java 48 lines · 8 steps

Real-time chat over STOMP WebSockets in Spring

A Spring WebSocket config plus a controller that routes STOMP messages and broadcasts presence updates to subscribed clients.

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Spring Intermediate websockets stomp messaging pub-sub real-time
1@Configuration
2@EnableWebSocketMessageBroker
3public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
4 
5 @Override
6 public void registerStompEndpoints(StompEndpointRegistry registry) {
7 registry.addEndpoint("/ws")
8 .setAllowedOriginPatterns("https://app.example.com")
9 .withSockJS();
10 }
11 
12 @Override
13 public void configureMessageBroker(MessageBrokerRegistry registry) {
14 registry.setApplicationDestinationPrefixes("/app");
15 registry.enableSimpleBroker("/topic", "/queue");
16 registry.setUserDestinationPrefix("/user");
17 }
18}
19 
20@Controller
21public class ChatController {
22 
23 private final SimpMessagingTemplate messagingTemplate;
24 
25 public ChatController(SimpMessagingTemplate messagingTemplate) {
26 this.messagingTemplate = messagingTemplate;
27 }
28 
29 @MessageMapping("/rooms/{roomId}/send")
30 public void handleMessage(@DestinationVariable String roomId,
31 @Payload ChatMessage message,
32 Principal principal) {
33 var outgoing = new ChatMessage(
34 principal.getName(),
35 message.content(),
36 Instant.now());
37 
38 messagingTemplate.convertAndSend("/topic/rooms/" + roomId, outgoing);
39 }
40 
41 @EventListener
42 public void onDisconnect(SessionDisconnectEvent event) {
43 var accessor = StompHeaderAccessor.wrap(event.getMessage());
44 String user = accessor.getUser() != null ? accessor.getUser().getName() : "unknown";
45 messagingTemplate.convertAndSend("/topic/presence",
46 Map.of("user", user, "status", "OFFLINE"));
47 }
48}
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1A message broker with destination prefixes cleanly separates client-to-server calls from server-to-client broadcasts.
  2. 2SimpMessagingTemplate lets any Spring bean push messages to subscribers without holding a socket reference.
  3. 3Listening for lifecycle events like disconnects turns raw connection state into meaningful presence signals.

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