java如何简单地检查请求体是否为空或请求体是否有空字段？

Question

嗨，我有一个接受POST请求的控制器

请求正文可以是空的，也可以带有空字段的正文：即或{}

@RestController
public class UserController {
    @Autowired
    private UserService UserService;
    @RequestMapping(value = "/tree", method = POST,consumes = MediaType.APPLICATION_JSON_VALUE)
    public List<ResponseUser> controller(@RequestBody(required=false) UserDataRequest request) {
        return UserService.send(request);
    }
}

我的服务定义如下：

1. 检查主体是否为空，即null
2. 逐个检查字段是否为空
3. 如果字段为空，则再次执行步骤1

@Service
public class UserService {

    @Autowired
    private RestTemplate restTemplate;

    private ResponseEntity<List<ResponseUser>> responseEntity;

    public List<ResponseUser> send(UserDataRequest data){


        //empty body == null
    if(data == null ) {
           // return list1 of type ResponseUser
        }
    else{

       //Check for the fields are present are not
        Optional<String> id = Optional.ofNullable(data.getid());
        Optional<String> search = Optional.ofNullable(data.getsearch());

        //if id is present 
        if (id.isPresent()) {
            // return list2 of type ResponseUser

        }

        //if search is present 
        else if(search.isPresent()){
        // return list3 of type ResponseUser

            }

        else {
        // return list1 of type ResponseUser
        }
    }
    return responseEntity.getBody();
    }
}

我想知道如何不再重复同样的事情？有什么有效的方法吗

Answer 1

向Pojo类添加验证注释

public class UserDataRequest {
@NotNull
private String id;

@NotNull
private String search;
}

更新post方法以使用此验证

 public List<ResponseUser> send(@Valid UserDataRequest data){}