sprint data jpa 中Specification() 如何指定查询的字段而不是把整个表的所有字段都返回

Question

            List<Map<String, Object>> res = null;
            try{
                res = parkDao.findAll(new Specification() {
                    @Override
                    public Predicate toPredicate(Root root, CriteriaQuery criteriaQuery, CriteriaBuilder cb) {
                        List<Predicate> predicateList = new ArrayList<>();
                        criteriaQuery.multiselect();
                        if (!StringUtil.isEmpty(checkStatus)) {
                            predicateList.add(cb.equal(root.get("checkStatus"), checkStatus));
                        }
                        if (streetOfficeCode!=null) {
                            predicateList.add(cb.equal(root.get("streetOfficeCode"), streetOfficeCode));
                        }
                        if (communityCode!=null) {
                            predicateList.add(cb.equal(root.get("communityCode"), communityCode));
                        }
                        if (departmentCode!=null) {
                            predicateList.add(cb.equal(root.get("departmentCode"), departmentCode));
                        }
                        log.debug("predicateList--->"+predicateList);
                        Predicate[] pre = new Predicate[predicateList.size()];

                        criteriaQuery.where(predicateList.toArray(pre));

                        return cb.and(predicateList.toArray(pre));
                    }
                },new Sort(Sort.Direction.DESC,"id"));

这个代码构建了动态查询，但是查出了整个表的所有字段
我只需要其中的某些字段，该怎么办？

Answer 1

https://www.oschina.net/question/1175066_2140182