatching();
    } else if ("stop-matching".equals(event)) {
      stopMatching();
    }
  }

  @OnError
  public void onError(Session session, Throwable error) {
    error.printStackTrace();
  }

  public void sendMessage(String message) {
    synchronized (this.session) {
      try {
        this.session.getBasicRemote().sendText(message);
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}

后端返回信息给前端后，在前端接受并处理信息。

views/PKIndex.vue:

<template>
  <PlayGround v-if="$store.state.pk.status === 'playing'"/>
  <MatchGround v-if="$store.state.pk.status === 'matching'"/>
</template>
<script>
import PlayGround from '@/components/PlayGround.vue';
import MatchGround from '@/components/MatchGround.vue';
import { onMounted, onUnmounted } from 'vue';
import { useStore } from 'vuex';

export default {
  components: { PlayGround, MatchGround },
  setup() {
    const store = useStore();
    const socketUrl = `ws://127.0.0.1:3000/websocket/${store.state.user.token}/`;
    let socket = null;

    onMounted(() => {
      store.commit("updateOpponent", {
        username: "我的对手",
        photo: "https://cdn.acwing.com/media/article/image/2022/08/09/1_1db2488f17-anonymous.png"
      });
      socket = new WebSocket(socketUrl);
      socket.onopen = () => {
        console.log("connected!");
        store.commit("updateSocket", socket);
      };
      socket.onmessage = msg => {
        const data = JSON.parse(msg.data);
        if (data.event === "start-matching") {
          store.commit("updateOpponent", {
            username: data.opponent_username,
            photo: data.opponent_photo
          });
          setTimeout(() => {
            store.commit("updateStatus", "playing");
          }, 2000);
          store.commit("updateGamemap", data.gamemap);
        }
      };
      socket.onclose = () => {
        console.log("disconnected!");
      };
    });

    onUnmounted(() => {
      if (socket) socket.close();
      store.commit("updateStatus", "matching");
    });
  }
};
</script>

基于 WebSocket 的游戏匹配系统流程：

• 组件挂载时，通过 WebSocket 与服务器建立连接。
• 匹配阶段，用户与服务器实时交换数据，匹配成功后显示对手信息并开始游戏。
• 游戏过程中的状态（如对手信息和游戏地图）通过 Vuex 管理，并根据状态动态渲染不同的界面组件（MatchGround 或 PlayGround）。
• 组件卸载时关闭 WebSocket 连接，确保没有资源泄漏。

解决同步问题

首先要在后端创建一个 Game 类实现游戏流程，其实就是把之前在前端写的 JS 全部翻译成 Java。

consumer/utils/Game.java:

package org.example.backend.consumer.utils;

import java.util.Random;

public class Game {
  private final Integer rows;
  private final Integer cols;
  private final Integer inner_walls_count;
  private final int[][] g;
  private static final int[] dx = {-1, 0, 1, 0}, dy = {0, 1, 0, -1};

  public Game(Integer rows, Integer cols, Integer inner_walls_count) {
    this.rows = rows;
    this.cols = cols;
    this.inner_walls_count = inner_walls_count;
    this.g = new int[rows][cols];
  }

  public int[][] getG() {
    return g;
  }

  private boolean check_connectivity(int sx, int sy, int tx, int ty) {
    if (sx == tx && sy == ty) return true;
    g[sx][sy] = 1;
    for (int i = 0; i < 4; i++) {
      int x = sx + dx[i], y = sy + dy[i];
      if (x >= 0 && x < this.rows && y >= 0 && y < this.cols && g[x][y] == 0) {
        if (check_connectivity(x, y, tx, ty)) {
          g[sx][sy] = 0;
          return true;
        }
      }
    }
    g[sx][sy] = 0;
    return false;
  }

  private boolean draw() {
    for (int i = 0; i < this.rows; i++) {
      for (int j = 0; j < this.cols; j++) {
        g[i][j] = 0;
      }
    }
    for (int r = 0; r < this.rows; r++) {
      g[r][0] = g[r][this.cols - 1] = 1;
    }
    for (int c = 0; c < this.cols; c++) {
      g[0][c] = g[this.rows - 1][c] = 1;
    }
    Random random = new Random();
    for (int i = 0; i < this.inner_walls_count / 2; i++) {
      for (int j = 0; j < 1000; j++) {
        int r = random.nextInt(this.rows);
        int c = random.nextInt(this.cols);
        if (g[r][c] == 1 || g[this.rows - 1 - r][this.cols - 1 - c] == 1) continue;
        if (r == this.rows - 2 && c == 1 || r == 1 && c == this.cols - 2) continue;
        g[r][c] = g[this.rows - 1 - r][this.cols - 1 - c] = 1;
        break;
      }
    }
    return check_connectivity(this.rows - 2, 1, 1, this.cols - 2);
  }

  public void createMap() {
    for (int i = 0; i < 1000; i++) {
      if (draw()) break;
    }
  }
}

Game 类主要用于生成一个带有边界和内部随机墙壁的连通游戏地图，使用了深度优先搜索（DFS）算法来检查地图的连通性。

在前端的 pk.js 中增加 gamemap 状态：

export default {
  state: {
    status: "matching",
    socket: null,
    opponent_username: "",
    opponent_photo: "",
    gamemap: null,
  },
  mutations: {
    updateSocket(state, socket) { state.socket = socket; },
    updateOpponent(state, opponent) { 
      state.opponent_username = opponent.username; 
      state.opponent_photo = opponent.photo; 
    },
    updateStatus(state, status) { state.status = status; },
    updateGamemap(state, gamemap) { state.gamemap = gamemap; }
  },
  actions: {},
  modules: {}
};

展示结果：

总结

本文介绍了如何使用 WebSocket 实现前端与后端的实时匹配。前端负责展示用户的操作界面并通过 WebSocket 与后端保持实时连接，后端则处理客户端的请求并返回实时数据。前后端需紧密配合以确保实时数据的正确传输和处理。