状态“：500，”错误“：”内部服务器错误（Spring Boot和cURL）

Question

我想保存一条消息，当我运行curl请求时-

curl -H "Content-Type: application/json" -X POST -d "{\"time\": \"2019-12-27T09:50:02.000+0000\", \"unread\": true, \"message\": \"asd\", \"from\": \"John\"}" localhost:8080/api/save

我在cmd中出错

{“时间戳”：“ 2020-01-05T04：36：33.192 + 0000”，“状态”：500，“错误”：“内部服务器错误”，“消息”：“无可用消息”，“跟踪” “：” java.lang.NullPointerException \ r \ n \ tat org.vaadin.marcus.spring.service.impl.MessageServiceImpl.add（MessageServiceImpl.java:45）\ r \ n \ tat org.vaadin.marcus.spring。 service.impl.MessageServiceImpl $$ FastClassBySpringCGLIB $$ 2d73a7c.invoke（）\ r \ n \ tat

我的代码

@Service
@Transactional
public class MessageServiceImpl implements MessageService {
    private final MessageRepository repository;
    private final PageRequest lastRequest;

    private List<Long> chekedMessages = new ArrayList<>();


    @Autowired
    public MessageServiceImpl(MessageRepository repository) {
        this.repository = repository;
        lastRequest = new PageRequest(0, 10, Sort.Direction.DESC, "id");
    }

    @Override
    public MessageStatus add(@RequestBody  Message message) {
        MessageStatus status = null;
        try {
            repository.save(message);
            status.setMessage("Message Saved");
        }
        catch (Exception e) {
            status.setMessage("Message not saved - " + e);
        }
        return status;
    }

    @Override
    public List<Message> getAllMessages() {
        return repository.findAll();
    }

    @Override
    public List<Message> getLast() {
        List<Message> result = repository.findAll(lastRequest).getContent();

        return result.stream()
                .sorted(Comparator.comparingLong(Message::getId))
                .collect(Collectors.toList());
    }

    @Override
    public List<Message> getUnreadById(long id) {
        return repository.getUnreadById(id);
    }



    @Override
    public String getUnreadMessages() {
        List<Message> out = new ArrayList<>();
        List<Message> unchekedMessages = repository.findAll();
        for (Message message: unchekedMessages) {
            if (!chekedMessages.contains(message.getId())) {
                chekedMessages.add(message.getId());
                out.add(message);
            }
        }
        return new Gson().toJson(out);
    }

    @Override
    public void updateMessage(long id, Message message) {
        if (repository.findById(id).isPresent()) {
            message.setId(id);
            repository.save(message);
        }
    }
}

其他控制器

public class RestController {

    @Autowired
    TimerTask timerTask;

    @Resource
    private final MessageService messageService;

    public RestController(MessageService messageService) {
        this.messageService = messageService;
    }

    @PostMapping("/api/save")
    public MessageStatus saveMessage(@RequestBody Message chatMessage) {
        return messageService.add(chatMessage);
    }

    @GetMapping("/api/last")
    public String getLasts() {
        return new Gson().toJson(messageService.getLast());
    }

    @GetMapping("/api/unread")
    public void getUnreadMessages() {

        timerTask.run();
    }

    @GetMapping("/api/unread/{id}")
    public List<Message> getUnreadById(@PathVariable ("id") long id) {
        return messageService.getUnreadById(id);
    }

Github-https://github.com/fallen3019/vaadin-chat