解决：java.lang.IllegalArgumentException: There is no PasswordEncoder mapped for the id “null“

在使用springboot + spring security，使用内存用户登录时后台报错：java.lang.IllegalArgumentException: There is no PasswordEncoder mapped for the id "null"

Spring boot 2.6.1    spring security 5.6.0   jkd8 

 从spring security 5.X开始，需要提供一个PasswordEncorder的实例，否则后台会报错

自己写一个 PasswordEncoder 实例

   @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
                .withUser("123").password("123").roles("admin")
                .and()
                .withUser("321").password("321").roles("user");
    }

    @Bean
    PasswordEncoder passwordEncoder() {
        return NoOpPasswordEncoder.getInstance();
    }

重启：