Question

这是使用和初始化Optional变量的正确方法吗。.当我调用calculateAnnualCalculationTotal时，在所有这些变量上都收到一个错误“变量可能未初始化”。如果保险，我想在AnnualCalculationSummaryDto中使用这些变量.product不是abc或def，否则试图在AnnualCalculationSummaryDto中设置的这三个字段应保持为null ..

                 Optional<CalculatedPaymentsDto> calculatedPayments  ;
        Optional<PaidPaymentsDTO> paidPayments  ;
        Optional<CreatePaymentResponseDto> payment ;

        if (!insurance.getProduct().equalsIgnoreCase("abc") && !insurance.getProduct().equalsIgnoreCase("def")) {

            int totalAnnualCalculationSum = calculateAnnualCalculationTotal(insurance, requestDto.getAnnualCalculationYear(), calculatedPayments, paidPayments);
            payment = Optional.ofNullable(createPayment(getCreatePaymentRequestDto(insurance, calculatedPayments.get(), totalAnnualCalculationSum, requestDto.getAnnualCalculationYear())));
        }

        AnnualCalculationSummaryDto annualCalculationSummaryDto = new AnnualCalculationSummaryDto();
        if(calculatedPayments.isPresent() && paidPayments.isPresent() && payment.isPresent()){
            annualCalculationSummaryDto.setCalculatedPaymentsDto(calculatedPayments.get());
            annualCalculationSummaryDto.setPaidPaymentsDTO(paidPayments.get());
            annualCalculationSummaryDto.setPayments(payment.get());
        }
     annualCalculationSummaryDto.setParam1(inr.getProduct());
     annualCalculationSummaryDto.setParam2(requestDto.getTotal());
     annualCalculationSummaryRepository.save(annualCalculationSummaryDto);

........ ............. ..............

private int calculateAnnualCalculationTotal (Insurance insurance , int year , Optional<CalculatedPaymentsDto> calculatedPayments , Optional<PaidPaymentsDTO> paidPayments) {

        calculatedPayments = Optional.ofNullable(paymentService.getCalculatedPayments(insurance.getId(), year));

        paidPayments = Optional.ofNullable(paymentService.getPaidPayments(insurance.getInsuranceYears(), year));
       totalSum = calculatedPayments.get().getParam1()+ paidPayments.get().getParam2();
.....
}

或者有更好的方法来写这个..

Answer 1

付款是在if子句中初始化的，因此，不保证在if子句后使用它时会对其进行初始化。
要将Optional初始化为“ null”：Optional<T> myOptional = Optional.empty();

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