Java 有人能纠正这个SQL语法异常吗

错误：com.mysql.jdbc.exceptions.MySQLSyntaxErrorException：您的SQL语法有错误；查看与MySQL服务器版本对应的手册，以了解第1行“index='2'附近要使用的正确语法

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索引

是一个关键字，如果将其用作列名，请尝试使用倾斜转义。（`）

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索引是一个保留关键字。不要用作列名。。。。

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
{   
    String index= request.getParameter("Index");
    index=index.trim();

    System.out.println(index);

    PrintWriter out = response.getWriter();
    try 
    {
        Class.forName("com.mysql.jdbc.Driver");
        Connection dbConnection=DriverManager.getConnection("jdbc:mysql://localhost:3306/smb","root","");
        System.out.println(" Connected ");

        PreparedStatement ps=(PreparedStatement) dbConnection.prepareStatement(" select index from books where index=? ");
        System.out.println(" Prepared ");

        try
        {           
            ps.setString(1, index);         
            ResultSet rs = ps.executeQuery();               

            String keysInDb;
            keysInDb="";

            while(rs.next())
            {
                keysInDb=rs.getString(1);
                System.out.println(keysInDb);
            }

            dbConnection.close();

        }
        catch (Exception e) 
        {
            System.out.println("ERROR : "+e);
        }



    }
    catch (Exception e) 
    {
        out.print(e);
    }



}

....
PreparedStatement ps=(PreparedStatement) dbConnection.prepareStatement(" select `index` from books where `index`=? ");
....