我正在使用Spring 5：如何从Stomp客户端检测SUBSCRIBE消息？
根据我的理解，@SubscribeMapping应该在客户端订阅主题时调用我的控制器方法，但这不会发生。
这是我的服务器控制器：
@Controller
public class MessageController {
// ...
@MessageMapping("/chat/{mId}")
@SendTo("/topic/messages")
public OutputMessage send(Message message, @DestinationVariable("mId") String mid, MessageHeaders headers, MessageHeaderAccessor accessor) throws Exception {
// ...
}
@SuppressWarnings("unused")
@SubscribeMapping({ "/", "/chat", "/topic/messages", "/messages", "/*" })
public void listen(Message message, MessageHeaders headers, MessageHeaderAccessor accessor) throws Exception {
int i = 0;
System.out.println("subscribed");
}
}
服务器配置：
@Configuration
@ComponentScan(basePackages= { "websockets" })
@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("/chat");
registry.addEndpoint("/chat").withSockJS();
}
@Override
public void configureWebSocketTransport(WebSocketTransportRegistration registry) {
WebSocketMessageBrokerConfigurer.super.configureWebSocketTransport(registry);
}
}
和javascript客户端：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Chat WebSocket</title>
<script src="sockjs.js"></script>
<script src="stomp.js"></script>
<script type="text/javascript">
// ...
function connect() {
var sock = new SockJS('/<webapp-context>/chat');
stompClient = Stomp.over(sock);
stompClient.connect({}, function(frame) {
setConnected(true);
console.log('Connected: ' + frame);
stompClient.subscribe('/topic/messages', function(messageOutput) {
showMessageOutput(JSON.parse(messageOutput.body));
});
stompClient.subscribe('/topic/messages/13', function(messageOutput) {
showMessageOutput(JSON.parse(messageOutput.body));
});
});
}
// ...
</script>
</head>
<body onload="/*disconnect()*/">
<!-- ... -->
</body>
</html>
该代码改编自Intro to WebSockets with Spring。
如this answer和in the docs所示，我可以使用一个拦截器，但@SubscribeMapping如何工作呢？
您还需要将“主题”注册为应用程序目标主题config.setApplicationDestinationPrefixes({"/app", "/topic"});。
否则，Spring不会将订阅消息转发给应用程序，只需将其转发到消息代理通道即可。