@Servicepublic class LMSService {    @Autowired    private BookInterface a;    private Collection<Books1> findBooks(){    List<Books1> books=new ArrayList<Books1>();    for(Books1 booke : a.findAll())    {        books.add(booke);    }    return books;} @Repositorypublic interface BookInterface extends CrudRepository<Books1,Long>{}a.findAll()方法給出了錯誤