java - Spring中的@Component、@Repository和@Service注解有什么区别？

Question

可以@Component , @Repository和 @Service注释在 Spring 中可以互换使用，还是除了充当注释设备之外，它们还提供任何特定功能吗？

换句话说，如果我有一个 Service 类并且我将注解从 @Service 更改为 @Component，它的行为方式是否仍然相同？

或者注解也会影响类的行为和功能？

Answer 1

来自 Spring Documentation :

The @Repository annotation is a marker for any class that fulfils the role or stereotype of a repository (also known as Data Access Object or DAO). Among the uses of this marker is the automatic translation of exceptions, as described in Exception Translation.

Spring provides further stereotype annotations: @Component, @Service, and @Controller. @Component is a generic stereotype for any Spring-managed component. @Repository, @Service, and @Controller are specializations of @Component for more specific use cases (in the persistence, service, and presentation layers, respectively). Therefore, you can annotate your component classes with @Component, but, by annotating them with @Repository, @Service, or @Controller instead, your classes are more properly suited for processing by tools or associating with aspects.

For example, these stereotype annotations make ideal targets for pointcuts. @Repository, @Service, and @Controller can also carry additional semantics in future releases of the Spring Framework. Thus, if you are choosing between using @Component or @Service for your service layer, @Service is clearly the better choice. Similarly, as stated earlier, @Repository is already supported as a marker for automatic exception translation in your persistence layer.

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注释	意义
@Component	任何 Spring 管理组件的通用构造型
@Repository	持久层的原型(prototype)
@Service	服务层的原型(prototype)
@Controller	表示层的原型(prototype)(spring-mvc)