使用Spring boot WebFlux、Spring Data MongoDB Reactive和ReactiveM

Question

我是java新手。我尝试为我的API实现更新方法。我想更新我的一些数据字段。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);
}

并实现服务：

@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"
}
}

我预期：

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

但它回应道：

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

它用空值更新我在请求中丢失的值。如何更新数据中的特定值？

Answer 1

问题就在这里：

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;
})

您完全忽略提取的Task(b实例(，并使用其自己的值更新task。你可能需要这样的东西：

.map(fetchedTask -> {
if (task.getTask() != null) {
fetchedTask.setTask(task.getTask());
}
return fetchedTask;
})

Answer 2

继@Ikatiforis之后，我解决了我的问题。

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);
}