使用SpringBoot搭建实时通信服务

安宇雨 - 随手采集
2023-04-10 09:58:04
随手采集
0000-未整理-等待研究

在软件开发过程中，经常需要获取服务器端数据来展示给用户，对于数据的及时性有要求的场景，我们可能会采用长轮询等方式，来以一定的频率向服务器发起请求拉取数据，轮询方式会持续占用系统资源，效率较低，那么有没有一种解决方案，能做到服务器端有数据更新，及时通知客户端呢？通过使用websocket技术，我们可以做到客户端与服务器端的全双工通信，两端都可以实时的发送数据给对方~，下面就给大家介绍下SpringBoot中怎么整合websocket技术

SpringBoot版本 2.4.5

使用方式

1.修改SpringBoot工程中的pom.xml配置，增加websocket的依赖

**<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>**

2.修改SpringBoot工程启动类，添加@EnableWebSocket注解来启用websocket能力支持

3.添加websocket配置
完整代码参考：https://github.com/netbuffer/spring-boot-websocket-demo/blob/master/src/main/java/cn/netbuffer/springboot/websocket/demo/config/SpringWebSocketConfig.java

**@Configuration
public class SpringWebSocketConfig implements WebSocketConfigurer {

@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
//添加通信地址路径
registry.addHandler(buildTextHandler(), "/ws").setAllowedOrigins("*");
}

@Bean
public WebSocketHandler buildTextHandler() {
//添加消息处理器
return new TextHandler();
}

}**

4.实现自己的消息处理器
完整代码参考：https://github.com/netbuffer/spring-boot-websocket-demo/blob/master/src/main/java/cn/netbuffer/springboot/websocket/demo/websocket/handler/TextHandler.java

**@Slf4j
public class TextHandler extends TextWebSocketHandler {

@Override
protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
if (session.isOpen()) {
log.info("receive websocket message：{} session:{}", message, session.getId());
TextMessage returnMessage = new TextMessage(message.getPayload() + " received at server");
session.sendMessage(returnMessage);
}
}

@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
super.afterConnectionEstablished(session);
//建立连接后保存WebSocketSession会话
SessionManager.put(session.getId(), session);
log.info("session[{}] afterConnectionEstablished", session.getId());
}

@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
log.info("session[{}] afterConnectionClosed", session.getId());
//释放连接后移除WebSocketSession会话
SessionManager.remove(session.getId());
}
}**

5.建立Controller控制器层映射方法，来测试主动推送消息到客户端
完整代码参考：https://github.com/netbuffer/spring-boot-websocket-demo/blob/master/src/main/java/cn/netbuffer/springboot/websocket/demo/controller/WebsocketController.java

**@RestController
@RequestMapping("/ws")
public class WebsocketController {

@GetMapping("{session}/send")
public void send(@PathVariable("session") String session, String msg) {
WebSocketMessage webSocketMessage = new TextMessage(msg);
try {
SessionManager.get(session).sendMessage(webSocketMessage);
} catch (IOException e) {
e.printStackTrace();
}
}

}**

6.编写客户端html代码验证websocket能力
完整代码参考：https://github.com/netbuffer/UItest/blob/master/websocket/index.html)

**<script type="text/javascript">
var ws = new WebSocket("ws://localhost:17000/ws");
ws.onopen = function () {
console.log("Connection open ...");
};
ws.onmessage = function (r) {
console.log("Received Message: " + r.data);
};
ws.onclose = function () {
console.log("Connection closed.");
};
</script>
<input name="text" placeholder="请输入文本内容" /><button onclick="ws.send(document.querySelector('input[name=\'text\']').value)">send</button> <button onclick="ws.close()">close</button>**