how to use Optional isPresent() properly

Issue

I have this method:

public String updateShift(ShiftsDTO shiftsDTO){

    Optional<Shifts> optionalPreUpdateShift = shiftsRepository.findById(shiftsDTO.getId());

    if (optionalPreUpdateShift.isPresent()) {
        if (!shiftsRepository.existsByShiftStartAndShiftEnd(shiftsDTO.getShiftStart(), shiftsDTO.getShiftEnd())) {
            Shifts preUpdateShift = optionalPreUpdateShift.get();
            shiftsMapper.mapShiftFromDto(shiftsDTO,preUpdateShift);
            shiftsRepository.save(preUpdateShift);
            return " Shift updated successfully";
        } else {
            throw new ShiftAlreadyExistsException("An existing shift already covers this period");
        }
    } else {
        throw  new ShiftNotFoundException("This shift doesn't exist");
    }
}

This method is for updating shifts in a shop. I didn't use isPresent() before and now tried to implement it but the code looks incredibly dirty and unreadable. What are the correct ways to use Optional in such cases?

Solution

One way to keep yourself from indenting like this: Change your first line

Optional<Shifts> optionalPreUpdateShift = ShiftsRepository.findById(shiftsDTO.getId());

to instead unwrap the optional right away:

Shifts shifts = ShiftsRepository.findById(shiftsDTO.getId())
                .orElseThrow(()-> new ShiftNotFoundException("This shift doesn't exist");

Answered By - hpr