Springboot验证在Kotlin中不起作用

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-validation'
    // 其他依赖项
}

data class User(
    @field:NotNull(message = "用户名不能为空")
    val username: String,
    @field:Size(min = 6, message = "密码长度至少为6位")
    val password: String
)

@Configuration
class WebMvcConfig : WebMvcConfigurer {
    override fun configureValidatingRepositoryEventListener(
        validatingListener: ValidatingRepositoryEventListener
    ) {
        validatingListener.addValidator("beforeCreate", validator())
        validatingListener.addValidator("beforeSave", validator())
    }

    @Bean
    fun validator(): LocalValidatorFactoryBean {
        return LocalValidatorFactoryBean()
    }
}

@ControllerAdvice
class GlobalExceptionHandler {
    @ExceptionHandler(MethodArgumentNotValidException::class)
    @ResponseBody
    fun handleValidationException(ex: MethodArgumentNotValidException): ResponseEntity<ErrorResponse> {
        val errors = ex.bindingResult.allErrors.map { it.defaultMessage }
        val response = ErrorResponse("参数验证失败", errors)
        return ResponseEntity(response, HttpStatus.BAD_REQUEST)
    }
}

data class ErrorResponse(val message: String, val errors: List<String>)