1

我是java的新手。我试图为我的 API 实现更新方法。我想更新我的数据的某些字段。这是我的数据类：

public class Task implements Serializable {

    @Id
    private String id;
    private String task;
    private Boolean isCompleted;
    private String userId;
}

我的服务接口：

public interface TaskService {

    void create(Task task);

    Mono<Task> findById(String id);

    Flux<Task> findAll();

    Mono<Task> update(String Id, Task task);

    Mono<Void> delete(String id);
}

并为服务实施：

@Service
public class TaskServiceImpl implements TaskService {

    @Autowired
    TaskRepository taskRepository;

    public void create(Task task) {
        taskRepository.save(task).subscribe();
    }

    public Mono<Task> findById(String Id) {
        return taskRepository.findById(Id);
    }

    public Flux<Task> findAll() {
        return taskRepository.findAll();
    }

    public Mono<Task> update(String Id, Task task) {
//        System.out.println(taskRepository.findById(Id));
        return taskRepository.findById(Id)
                .switchIfEmpty(Mono.error(new Exception("TASK_NOT_FOUND")))
                .map(b -> {
                    task.setId(Id);
                    if (task.getTask() != null) task.setTask(task.getTask());
                    if (task.getIsCompleted() != null) task.setIsCompleted(task.getIsCompleted());
                    if (task.getUserId() != null) task.setUserId(task.getUserId());
                    return task;
                })
                .flatMap(taskRepository::save);
    }

    public Mono<Void> delete(String id) {
        return taskRepository.deleteById(id);
    }
}

我的控制器：

@RestController
public class TaskController {
    @Autowired
    private TaskService taskService;

    @PostMapping("/tasks")
    @ResponseStatus(HttpStatus.CREATED)
    public void create(@RequestBody Task task) {
        taskService.create(task);
    }

    @GetMapping("/tasks/{id}")
    public ResponseEntity<Mono<Task>> findbyId(@PathVariable("id") String Id) {
        Mono<Task> task = taskService.findById(Id);
        return new ResponseEntity<Mono<Task>>(task, task != null ? HttpStatus.OK : HttpStatus.NOT_FOUND);
    }

    @GetMapping(value = "/tasks")
    @ResponseBody
    public Flux<Task> findAll() {
        return taskService.findAll();
    }

    @PutMapping("/tasks/{id}")
    @ResponseStatus(HttpStatus.OK)
    public Mono<Task> update(@PathVariable("id") String Id, @RequestBody Task task) {
        return taskService.update(Id, task);
    }

    @DeleteMapping("/tasks/{id}")
    @ResponseStatus(HttpStatus.OK)
    public void delete(@PathVariable("id") String id) {
        taskService.delete(id).subscribe();
    }
}

和任务存储库：

@Repository
public interface TaskRepository extends ReactiveMongoRepository<Task, String> {
}

我在数据库中的数据：

{
    "id": "2",
    "task": "do",
    "isCompleted": true,
    "userId": "1"
}

我的请求正文：

{
    "userId": "2",
    "task": "updated"
}
}

我期望：

{
    "id": "2",
    "task": "updated",
    "isCompleted": true,
    "userId": "2"
}

但它回应：

{
    "id": "2",
    "task": "updated",
    "isCompleted": null,
    "userId": "2"
}

它用空值更新我在请求中的缺失值。如何更新数据中的特定值？

4

2 回答 2

1

问题在这里：

return taskRepository.findById(Id)
        .switchIfEmpty(Mono.error(new Exception("TASK_NOT_FOUND")))
        .map(b -> {
            task.setId(Id);
            if (task.getTask() != null) task.setTask(task.getTask());
            if (task.getIsCompleted() != null) task.setIsCompleted(task.getIsCompleted());
            if (task.getUserId() != null) task.setUserId(task.getUserId());
            return task;
        })

您完全忽略获取的Task（b实例）并task使用自己的值更新。你可能需要这样的东西：

.map(fetchedTask -> {
       if (task.getTask() != null) {
           fetchedTask.setTask(task.getTask());
       }
        return fetchedTask;
    })
于 2021-12-09T08:54:14.633 回答
0

在@Ikatiforis 之后，我已经解决了我的问题。

这是我的解决方案：

    public Mono<Task> update(String Id, Task task) {
        return taskRepository.findById(Id)
                .switchIfEmpty(Mono.error(new Exception("TASK_NOT_FOUND")))
                .map(fetchedTask  -> {
                    task.setId(Id);
                    if (task.getTask() != null 
                       {fetchedTask.setTask(task.getTask());}
                    if (task.getIsCompleted() != null) 
                       {fetchedTask.setIsCompleted(task.getIsCompleted());}
                    if (task.getUserId() != null) 
                       {fetchedTask.setUserId(task.getUserId());}
                    return fetchedTask;
                })
                .flatMap(taskRepository::save);
    }
于 2021-12-09T09:22:55.490 回答