如何仅添加一个数据？

Question

@PutMapping("/api/cricketer/{id}")
public ResponseEntity<Cricketer> updateCricketer(@PathVariable("id") Long id, @RequestBody Cricketer cricketer) {
    Cricketer cCricketer = cricketerService.findById(id);
    cCricketer.setCountry(cricketer.getCountry());
    cCricketer.setName(cricketer.getName());
    cCricketer.setHighestScore(cricketer.getHighestScore());
    cricketerRepository.save(cCricketer);
    return new ResponseEntity<Cricketer>(cricketer, HttpStatus.OK);
}

Hello everyone. When I try to update a data on updateCricketer method, it updates the data as I entered. But other datas turn as null. Does anyone know how can I solve that problem?

Answer 1

Do a null check before setting values.

@PutMapping("/api/cricketer/{id}")
public ResponseEntity<?> updateCricketer(@PathVariable("id") Long id, @RequestBody Cricketer cricketer) {
    Cricketer cCricketer = cricketerService.findById(id);
    if(Objects.nonNull(cCricketer)) {
        cCricketer.setCountry(Objects.isNull(cricketer.getCountry()) ? cCricketer.getCountry() : cricketer.getCountry());
        cCricketer.setName(Objects.isNull(cricketer.getName()) ? cCricketer.getName() : cricketer.getName());
        cCricketer.setHighestScore(Objects.isNull(cricketer.getHighestScore()) ? cCricketer.getHighestScore() : cricketer.getHighestScore());
        // Do same to the rest of the fields

        cricketerRepository.save(cCricketer);

        return new ResponseEntity<>(cricketer, HttpStatus.OK);
    } else {
        return new ResponseEntity<>("No cricketer Found!", HttpStatus.OK);
    }
}

Answer 2

Another solution for this is to use data transfer objects and an object mapper which will take care of the null check depending on the strategy that you decide.

http://mapstruct.org/documentation/stable/reference/html/#mapping-result-for-null-arguments