我的问题是我有一个名为phonebillpaymentdto的dto，它有一个用@notnull注解的phonenumber字段。当我用modelmapper将这个电话号码为空的dtoMap到phonebillpayment实体时，它不会抛出异常。
当notnull值设置为null时，如何使其抛出异常？
我的课在这里；

public class PhoneBillPaymentTransactionDTO extends PaymentTransactionDTO {

    @NotNull
    private String phoneNumber;

    public PhoneBillPaymentTransactionDTO() {

    }

    public PhoneBillPaymentTransactionDTO(@NotNull BigDecimal amount, @NotNull TransactionTypes type,
            @NotNull String payeeAccountNumber, @NotNull String owner, @NotNull String phoneNumber) {
        super(amount, type, payeeAccountNumber, owner);
        this.phoneNumber = phoneNumber;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

}

控制器：

@PostMapping(path = "/payment/{accountNumber}")
public ResponseEntity<TransactionStatus> payment(@PathVariable String accountNumber,
        @Valid @RequestBody PaymentTransactionDTO paymentTransactionDTO) throws InsufficientBalanceException {

    return new ResponseEntity<>(
            accountService.payment(accountNumber, MapperUtil.createTrxByTrxDTO(paymentTransactionDTO)),
            HttpStatus.OK);
}

Map器工具：

public final class MapperUtil {

    private MapperUtil() {

    }

    private static final ModelMapper mapper = new ModelMapper();

    public static final Transaction createTrxByTrxDTO(TransactionDTO dto) {
        if (dto.getType() == TransactionTypes.DEPOSIT) {
            return mapper.map(dto, DepositTransaction.class);
        }
        if (dto.getType() == TransactionTypes.WITHDRAWAL) {
            return mapper.map(dto, WithdrawalTransaction.class);
        }
        if (dto.getType() == TransactionTypes.PAYMENT) {
            return mapper.map(dto, PaymentTransaction.class);
        }
        if (dto.getType() == TransactionTypes.PHONEBILLPAYMENT) {
            mapper.getConfiguration().setPropertyCondition(Conditions.isNotNull());
            return mapper.map(dto, PhoneBillPaymentTransaction.class);
        }
        throw new UnsupportedTransactionTypeException();
    }

}