java 差异删除 差异更新与删除

public boolean relation(Long projectId, List<BsMemberEntity> members) {
		//1)、获取原关联数据
		List<ProProjectAuthorEntity> oldList = this.findByProjectId(projectId);
		List<Long> oldMemberIds = oldList.stream().map(item -> {
			return item.getMemberId();
		}).collect(Collectors.toList());

		if (CollectionUtil.isNotEmpty(members)) {
			List<ProProjectAuthorEntity> newList = members.stream().map(item -> {
				ProProjectAuthorEntity entity;
				//是否是原有存在的人员
				if (CollectionUtil.contains(oldMemberIds, item.getId())) {
					entity = oldList.stream().filter(el -> el.getMemberId().equals(item.getId())).findFirst().get();
				} else {
					entity = new ProProjectAuthorEntity();
					entity.setProjectId(projectId);
					entity.setMemberId(item.getId());
					entity.setUserId(item.getUserId());
				}
				entity.setPower(item.getDescription());//此处使用人员描述字段代传

				return entity;
			}).collect(Collectors.toList());

			//1）、保存数据
			this.saveOrUpdateBatch(newList);

			//2）、去除差异数据
			Collection<Long> subtract = CollectionUtil.subtract(oldList, newList).stream().map(item -> {
				return item.getId();
			}).collect(Collectors.toList());
			this.removeBatchByIds(subtract);
		}else{
			this.removeBatchByIds(oldList);
		}
		return true;
	}