Hands-On Reactive Programming in Spring 5

Exposing the SSE endpoint

The next step requires adding the TemperatureController class with the @RestController annotation, which means that the component is used for HTTP communication, as shown in the following code:

@RestControllerpublic class TemperatureController {   private final Set<SseEmitter> clients =                          // (1)      new CopyOnWriteArraySet<>();                       @RequestMapping(      value = "/temperature-stream",                                // (2)      method = RequestMethod.GET)   public SseEmitter events(HttpServletRequest request) {           // (3)      SseEmitter emitter = new SseEmitter();                        // (4)      clients.add(emitter);                                         // (5)      // Remove emitter from clients on error or disconnect      emitter.onTimeout(() -> clients.remove(emitter));             // (6)      emitter.onCompletion(() -> clients.remove(emitter));          // (7)       return ...