如何返回自定义json文件而不是生成spring boot的默认json文件？

我有一个rest控制器进行授权：

@RestController
class AuthController {

    @PostMapping("/sign-up")
    fun signUp(@RequestBody signUpRequest: SignUpRequest): ResponseEntity<String> {
       some code here..
    }
}

当我使用JSON发出

/注册
post请求时：

{
    "role": "asdf",
    "email": "",
    "password": ""
}

它返回一个由spring boot生成的答案：

{
    "timestamp": "2020-02-12T05:45:42.387+0000",
    "status": 400,
    "error": "Bad Request",
    "message": "JSON parse error: Cannot deserialize value of type `foo.bar.xyz.model.Role` from String \"asdf\": not one of the values accepted for Enum class: [Student, Tutor]; nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `foo.bar.xyz.model.Role` from String \"asdf\": not one of the values accepted for Enum class: [Student, Tutor]\n at [Source: (PushbackInputStream); line: 3, column: 10] (through reference chain: foo.bar.xyz.model.SignUpRequest[\"role\"])",
    "path": "/sign-up"
}

问题是：如何返回自定义JSON而不是默认生成的JSON

我想返回我的自定义JSON，如：

{
  "result": "Invalid user data are given",
  "errors": [
    {
      "fieldName": "ROLE",
      "text": "Given role does not exist"
    },
    {
      "fieldName": "EMAIL",
      "text": "EMAIL is empty"
    }
  ]
}

我建议您创建ErrorContrller，生成自定义json映射作为响应。然后，当您在注册方法中发现错误时，调用ErrorContrllers方法。
你可以从这里找到信息。最后我找到了一个解决方案。您应该创建一个注释
@ControllerAdvice
的类，并创建一个注释
@ExceptionHandler
的方法

@ControllerAdvice
class HttpMessageNotReadableExceptionController {

    @ExceptionHandler(HttpMessageNotReadableException::class)
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    fun handleException(
        exception: HttpMessageNotReadableException
    ): PostSignUpResponseError {

        val errors = mutableListOf<PostSignUpResponseErrorItem>()

        errors.add(
            PostSignUpResponseErrorItem(
                fieldNamePost = "Role",
                text = "Given role does not exist"
            )
        )

        return PostSignUpResponseError(
            result = "Invalid user data are given",
            errors = errors
        )
    }
}

无论如何，我仍然不知道如何将这个东西附加到某个PostMapping方法。
网络上有很多例子。一个是
@ControllerAdvice
class HttpMessageNotReadableExceptionController {

    @ExceptionHandler(HttpMessageNotReadableException::class)
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    fun handleException(
        exception: HttpMessageNotReadableException
    ): PostSignUpResponseError {

        val errors = mutableListOf<PostSignUpResponseErrorItem>()

        errors.add(
            PostSignUpResponseErrorItem(
                fieldNamePost = "Role",
                text = "Given role does not exist"
            )
        )

        return PostSignUpResponseError(
            result = "Invalid user data are given",
            errors = errors
        )
    }
}

data class PostSignUpResponseError(
    val result: String,
    val errors: List<PostSignUpResponseErrorItem>
)

class PostSignUpResponseErrorItem(
    val fieldNamePost: PostSignUpRequestFieldName,
    val text: String
)