我正在使用Java Springboot和Angular 7开发聊天应用程序。我在spring Boot 和angular中使用事件。我尝试在spring Boot 中生成事件，以便angular侦听事件。然而，我得到以下错误：

Resolved [org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation]

下面是我在springboot中的控制器代码：

@CrossOrigin("*")
@RestController
@RequestMapping("/chat")
public class MessageController {

@Autowired
MessageService messageService;

@Autowired
private ApplicationEventPublisher applicationEventPublisher;

private static final Logger logger = LoggerFactory.getLogger(MessageController.class);

@PostMapping(consumes = "application/json", produces = "application/json")
public GenericApiResponse<Map<String, Object>>message(@RequestBody MessageRequest req) {
    logger.info("MessageController:: messagemethod [POST] /chat");
    GenericApiResponse<Map<String, Object>> responseObj = new GenericApiResponse<>();
    Object returnValue = new Object();
    try {
        returnValue = messageService.translateText(req);
    } catch (Exception e) {
        e.printStackTrace();
        logger.error("EXCEPTION: "+e.getStackTrace().toString());
        responseObj.setStatus(Constants.ERROR);
        responseObj.setMessage("Internal Server Error");
    }
    Map<String, Object> resMap = new HashMap<>();
    resMap.put("result", returnValue);
    resMap.put("sender", req.getSender());
    responseObj.setResponseObject(resMap);
    responseObj.setStatus(Constants.SUCCESS);

    MessageEvent messageEvent = new MessageEvent(this,"eventName", responseObj);
    applicationEventPublisher.publishEvent(messageEvent);

    return responseObj;
}

我不知道问题是什么，以及如何解决它。请帮我解决这个问题。提前感谢：）