Java 尽管使用了@Primary，但两个具有相同名称的 bean 仍会导致 ConflictingBeanDefinitionException
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Two beans with the same name results in ConflictingBeanDefinitionException despite using @Primary
提问by fracz
I have an application initializer class that is used to insert application specific data to database.
我有一个应用程序初始值设定项类，用于将特定于应用程序的数据插入数据库。
@Component("applicationInitializer")
public class ApplicationInitializer {
@PostConstruct
public void init(){
// some clever code here
}
}
There is also DevApplicationInitializerclass that is used to initialize database with some sample data on developer machine (this class is excluded when deploying production code).
还有一个DevApplicationInitializer类用于在开发人员机器上使用一些示例数据初始化数据库（部署生产代码时排除该类）。
@Component("applicationInitializer")
@Primary
public class DevApplicationInitializer extends ApplicationInitializer {
@PostConstruct
@Override
public void init(){
super.init();
// even more clever code here
}
}
Until I have given a name for the beans (only the @Componentannotations) - everything worked fine - when DevApplicationInitializerwas available, it was instantiated instead of ApplicationInitializer. When I gave them an applicationInitializername, the exception is being thrown:
直到我为 bean 命名（只有@Component注释） - 一切正常 - 当DevApplicationInitializer可用时，它被实例化而不是ApplicationInitializer. 当我给他们一个applicationInitializer名字时，抛出异常：
org.springframework.context.annotation.ConflictingBeanDefinitionException:
Annotation-specified bean name 'applicationInitializer' for bean class
[com.example.DevApplicationInitializer] conflicts with existing, non-compatible
bean definition of same name and class [com.example.ApplicationInitializer]
Why the @Primaryannotation is not respected when beans have name? I need them to have one, because I ensure in other place that the initializer has been instantiated with @DependsOn("applicationInitializer")annotation.
@Primary当 bean 有名称时，为什么不尊重注释？我需要他们拥有一个，因为我确保在其他地方初始化器已使用@DependsOn("applicationInitializer")注释实例化。
采纳答案by Sotirios Delimanolis
@Primaryhas no relation to bean names. The javadoc states
@Primary与 bean 名称无关。javadoc 指出
Indicates that a bean should be given preference when multiple candidates are qualified to autowire a single-valued dependency.
指示当多个候选者有资格自动装配单值依赖项时，应该优先考虑一个 bean。
This only applies to a context containing two beans of some type Awhere a bean of type Brequires an Ato be injected. The A bean annotated with @Primarywill have priority.
这仅适用于包含某种类型的两个 bean 的上下文，A其中一个类型的 beanB需要A被注入。带有注释的 A bean@Primary将具有优先权。
Bean ids/names for a given type must be unique. (Bean definitions with the same name can overwrite each other for the same bean type. For example, this would happen if you component scanned a class annotated with @Componentbut also provided a @Beanmethod for that same type.)
给定类型的 Bean id/名称必须是唯一的。（对于相同的 bean 类型，具有相同名称的 Bean 定义可以相互覆盖。例如，如果您的组件扫描了一个注释的类，@Component但也@Bean为该相同类型提供了一个方法，就会发生这种情况。）
