There is no PasswordEncoder mapped for the id "null"

 @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        //注入userDetailsService的实现类
        auth.userDetailsService(userDetailsService).passwordEncoder(new BCryptPasswordEncoder());
    }

为啥还在报错

https://blog.csdn.net/canon_in_d_major/article/details/79675033