Boot升级到2.6后出现BeanCurrentlyInCreationException

Question

将我的项目升级到 Spring Boot 后2.6.0，我​​在启动过程中遇到以下异常：

org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'webSecurityConfig': Requested bean is currently in creation: Is there an unresolvable circular reference?
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.beforeSingletonCreation(DefaultSingletonBeanRegistry.java:355) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:227) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:410) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.13.jar:5.3.13]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.13.jar:5.3.13]

但是，我的配置似乎符合 Spring 文档（HttpSecurity setup、AuthenticationManagerBuilder setup和PasswordEncoder setup）：

@Configuration
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
            .mvcMatchers("/presentations")
            .permitAll()
            .anyRequest()
            .authenticated()
            .and()
            .formLogin();
    }
    
    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
            .withUser("testuser")
            .password(encoder().encode("password"))
            .roles("READ");
    }

    @Bean
    public PasswordEncoder encoder() {
        return new BCryptPasswordEncoder();
    }
}

Answer 1

仔细查看我的实现，似乎@Autowired调用该方法的方法@Bean PasswordEncoder正在生成此问题（如果我从另一个定义方法中调用该方法，则不会发生这种情况@Bean）。

解决方案是将逻辑移至不同的@Configuration类：

@Configuration
public class UsersSetup {
    
    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth, PasswordEncoder encoder) throws Exception {
        auth.inMemoryAuthentication()
        .withUser("testuser")
        .password(encoder.encode("password"))
        .roles("READ");
    }
}

之所以在新的 Boot 版本中出现这种情况，是因为默认情况下 Boot 现在不再尝试自动打破依赖循环：

https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.6-Release-Notes#circular-references-prohibited-by-default

作为替代方案，我还可以通过在项目中包含以下应用程序属性来将此功能恢复为以前的行为：

spring.main.allow-circular-references=true