将 Boot 升级到 2.6 后出现 BeanCurrentlyInCreationException

Question

将我的项目升级到 Spring Boot 2.6.0 后，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]

不过，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，似乎调用 @Bean PasswordEncoder 方法的 @Autowired 方法正在生成此问题（如果我从另一个 @Bean 定义方法中调用该方法，则不会发生这种情况)。

然后解决方案是将逻辑移动到不同的@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");
    }
}

之所以会出现在新的 Boot 版本中，是因为 Boot 现在默认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，我还可以通过在我的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