/**
     * 借书
     * @param bookDTO
     * @return
     */
    @Override
    @Transactional

    public boolean borrow(BookDTO bookDTO) {
        Book book = bookMapper.getBookById(bookDTO.getBookId());
        if (book.getNumber()-book.getStatus() > 0){
            if (book.getNumber()-book.getStatus() >= bookDTO.getNumber()){
                bookMapper.addStatus(bookDTO);
                BookUser history = bookMapper.getHistory(bookDTO);
                if (history != null){
                    bookDTO.setId(history.getId());
                    bookMapper.borrowHistory(bookDTO);
                }else{
                    bookMapper.saveHistory(bookDTO);
                }
                return true;
            }else{
                return false;
            }
        }
        return false;
    }