此驗證程序檢查數據庫中登錄名的唯一性。在第一次檢查時，即當他進入 counterlord 時，一切都很好。但它在保存到數據庫時也有效。但不幸的是，負責檢查登錄唯一性的服務不能@Autowire。問題是什么？是否應該檢查 2 次？class ValidatorUniqueLogin : ConstraintValidator<UniqueLogin, String> {    @Autowired val serviceAccaunt: ServiceAccaunt? = null // this null    override fun initialize(annotation: UniqueLogin?) {}    override fun isValid(login: String, ctx: ConstraintValidatorContext): Boolean {        return serviceAccaunt!!.isHaveLogin(login)    }}@Documented@Constraint(validatedBy = [ValidatorUniqueLogin::class])@Target(AnnotationTarget.FIELD)@Retention(RetentionPolicy.RUNTIME)annotation class UniqueLogin(        val message: String = "{text.error.login.not.unique}",        val groups: Array<KClass<*>> = [],        val payload: Array<KClass<out Payload>> = [])@Serviceclass ServiceAccaunt(@Autowired val repoAccaunt: RepoAccaunt) {    fun isHaveLogin(login: String): Boolean {        val count = repoAccaunt.countByLogin(login)        return !(count > 0)    }}@IsAnonymous    @PostMapping("/reg")    fun reg(            model: Model,            @Valid @ModelAttribute("accaunt") accaunt: Accaunt,            bindingResult: BindingResult    ): String {        if (accaunt.roles.isNotEmpty()) {            val acessRoles = serviceRole.findRolesForRegistration()            for (role: Role in accaunt.roles) if (!acessRoles.contains(role)) accaunt.roles.minus(role)        }