到UserDetailsServiceImpl中添加两个权限

return new User(username, password,
        //main.html,自定义访问权限时,缺少放行,在此处添加
        AuthorityUtils.commaSeparatedStringToAuthorityList("admin,normal,ROLE_abc,/main.html,/insert,/delete"));

位置截图:

在HTML中添加权限判断按键

通过权限判断:
<button sec:authorize="hasAuthority('/insert')">新增</button>
<button sec:authorize="hasAuthority('/delete')">删除</button>
<button sec:authorize="hasAuthority('/update')">修改</button>
<button sec:authorize="hasAuthority('/select')">查看</button>
<br>
通过角色判断:
<button sec:authorize="hasRole('abc')">新增</button>
<button sec:authorize="hasRole('abc')">删除</button>
<button sec:authorize="hasRole('abc')">修改</button>
<button sec:authorize="hasRole('abc')">查看</button>