Spring 启动 - 单个 @Configuration @import 可以工作，但多个不能，为什么？

Question

在 Spring 引导项目中，我有一个 RestController 包含：

@Autowired
private ProactiveDbManager proactiveDbManager;

@Autowired
private CoreDbManager coreDbManager;

这 2 个数据库管理器位于另一个 Spring 引导模块中，因此我使用配置 class:

导入它们

@Configuration
@PropertySource("classpath:application.properties")
@Import({ProactiveDbCommonsConfig.class})
public class ProactiveDbConfig {

}

和：

@Configuration
@PropertySource("classpath:application.properties")
@Import({CoreDbCommonsConfig.class})
public class CoreDbConfig {

}

ProactiveDbCommonsConfig和CoreDbCommonsConfig也是配置。 ProactiveDbCommonsConfig:

@Configuration
public class ProactiveDbCommonsConfig {
    private static final Logger LOGGER = LoggerFactory.getLogger(ProactiveDbCommonsConfig.class);

    private ProactiveDbManager proactiveDbManager;
    @Bean
    public MasterHandler masterHandler() {
        return new MasterHandler(true);
    }

    @Bean
    public ProactiveDbManager dBManager(MasterHandler masterHandler) {
        List<String> dbConnectionStrings = masterHandler.getDbConnectionStringsJsonsList(DbConsts.DEFAULT_DATA_CENTER);
        LOGGER.debug("DB manager created.");
        proactiveDbManager = new ProactiveDbManager(dbConnectionStrings);
        return proactiveDbManager;
    }


    @Override
    protected void finalize() {
        try {
            closeDbConnection();
        } catch (Exception ignored) {
        }
    }

    @PreDestroy
    public void closeDbConnection() throws Exception {
        if (this.proactiveDbManager != null) {
            this.proactiveDbManager.disconnect();
            this.proactiveDbManager = null;
        }
    }
}

我的问题是，如果我删除控制器中的 1 个自动装配并删除其配置（即 ProactiveDbConfig），那么它就可以工作了。他们两个都是单独工作，但不是一起工作。

我得到的错误是：

Field coreDbManager in x.y.z.controllers.h required a bean of type 'x.y.a.db.managers.CoreDbManager' that could not be found.

堆栈跟踪：

15:56:14.609 [main] DEBUG o.s.b.d.LoggingFailureAnalysisReporter - Application failed to start due to an exception
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'x.y.db.managers.CoreDbManager' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
    at x.y.app.MyApp.main(MyApp.java:10)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:66)
15:56:14.609 [main] ERROR o.s.b.d.LoggingFailureAnalysisReporter -

Answer 1

当使用 @Configuration 类且未在 @Bean(name = "<your-name-here>") 中明确定义 bean 名称时，方法名称将用作 bean 的名称。

如果您导入多个包含同名 bean 的配置文件，一个将覆盖另一个。 Spring Boot 的较新版本通过禁用覆盖（默认情况下启用）来防止这种情况，这将导致启动时出现异常。

对于您的解决方案，重命名方法或向 @Bean 注释添加显式名称。

Spring 启动 - 单个 @Configuration @import 可以工作，但多个不能，为什么？

Spring boot - A single @Configuration @import will work but multiple will not, why?

java

spring

spring-boot

autowired