spring data JPA 中的多属性排序---养老院管理系统涉及技术整理

Posted 2020-10-05 Mark-先生

在此介绍我所用的一种方式：

第一步，引包

import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Order;

第二步，service方法代码

　　@Override
    public Page<TurnOverRecord> findAll(Integer pageNum, Integer pageSize, TurnOverRecord turnOverRecord) {
//先按isTurnOver从小到大升序，再按turnOverTime升序
        List< Order> orders=new ArrayList< Order>();
        orders.add( new Order(Sort.Direction. ASC, "isTurnOver"));
        orders.add( new Order(Sort.Direction. ASC, "turnOverTime"));
        Pageable pageable= new PageRequest(pageNum - 1, pageSize, new Sort(orders));

        Specification<TurnOverRecord> specification = new Specification<TurnOverRecord>() {
            @Override
            public Predicate toPredicate(Root<TurnOverRecord> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
                Predicate predicate = cb.conjunction();
                //单属性排序
//                query.orderBy(cb.asc(root.get("isTurnOver")));
//                query.orderBy(cb.desc(root.get("id")));
//                query.groupBy(root.get("id"));
                query.distinct(true);
                //判断是否有条件
                predicate.getExpressions().add(cb.equal(root.get("flag"), 1));
                if (turnOverRecord != null) {
                    if (StringUtil.isNotNull(turnOverRecord.getMemberId())
                            && StringUtil.isNotNullAndZero(turnOverRecord.getMemberId().getId())
                            ) {
                        predicate.getExpressions().add(cb.equal(root.get("memberId").get("id"), turnOverRecord.getMemberId().getId()));
                    }
                    if (StringUtil.isNotNull(turnOverRecord.getMemberId())
                            && StringUtil.isNotNullAndBlank(turnOverRecord.getMemberId().getName())
                            ) {
                        predicate.getExpressions().add(cb.like(root.get("memberId").get("name"), "%"+turnOverRecord.getMemberId().getName().trim()+"%"));
                    }
                    if (StringUtil.isNotNull(turnOverRecord.getCreator())
                            && StringUtil.isNotNullAndBlank(turnOverRecord.getCreator().getName())) {
                        predicate.getExpressions().add(cb.like(root.get("creator").get("name"), "%"+turnOverRecord.getCreator().getName().trim() + "%"));
                    }
                }
                return predicate;
            }
        };
        return turnOverRecordDao.findAll(specification, pageable);
    }