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SpringBoot3-整合WebSocket

CoderJia

发布于 2024-12-16 04:34:56

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文章被收录于专栏：CoderJia的工作笔记CoderJia的工作笔记

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1. 什么是WebSocket?

WebSocket 是一种网络通信协议，提供全双工通信通道，使服务器可以主动向客户端推送数据。与传统的 HTTP 请求-响应模式不同，WebSocket 在建立连接后，允许服务器和客户端之间进行双向实时通信。

主要特点：

建立在 TCP 协议之上
与 HTTP 协议有良好的兼容性
数据格式轻量，性能开销小
可以发送文本和二进制数据
没有同源限制，客户端可以与任意服务器通信

2. 环境准备

2.1 项目依赖

首先在pom.xml中添加必要的依赖：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.2.5</version>
</parent>

<dependencies>
    <!-- WebSocket依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-websocket</artifactId>
    </dependency>
    
    <!-- Web依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <!-- Lombok依赖（可选） -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

3. WebSocket配置

3.1 WebSocket配置类

创建 WebSocket 配置类，启用 WebSocket 功能并注册端点：

package com.coderjia.boot3websocket.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;

/**
 * @author CoderJia
 * @create 2024/12/15 下午 08:11
 * @Description
 **/
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(webSocketHandler(), "/websocket")
                .setAllowedOrigins("*"); // 允许跨域访问
    }

    @Bean
    public WebSocketHandler webSocketHandler() {
        // 使用自定义的WebSocket处理器
        return new CustomWebSocketHandler();
    }
}

3.2 自定义WebSocket处理器

创建自定义的 WebSocket 处理器，处理消息收发：

package com.coderjia.boot3websocket.config;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author CoderJia
 * @create 2024/12/15 下午 08:21
 * @Description
 **/
@Component
@Slf4j
public class CustomWebSocketHandler extends TextWebSocketHandler {

    // 用于存储WebSocket会话
    private final Map<String, WebSocketSession> sessions = new ConcurrentHashMap<>();

    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        String sessionId = session.getId();
        sessions.put(sessionId, session);
        log.info("WebSocket连接建立成功：{}", sessionId);
    }

    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        String payload = message.getPayload();
        log.info("收到消息：{}", payload);

        // 发送回复消息
        String replyMessage = "服务器收到消息：" + payload;
        session.sendMessage(new TextMessage(replyMessage));
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        String sessionId = session.getId();
        sessions.remove(sessionId);
        log.info("WebSocket连接关闭：{}", sessionId);
    }

    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        log.error("WebSocket传输错误", exception);
    }

    // 广播消息给所有连接的客户端
    public void broadcastMessage(String message) {
        sessions.values().forEach(session -> {
            try {
                session.sendMessage(new TextMessage(message));
            } catch (IOException e) {
                log.error("广播消息失败", e);
            }
        });
    }
}

4. 控制器

创建 REST 控制器，用于测试消息广播：

@RestController
@RequestMapping("/api/websocket")
public class WebSocketController {
    
    private final CustomWebSocketHandler webSocketHandler;
    
    public WebSocketController(CustomWebSocketHandler webSocketHandler) {
        this.webSocketHandler = webSocketHandler;
    }
    
    @PostMapping("/broadcast")
    public ResponseEntity<String> broadcastMessage(@RequestBody String message) {
        webSocketHandler.broadcastMessage(message);
        return ResponseEntity.ok("消息广播成功");
    }
}

5. 前端实现

5.1 HTML页面

<!DOCTYPE html>
<html lang="en">
<head>
    <title>WebSocket测试</title>
</head>
<body>
    <div>
        <h2>WebSocket测试页面</h2>
        <div>
            <input type="text" id="messageInput" placeholder="输入消息">
            <button onclick="sendMessage()">发送</button>
        </div>
        <div id="messages" style="margin-top: 20px;"></div>
    </div>
    
    <script>
        let ws = null;
        
        function connect() {
            ws = new WebSocket('ws://localhost:8080/websocket');
            
            ws.onopen = function() {
                console.log('WebSocket连接已建立');
                appendMessage('系统消息：连接已建立');
            };
            
            ws.onmessage = function(event) {
                appendMessage('收到消息：' + event.data);
            };
            
            ws.onclose = function() {
                console.log('WebSocket连接已关闭');
                appendMessage('系统消息：连接已关闭');
            };
            
            ws.onerror = function(error) {
                console.error('WebSocket错误：', error);
                appendMessage('系统消息：连接发生错误');
            };
        }
        
        function sendMessage() {
            const messageInput = document.getElementById('messageInput');
            const message = messageInput.value;
            
            if (ws && message) {
                ws.send(message);
                appendMessage('发送消息：' + message);
                messageInput.value = '';
            }
        }
        
        function appendMessage(message) {
            const messagesDiv = document.getElementById('messages');
            const messageElement = document.createElement('div');
            messageElement.textContent = message;
            messagesDiv.appendChild(messageElement);
        }
        
        // 页面加载完成后连接WebSocket
        window.onload = connect;
    </script>
</body>
</html>

6. 测试WebSocket功能

启动 SpringBoot 应用
打开多个浏览器窗口访问 HTML 页面
在任意窗口发送消息，观察其他窗口是否收到消息
使用 POST 请求测试广播功能：

curl -X POST http://localhost:8080/api/websocket/broadcast \
     -H "Content-Type: text/plain" \
     -d "这是一条广播消息"

7. 进阶功能

7.1 心跳检测

为了保持WebSocket连接的稳定性，可以实现心跳机制：

    @Scheduled(fixedRate = 10000) // 每10秒发送一次心跳，需要启动类或配置类上添加@EnableScheduling
    public void sendHeartbeat() {
        String heartbeat = "heartbeat";
        sessions.values().forEach(session -> {
            try {
                session.sendMessage(new TextMessage(heartbeat));
            } catch (IOException e) {
                log.error("发送心跳消息失败", e);
            }
        });
    }

7.2 消息重试机制

当消息发送失败时，实现重试机制：

public void sendMessageWithRetry(WebSocketSession session, String message, int maxRetries) {
    int retryCount = 0;
    while (retryCount < maxRetries) {
        try {
            session.sendMessage(new TextMessage(message));
            return;
        } catch (IOException e) {
            retryCount++;
            log.error("消息发送失败，尝试重试 {}/{}", retryCount, maxRetries);
            try {
                Thread.sleep(1000);
            } catch (InterruptedException ie) {
                Thread.currentThread().interrupt();
                break;
            }
        }
    }
    log.error("消息发送失败，达到最大重试次数");
}