Spring Security出现There is no PasswordEncoder mapped for the id "null"

一、问题

输入账号密码日志窗口出现以下问题：

java.lang.IllegalArgumentException: There is no PasswordEncoder mapped for the id "null"
	at org.springframework.security.crypto.password.DelegatingPasswordEncoder$UnmappedIdPasswordEncoder.matches(DelegatingPasswordEncoder.java:250) ~[spring-security-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.security.crypto.password.DelegatingPasswordEncoder.matches(DelegatingPasswordEncoder.java:198) ~[spring-security-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter$LazyPasswordEncoder.matches(WebSecurityConfigurerAdapter.java:592) ~[spring-security-config-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.security.authentication.dao.DaoAuthenticationProvider.additionalAuthenticationChecks(DaoAuthenticationProvider.java:90) ~[spring-security-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	....

二、分析

项目开发使用的 Spring Boot 版本是2.2.2.RELEASE，对应的Spring Security 版本是5.2.1。
在Spring Security 5.0之前，PasswordEncoder 的默认值为 NoOpPasswordEncoder 既表示为纯文本密码，在实际的开发过程中 PasswordEncoder 大多数都会设值为 BCryptPasswordEncoder ，所以需要对密码进行加密。

三、解决

passwordEncoder()添加对应的密码编码方式，同时使用new BCryptPasswordEncoder().encode("xxx")对密码加密，不然会出现Encoded password does not look like BCrypt的错误警告。

@Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth
                .inMemoryAuthentication()
                    .withUser("admin1").password(new BCryptPasswordEncoder().encode("admin1")).roles("ADMIN", "USER") // 管理员，同事具有 ADMIN,USER权限，可以访问所有资源
                .and()
                    .withUser("user1").password(new BCryptPasswordEncoder().encode("user1")).roles("USER")// 普通用户，只能访问 /product/**
                .and()
                  .passwordEncoder(new BCryptPasswordEncoder());
    }