jpa Specification动态查询分页-实例

淩亂°似流年 2022-05-18 08:46 350阅读 0赞

作者：LoveEmperor-王子様

1.Specification接口中定义了如下一个方法：

Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb);

一、动态查询分页应用代码示例：  
controller接口：

@PostMapping("/xx-xx-xx")
        @Timed
        public Page<InvoiceInfo> getAllInvoiceInfos(@Valid @RequestBody InvoiceListVo vo) throws Exception{
            log.debug("REST request to get all InvoiceInfos");
    
            return invoiceInfoService.findByCondition(vo);
        }

service方法：

public Page<InvoiceInfo> findByCondition(InvoiceListVo vo) {
            Pageable pageable = new PageRequest(vo.getPageNumber(), vo.getPageSize(), Sort.Direction.ASC, "id");
    
            Page<InvoiceInfo> page = this.invoiceInfoRepository.findAll(getCondition(vo), pageable);
    
            return page;
        }

private Specification<InvoiceInfo> getCondition(InvoiceListVo vo){
            Specification<InvoiceInfo> sp = new Specification<InvoiceInfo>() {
                /** * @param root root参数是我们用来对应实体的信息的。 * @param query * @param cb criteriaBuilder可以帮助我们制作查询信息。 * @return */
                @Override
                public Predicate toPredicate(Root<InvoiceInfo> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
                    // 创建 Predicate
                    Predicate predicate = cb.conjunction();
                    // 组装条件
                    if(!vo.getPhone().equals("0")){
    // predicate.add(cb.equal(root.get("phone"), vo.getPhone()));
                        predicate.getExpressions().add(cb.equal(root.get("phone"), vo.getPhone()));
                    }
                    if(0 != vo.getTitleType()){
                        predicate.getExpressions().add(cb.equal(root.get("titleType"), vo.getTitleType()));
                    }
                    if(null != vo.getInvoiceTitle()){
                        predicate.getExpressions().add(cb.equal(root.get("invoiceTitle"), "%"+vo.getInvoiceTitle()+"%"));
                    }
                    return predicate;
                }
    
            };
            return sp;
        }

JpaRepository：

@SuppressWarnings("unused")
    @Repository
    public interface InvoiceInfoRepository extends JpaRepository<InvoiceInfo, Long>,JpaSpecificationExecutor<InvoiceInfo> { 
    }

二、动态查询不分页：

public List<InvoiceInfo> findByCondition(InvoiceListVo vo){
            List<InvoiceInfo> resultList = null;
            Specification querySpecifi = new Specification<InvoiceInfo>() {
                @Override
                public Predicate toPredicate(Root<InvoiceInfo> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
    
                    List<Predicate> predicates = new ArrayList<>();
                    if(!vo.getPhone().equals("0")){
                        predicates.add(criteriaBuilder.equal(root.get("phone"), vo.getPhone()));
                    }
                    if(0 != vo.getTitleType()){
                        predicates.add(criteriaBuilder.equal(root.get("titleType"), vo.getTitleType()));
                    }
                    if(null != vo.getInvoiceTitle()){
                        predicates.add(criteriaBuilder.equal(root.get("invoiceTitle"), "%"+vo.getInvoiceTitle()+"%"));
                    }
                    return criteriaBuilder.and(predicates.toArray(new Predicate[predicates.size()]));
                }
            };
            resultList =  this.invoiceInfoRepository.findAll(querySpecifi);
            return resultList;
        }

三、只分页查询：

@Transactional(readOnly = true)
        public Page<InvoiceInfo> findAll(Integer page,Integer size) {
            Pageable pageable = new PageRequest(page, size, Sort.Direction.ASC, "id");
            return invoiceInfoRepository.findAll(pageable);
    
        }