spring-data-jpa动态条件查询

//获取动态条件的集合List<Long> list = new ArrayList<Long>();
        Long sysUserId = currentUser.getSysUserId();
        if (sysUserId != null) {
            SysUser sysUser = sysUserRepository.findOne(sysUserId);
            if (sysUser != null) {
                String groupItemIds = sysUser.groupItemIds();
                if (groupItemIds != null && !groupItemIds.isEmpty()) {
                    String[] str = StringUtils.split(groupItemIds,",");
                    for (String s : str) {
                        if (s != null && !s.isEmpty() && s != "") {
                            list.add(Long.valueOf(s));
                        }
                    }
                }
            }
        }

//封装Specification查询条件Specification<Goods> spec = (root, query, cb) -> {
            List<Predicate> predicates = new ArrayList<Predicate>();

            List<Predicate> preList = new ArrayList<Predicate>();
            if (list != null && list.size()>0) {
                    preList.add(root.<Long>get("groupItemId").in(list));
               }
           if (sysUserId != null) {
                 Predicate predicate = cb.equal(root.get(Goods_.crtUserId), sysUserId);
                 preList.add(predicate);
           }
                Predicate p = cb.or(preList.toArray(new Predicate[preList.size()]));
                predicates.add(p);

            if (!predicates.isEmpty()) {
                return cb.and(predicates.toArray(new Predicate[0]));
            } else {
                return null;
            }
        };

        Page<Goods> pageresult = goodsRepository.findAll(spec, pageable);