项目场景：

SpringBoot整合SpringSecurity，使用配置类进行登录名和密码配置

package com.example.helloworld;

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {


    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        BCryptPasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
        String password = passwordEncoder.encode("123");
        auth.inMemoryAuthentication().withUser("lucy").password(password).roles("admin");
    }

}

问题描述

报There is no PasswordEncoder mapped for the id "null"错误

原因分析：

因为在SpringBoot和SpringSecurity整合中，使用配置类进行用户名和密码配置时，需要在spring容器里有类型为PasswordEncoder的bean，要用

解决方案：

在配置类里添加

    @Bean
    PasswordEncoder password(){
        return new BCryptPasswordEncoder();
    }