使用Spring Boot实现WebSocket广播

Spring Boot提供了对WebSocket的支持，可以方便地实现广播功能。以下是实现步骤：

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-websocket</artifactId>

</dependency>

2配置WebSocket ：创建一个配置类WebSocketConfig，继承AbstractWebSocketMessageBrokerConfigurer，并配置WebSocket的端点和消息代理：

@Configuration

@EnableWebSocketMessageBroker

public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

@Override

public void configureMessageBroker(MessageBrokerRegistry config) {

config.enableSimpleBroker("/topic");

config.setApplicationDestinationPrefixes("/app");

}

@Override

public void registerStompEndpoints(StompEndpointRegistry registry) {

registry.addEndpoint("/websocket").withSockJS();

}

创建控制器 ：创建一个控制器WebSocketController，用于处理客户端发送的消息并将其广播到所有订阅了相应主题的客户端：

@Controller

public class WebSocketController {

@MessageMapping("/broadcast")

@SendTo("/topic/messages")

public String broadcastMessage(@Payload String message) {

return "广播消息: " + message;

}

客户端代码：在前端应用中，使用JavaScript和SockJS库连接到WebSocket服务器并发送/接收消息：

JavaScript

var socket = new SockJS('/websocket');

var stompClient = Stomp.over(socket);

stompClient.connect({}, function(frame) {

console.log('Connected: ' + frame);

stompClient.subscribe('/topic/messages', function(response) {

console.log('Received message: ' + response.body);

});

stompClient.send("/app/broadcast", {}, 'Hello, WebSocket!');

});