class StorageJetCache extends SimpleJpaRepository<E,PK> implements IStorage<PK,E> {

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void update(E entity) {
        PK id = entity.getId();
        Preconditions.checkNotNull(id,"id不能为null");
        CacheGetResult<E> cacheGetResult = cache.GET(id);
        if (cacheGetResult.isSuccess()){
            E entityFromCache = cacheGetResult.getValue();
            // 缓存中缓存了其null值，说明数据库中没有
            if (entityFromCache == null) {
                throw new EntityNotFoundException("数据库中不存在该实体，先create一下？");
            }
            // 缓存中有，说明数据库中也有
            else {
                executeUpdate(entity);
            }
        }else {
            if (exists(entity.getId())){
                executeUpdate(entity);
            }else {
                throw new EntityNotFoundException("数据库中不存在该实体，先create一下？");
            }
        }
    }

    public  StorageJetCache(JpaEntityInformation<E, ?> entityInformation, EntityManager entityManager);

}