SseEmitter onCompletion回调方法未执行原因

SseEmitter  onCompletion方法未执行原因：

  @GetMapping("/sseTest/{id}")
    public SseEmitter testSSE(@PathVariable Long id) throws IOException {
        System.out.println("===================");
        SseEmitter sseEmitter = getSseEmitter(id);
        AIContextThreadHolder.init("init - 1");

        sseEmitter.onCompletion(() -> {
            SSE_CACHE.remove(id);
            System.out.println("====onCompletion = " + AIContextThreadHolder.get());
        });
        sseEmitter.onTimeout(() -> {
            SSE_CACHE.remove(id);
            System.out.println("==onTimeout = " + AIContextThreadHolder.get());
        });

        sseEmitter.onError((e) -> {
            SSE_CACHE.remove(id);
            System.out.println("===onError = " + AIContextTh