如何避免在抛出异常时延迟返回值的NPE？

Question

我现在和索纳库贝有矛盾。我有一个validator服务（它检查我通过API接收的DTO是否在Double和String对象（不是原语）中不包含空值）。

        validateNotNull(employeeResponseDTO.getGetSalary(), "Salary");
        validateNotNull(employeeResponseDTO.getBonus(), "Bonus");
        validateNotNull(employeeResponseDTO.getAge, "Age");

    }

    private void validateNotNull(final Object o, final String fieldName) {
        if (o == null) {
            throw new HRServiceException(MessageFactory.getExceptionByMessage(ERROR_TYPE, fieldName));
        }
    }
}

    public EmployeeResponseDTO sendEmployeeRequest(EmployeeRequestDTO employeeRequestDTO, HttpHeaders headers) {
        HttpEntity<EmployeeRequestDTO> entity = new HttpEntity<>(employeeDTO, prepareHeaders(requestHeaders));
        ResponseEntity<EmployeeRequestDTO> response = restTemplate.postForEntity(employeeServiceURL, entity, EmployeeResponseDTO.class);
        EmployeeResponseDTO employeeResponseDTO = new EmployeeResponseDTO();
        if (response.hasBody() && response.getBody() != null) {
            employeeResponseDTO = response.getBody();
            logger.info(SystemMessages.RESPONSE_RECEIVED);
            employeeValidator.validateEmployee(employeeResponseDTO);
        }
        return employeeResponseDTO;
    }

    public EmployeeResponseDTO sendEmployeeRequest(EmployeeRequestDTO employeeRequestDTO, HttpHeaders headers) {
        HttpEntity<EmployeeRequestDTO> entity = new HttpEntity<>(employeeDTO, prepareHeaders(requestHeaders));
        ResponseEntity<EmployeeRequestDTO> response = restTemplate.postForEntity(employeeServiceURL, entity, EmployeeResponseDTO.class);
        EmployeeResponseDTO employeeResponseDTO = response.getBody(); 
        if (employeeResponseDTO != null) {
            logger.info(SystemMessages.RESPONSE_RECEIVED);
            employeeValidator.validateEmployee(employeeResponseDTO);
        }
        return employeeResponseDTO;
    }

Answer 1

更改：

if (response.hasBody() && response.getBody() != null) {
    employeeResponseDTO = response.getBody();
    logger.info(SystemMessages.RESPONSE_RECEIVED);
    employeeValidator.validateEmployee(employeeResponseDTO);
}

致：

if (response.hasBody() && response.getBody() != null) {
    employeeResponseDTO = response.getBody();
    logger.info(SystemMessages.RESPONSE_RECEIVED);
    if(employeeValidator == null)
        throw new NullPointerException();
    employeeValidator.validateEmployee(employeeResponseDTO);
}